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Write the same code in Java as shown below in C++.
#include <iostream> #include <map> class van_eck_generator { public: int next() { int result = last_term; auto iter = last_pos.find(last_term); int next_term = (iter != last_pos.end()) ? index - iter->second : 0; last_pos[last_term] = index; last_term = next_term; ++index; return result; } private: int index = 0; int last_term = 0; std::map<int, int> last_pos; }; int main() { van_eck_generator gen; int i = 0; std::cout << "First 10 terms of the Van Eck sequence:\n"; for (; i < 10; ++i) std::cout << gen.next() << ' '; for (; i < 990; ++i) gen.next(); std::cout << "\nTerms 991 to 1000 of the sequence:\n"; for (; i < 1000; ++i) std::cout << gen.next() << ' '; std::cout << '\n'; return 0; }
import java.util.HashMap; import java.util.Map; public class VanEckSequence { public static void main(String[] args) { System.out.println("First 10 terms of Van Eck's sequence:"); vanEck(1, 10); System.out.println(""); System.out.println("Terms 991 to 1000 of Van Eck's sequence:"); vanEck(991, 1000); } private static void vanEck(int firstIndex, int lastIndex) { Map<Integer,Integer> vanEckMap = new HashMap<>(); int last = 0; if ( firstIndex == 1 ) { System.out.printf("VanEck[%d] = %d%n", 1, 0); } for ( int n = 2 ; n <= lastIndex ; n++ ) { int vanEck = vanEckMap.containsKey(last) ? n - vanEckMap.get(last) : 0; vanEckMap.put(last, n); last = vanEck; if ( n >= firstIndex ) { System.out.printf("VanEck[%d] = %d%n", n, vanEck); } } } }
Transform the following C++ implementation into Java, maintaining the same output and logic.
#include <iostream> #include <map> class van_eck_generator { public: int next() { int result = last_term; auto iter = last_pos.find(last_term); int next_term = (iter != last_pos.end()) ? index - iter->second : 0; last_pos[last_term] = index; last_term = next_term; ++index; return result; } private: int index = 0; int last_term = 0; std::map<int, int> last_pos; }; int main() { van_eck_generator gen; int i = 0; std::cout << "First 10 terms of the Van Eck sequence:\n"; for (; i < 10; ++i) std::cout << gen.next() << ' '; for (; i < 990; ++i) gen.next(); std::cout << "\nTerms 991 to 1000 of the sequence:\n"; for (; i < 1000; ++i) std::cout << gen.next() << ' '; std::cout << '\n'; return 0; }
import java.util.HashMap; import java.util.Map; public class VanEckSequence { public static void main(String[] args) { System.out.println("First 10 terms of Van Eck's sequence:"); vanEck(1, 10); System.out.println(""); System.out.println("Terms 991 to 1000 of Van Eck's sequence:"); vanEck(991, 1000); } private static void vanEck(int firstIndex, int lastIndex) { Map<Integer,Integer> vanEckMap = new HashMap<>(); int last = 0; if ( firstIndex == 1 ) { System.out.printf("VanEck[%d] = %d%n", 1, 0); } for ( int n = 2 ; n <= lastIndex ; n++ ) { int vanEck = vanEckMap.containsKey(last) ? n - vanEckMap.get(last) : 0; vanEckMap.put(last, n); last = vanEck; if ( n >= firstIndex ) { System.out.printf("VanEck[%d] = %d%n", n, vanEck); } } } }
Convert the following code from C++ to Java, ensuring the logic remains intact.
#include <iostream> #include <string> #include <cstring> #include <fstream> #include <sys/stat.h> #include <ftplib.h> #include <ftp++.hpp> int stat(const char *pathname, struct stat *buf); char *strerror(int errnum); char *basename(char *path); namespace stl { using std::cout; using std::cerr; using std::string; using std::ifstream; using std::remove; }; using namespace stl; using Mode = ftp::Connection::Mode; Mode PASV = Mode::PASSIVE; Mode PORT = Mode::PORT; using TransferMode = ftp::Connection::TransferMode; TransferMode BINARY = TransferMode::BINARY; TransferMode TEXT = TransferMode::TEXT; struct session { const string server; const string port; const string user; const string pass; Mode mode; TransferMode txmode; string dir; }; ftp::Connection connect_ftp( const session& sess); size_t get_ftp( ftp::Connection& conn, string const& path); string readFile( const string& filename); string login_ftp(ftp::Connection& conn, const session& sess); string dir_listing( ftp::Connection& conn, const string& path); string readFile( const string& filename) { struct stat stat_buf; string contents; errno = 0; if (stat(filename.c_str() , &stat_buf) != -1) { size_t len = stat_buf.st_size; string bytes(len+1, '\0'); ifstream ifs(filename); ifs.read(&bytes[0], len); if (! ifs.fail() ) contents.swap(bytes); ifs.close(); } else { cerr << "stat error: " << strerror(errno); } return contents; } ftp::Connection connect_ftp( const session& sess) try { string constr = sess.server + ":" + sess.port; cerr << "connecting to " << constr << " ...\n"; ftp::Connection conn{ constr.c_str() }; cerr << "connected to " << constr << "\n"; conn.setConnectionMode(sess.mode); return conn; } catch (ftp::ConnectException e) { cerr << "FTP error: could not connect to server" << "\n"; } string login_ftp(ftp::Connection& conn, const session& sess) { conn.login(sess.user.c_str() , sess.pass.c_str() ); return conn.getLastResponse(); } string dir_listing( ftp::Connection& conn, const string& path) try { const char* dirdata = "/dev/shm/dirdata"; conn.getList(dirdata, path.c_str() ); string dir_string = readFile(dirdata); cerr << conn.getLastResponse() << "\n"; errno = 0; if ( remove(dirdata) != 0 ) { cerr << "error: " << strerror(errno) << "\n"; } return dir_string; } catch (...) { cerr << "error: getting dir contents: \n" << strerror(errno) << "\n"; } size_t get_ftp( ftp::Connection& conn, const string& r_path) { size_t received = 0; const char* path = r_path.c_str(); unsigned remotefile_size = conn.size(path , BINARY); const char* localfile = basename(path); conn.get(localfile, path, BINARY); cerr << conn.getLastResponse() << "\n"; struct stat stat_buf; errno = 0; if (stat(localfile, &stat_buf) != -1) received = stat_buf.st_size; else cerr << strerror(errno); return received; } const session sonic { "mirrors.sonic.net", "21" , "anonymous", "xxxx@nohost.org", PASV, BINARY, "/pub/OpenBSD" }; int main(int argc, char* argv[], char * env[] ) { const session remote = sonic; try { ftp::Connection conn = connect_ftp(remote); cerr << login_ftp(conn, remote); cout << "System type: " << conn.getSystemType() << "\n"; cerr << conn.getLastResponse() << "\n"; conn.cd(remote.dir.c_str()); cerr << conn.getLastResponse() << "\n"; string pwdstr = conn.getDirectory(); cout << "PWD: " << pwdstr << "\n"; cerr << conn.getLastResponse() << "\n"; string dirlist = dir_listing(conn, pwdstr.c_str() ); cout << dirlist << "\n"; string filename = "ftplist"; auto pos = dirlist.find(filename); auto notfound = string::npos; if (pos != notfound) { size_t received = get_ftp(conn, filename.c_str() ); if (received == 0) cerr << "got 0 bytes\n"; else cerr << "got " << filename << " (" << received << " bytes)\n"; } else { cerr << "file " << filename << "not found on server. \n"; } } catch (ftp::ConnectException e) { cerr << "FTP error: could not connect to server" << "\n"; } catch (ftp::Exception e) { cerr << "FTP error: " << e << "\n"; } catch (...) { cerr << "error: " << strerror(errno) << "\n"; } return 0; }
import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import org.apache.commons.net.ftp.FTP; import org.apache.commons.net.ftp.FTPClient; import org.apache.commons.net.ftp.FTPFile; import org.apache.commons.net.ftp.FTPReply; public class FTPconn { public static void main(String[] args) throws IOException { String server = "ftp.hq.nasa.gov"; int port = 21; String user = "anonymous"; String pass = "ftptest@example.com"; OutputStream output = null; FTPClient ftpClient = new FTPClient(); try { ftpClient.connect(server, port); serverReply(ftpClient); int replyCode = ftpClient.getReplyCode(); if (!FTPReply.isPositiveCompletion(replyCode)) { System.out.println("Failure. Server reply code: " + replyCode); return; } serverReply(ftpClient); if (!ftpClient.login(user, pass)) { System.out.println("Could not login to the server."); return; } String dir = "pub/issoutreach/Living in Space Stories (MP3 Files)/"; if (!ftpClient.changeWorkingDirectory(dir)) { System.out.println("Change directory failed."); return; } ftpClient.enterLocalPassiveMode(); for (FTPFile file : ftpClient.listFiles()) System.out.println(file); String filename = "Can People go to Mars.mp3"; output = new FileOutputStream(filename); ftpClient.setFileType(FTP.BINARY_FILE_TYPE); if (!ftpClient.retrieveFile(filename, output)) { System.out.println("Retrieving file failed"); return; } serverReply(ftpClient); ftpClient.logout(); } finally { if (output != null) output.close(); } } private static void serverReply(FTPClient ftpClient) { for (String reply : ftpClient.getReplyStrings()) { System.out.println(reply); } } }
Maintain the same structure and functionality when rewriting this code in Java.
#include <iostream> #include <string> #include <cstring> #include <fstream> #include <sys/stat.h> #include <ftplib.h> #include <ftp++.hpp> int stat(const char *pathname, struct stat *buf); char *strerror(int errnum); char *basename(char *path); namespace stl { using std::cout; using std::cerr; using std::string; using std::ifstream; using std::remove; }; using namespace stl; using Mode = ftp::Connection::Mode; Mode PASV = Mode::PASSIVE; Mode PORT = Mode::PORT; using TransferMode = ftp::Connection::TransferMode; TransferMode BINARY = TransferMode::BINARY; TransferMode TEXT = TransferMode::TEXT; struct session { const string server; const string port; const string user; const string pass; Mode mode; TransferMode txmode; string dir; }; ftp::Connection connect_ftp( const session& sess); size_t get_ftp( ftp::Connection& conn, string const& path); string readFile( const string& filename); string login_ftp(ftp::Connection& conn, const session& sess); string dir_listing( ftp::Connection& conn, const string& path); string readFile( const string& filename) { struct stat stat_buf; string contents; errno = 0; if (stat(filename.c_str() , &stat_buf) != -1) { size_t len = stat_buf.st_size; string bytes(len+1, '\0'); ifstream ifs(filename); ifs.read(&bytes[0], len); if (! ifs.fail() ) contents.swap(bytes); ifs.close(); } else { cerr << "stat error: " << strerror(errno); } return contents; } ftp::Connection connect_ftp( const session& sess) try { string constr = sess.server + ":" + sess.port; cerr << "connecting to " << constr << " ...\n"; ftp::Connection conn{ constr.c_str() }; cerr << "connected to " << constr << "\n"; conn.setConnectionMode(sess.mode); return conn; } catch (ftp::ConnectException e) { cerr << "FTP error: could not connect to server" << "\n"; } string login_ftp(ftp::Connection& conn, const session& sess) { conn.login(sess.user.c_str() , sess.pass.c_str() ); return conn.getLastResponse(); } string dir_listing( ftp::Connection& conn, const string& path) try { const char* dirdata = "/dev/shm/dirdata"; conn.getList(dirdata, path.c_str() ); string dir_string = readFile(dirdata); cerr << conn.getLastResponse() << "\n"; errno = 0; if ( remove(dirdata) != 0 ) { cerr << "error: " << strerror(errno) << "\n"; } return dir_string; } catch (...) { cerr << "error: getting dir contents: \n" << strerror(errno) << "\n"; } size_t get_ftp( ftp::Connection& conn, const string& r_path) { size_t received = 0; const char* path = r_path.c_str(); unsigned remotefile_size = conn.size(path , BINARY); const char* localfile = basename(path); conn.get(localfile, path, BINARY); cerr << conn.getLastResponse() << "\n"; struct stat stat_buf; errno = 0; if (stat(localfile, &stat_buf) != -1) received = stat_buf.st_size; else cerr << strerror(errno); return received; } const session sonic { "mirrors.sonic.net", "21" , "anonymous", "xxxx@nohost.org", PASV, BINARY, "/pub/OpenBSD" }; int main(int argc, char* argv[], char * env[] ) { const session remote = sonic; try { ftp::Connection conn = connect_ftp(remote); cerr << login_ftp(conn, remote); cout << "System type: " << conn.getSystemType() << "\n"; cerr << conn.getLastResponse() << "\n"; conn.cd(remote.dir.c_str()); cerr << conn.getLastResponse() << "\n"; string pwdstr = conn.getDirectory(); cout << "PWD: " << pwdstr << "\n"; cerr << conn.getLastResponse() << "\n"; string dirlist = dir_listing(conn, pwdstr.c_str() ); cout << dirlist << "\n"; string filename = "ftplist"; auto pos = dirlist.find(filename); auto notfound = string::npos; if (pos != notfound) { size_t received = get_ftp(conn, filename.c_str() ); if (received == 0) cerr << "got 0 bytes\n"; else cerr << "got " << filename << " (" << received << " bytes)\n"; } else { cerr << "file " << filename << "not found on server. \n"; } } catch (ftp::ConnectException e) { cerr << "FTP error: could not connect to server" << "\n"; } catch (ftp::Exception e) { cerr << "FTP error: " << e << "\n"; } catch (...) { cerr << "error: " << strerror(errno) << "\n"; } return 0; }
import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import org.apache.commons.net.ftp.FTP; import org.apache.commons.net.ftp.FTPClient; import org.apache.commons.net.ftp.FTPFile; import org.apache.commons.net.ftp.FTPReply; public class FTPconn { public static void main(String[] args) throws IOException { String server = "ftp.hq.nasa.gov"; int port = 21; String user = "anonymous"; String pass = "ftptest@example.com"; OutputStream output = null; FTPClient ftpClient = new FTPClient(); try { ftpClient.connect(server, port); serverReply(ftpClient); int replyCode = ftpClient.getReplyCode(); if (!FTPReply.isPositiveCompletion(replyCode)) { System.out.println("Failure. Server reply code: " + replyCode); return; } serverReply(ftpClient); if (!ftpClient.login(user, pass)) { System.out.println("Could not login to the server."); return; } String dir = "pub/issoutreach/Living in Space Stories (MP3 Files)/"; if (!ftpClient.changeWorkingDirectory(dir)) { System.out.println("Change directory failed."); return; } ftpClient.enterLocalPassiveMode(); for (FTPFile file : ftpClient.listFiles()) System.out.println(file); String filename = "Can People go to Mars.mp3"; output = new FileOutputStream(filename); ftpClient.setFileType(FTP.BINARY_FILE_TYPE); if (!ftpClient.retrieveFile(filename, output)) { System.out.println("Retrieving file failed"); return; } serverReply(ftpClient); ftpClient.logout(); } finally { if (output != null) output.close(); } } private static void serverReply(FTPClient ftpClient) { for (String reply : ftpClient.getReplyStrings()) { System.out.println(reply); } } }
Port the following code from C++ to Java with equivalent syntax and logic.
#include <random> #include <iostream> #include <stack> #include <set> #include <string> #include <functional> using namespace std; class RPNParse { public: stack<double> stk; multiset<int> digits; void op(function<double(double,double)> f) { if(stk.size() < 2) throw "Improperly written expression"; int b = stk.top(); stk.pop(); int a = stk.top(); stk.pop(); stk.push(f(a, b)); } void parse(char c) { if(c >= '0' && c <= '9') { stk.push(c - '0'); digits.insert(c - '0'); } else if(c == '+') op([](double a, double b) {return a+b;}); else if(c == '-') op([](double a, double b) {return a-b;}); else if(c == '*') op([](double a, double b) {return a*b;}); else if(c == '/') op([](double a, double b) {return a/b;}); } void parse(string s) { for(int i = 0; i < s.size(); ++i) parse(s[i]); } double getResult() { if(stk.size() != 1) throw "Improperly written expression"; return stk.top(); } }; int main() { random_device seed; mt19937 engine(seed()); uniform_int_distribution<> distribution(1, 9); auto rnd = bind(distribution, engine); multiset<int> digits; cout << "Make 24 with the digits: "; for(int i = 0; i < 4; ++i) { int n = rnd(); cout << " " << n; digits.insert(n); } cout << endl; RPNParse parser; try { string input; getline(cin, input); parser.parse(input); if(digits != parser.digits) cout << "Error: Not using the given digits" << endl; else { double r = parser.getResult(); cout << "Result: " << r << endl; if(r > 23.999 && r < 24.001) cout << "Good job!" << endl; else cout << "Try again." << endl; } } catch(char* e) { cout << "Error: " << e << endl; } return 0; }
import java.util.*; public class Game24 { static Random r = new Random(); public static void main(String[] args) { int[] digits = randomDigits(); Scanner in = new Scanner(System.in); System.out.print("Make 24 using these digits: "); System.out.println(Arrays.toString(digits)); System.out.print("> "); Stack<Float> s = new Stack<>(); long total = 0; for (char c : in.nextLine().toCharArray()) { if ('0' <= c && c <= '9') { int d = c - '0'; total += (1 << (d * 5)); s.push((float) d); } else if ("+/-*".indexOf(c) != -1) { s.push(applyOperator(s.pop(), s.pop(), c)); } } if (tallyDigits(digits) != total) System.out.print("Not the same digits. "); else if (Math.abs(24 - s.peek()) < 0.001F) System.out.println("Correct!"); else System.out.print("Not correct."); } static float applyOperator(float a, float b, char c) { switch (c) { case '+': return a + b; case '-': return b - a; case '*': return a * b; case '/': return b / a; default: return Float.NaN; } } static long tallyDigits(int[] a) { long total = 0; for (int i = 0; i < 4; i++) total += (1 << (a[i] * 5)); return total; } static int[] randomDigits() { int[] result = new int[4]; for (int i = 0; i < 4; i++) result[i] = r.nextInt(9) + 1; return result; } }
Rewrite the snippet below in Java so it works the same as the original C++ code.
#include <random> #include <iostream> #include <stack> #include <set> #include <string> #include <functional> using namespace std; class RPNParse { public: stack<double> stk; multiset<int> digits; void op(function<double(double,double)> f) { if(stk.size() < 2) throw "Improperly written expression"; int b = stk.top(); stk.pop(); int a = stk.top(); stk.pop(); stk.push(f(a, b)); } void parse(char c) { if(c >= '0' && c <= '9') { stk.push(c - '0'); digits.insert(c - '0'); } else if(c == '+') op([](double a, double b) {return a+b;}); else if(c == '-') op([](double a, double b) {return a-b;}); else if(c == '*') op([](double a, double b) {return a*b;}); else if(c == '/') op([](double a, double b) {return a/b;}); } void parse(string s) { for(int i = 0; i < s.size(); ++i) parse(s[i]); } double getResult() { if(stk.size() != 1) throw "Improperly written expression"; return stk.top(); } }; int main() { random_device seed; mt19937 engine(seed()); uniform_int_distribution<> distribution(1, 9); auto rnd = bind(distribution, engine); multiset<int> digits; cout << "Make 24 with the digits: "; for(int i = 0; i < 4; ++i) { int n = rnd(); cout << " " << n; digits.insert(n); } cout << endl; RPNParse parser; try { string input; getline(cin, input); parser.parse(input); if(digits != parser.digits) cout << "Error: Not using the given digits" << endl; else { double r = parser.getResult(); cout << "Result: " << r << endl; if(r > 23.999 && r < 24.001) cout << "Good job!" << endl; else cout << "Try again." << endl; } } catch(char* e) { cout << "Error: " << e << endl; } return 0; }
import java.util.*; public class Game24 { static Random r = new Random(); public static void main(String[] args) { int[] digits = randomDigits(); Scanner in = new Scanner(System.in); System.out.print("Make 24 using these digits: "); System.out.println(Arrays.toString(digits)); System.out.print("> "); Stack<Float> s = new Stack<>(); long total = 0; for (char c : in.nextLine().toCharArray()) { if ('0' <= c && c <= '9') { int d = c - '0'; total += (1 << (d * 5)); s.push((float) d); } else if ("+/-*".indexOf(c) != -1) { s.push(applyOperator(s.pop(), s.pop(), c)); } } if (tallyDigits(digits) != total) System.out.print("Not the same digits. "); else if (Math.abs(24 - s.peek()) < 0.001F) System.out.println("Correct!"); else System.out.print("Not correct."); } static float applyOperator(float a, float b, char c) { switch (c) { case '+': return a + b; case '-': return b - a; case '*': return a * b; case '/': return b / a; default: return Float.NaN; } } static long tallyDigits(int[] a) { long total = 0; for (int i = 0; i < 4; i++) total += (1 << (a[i] * 5)); return total; } static int[] randomDigits() { int[] result = new int[4]; for (int i = 0; i < 4; i++) result[i] = r.nextInt(9) + 1; return result; } }
Translate this program into Java but keep the logic exactly as in C++.
for(int i = 1;i <= 10; i++){ cout << i; if(i % 5 == 0){ cout << endl; continue; } cout << ", "; }
for(int i = 1;i <= 10; i++){ System.out.print(i); if(i % 5 == 0){ System.out.println(); continue; } System.out.print(", "); }
Keep all operations the same but rewrite the snippet in Java.
#ifndef MYWIDGET_H #define MYWIDGET_H #include <QWidget> class QPaintEvent ; class MyWidget : public QWidget { public : MyWidget( ) ; protected : void paintEvent( QPaintEvent * ) ; private : int width ; int height ; const int colornumber ; } ; #endif
import java.awt.Color; import java.awt.Graphics; import javax.swing.JFrame; public class ColorFrame extends JFrame { public ColorFrame(int width, int height) { this.setDefaultCloseOperation(EXIT_ON_CLOSE); this.setSize(width, height); this.setVisible(true); } @Override public void paint(Graphics g) { Color[] colors = { Color.black, Color.red, Color.green, Color.blue, Color.pink, Color.CYAN, Color.yellow, Color.white }; for (int i = 0; i < colors.length; i++) { g.setColor(colors[i]); g.fillRect(this.getWidth() / colors.length * i, 0, this.getWidth() / colors.length, this.getHeight()); } } public static void main(String args[]) { new ColorFrame(200, 200); } }
Convert this C++ snippet to Java and keep its semantics consistent.
#ifndef MYWIDGET_H #define MYWIDGET_H #include <QWidget> class QPaintEvent ; class MyWidget : public QWidget { public : MyWidget( ) ; protected : void paintEvent( QPaintEvent * ) ; private : int width ; int height ; const int colornumber ; } ; #endif
import java.awt.Color; import java.awt.Graphics; import javax.swing.JFrame; public class ColorFrame extends JFrame { public ColorFrame(int width, int height) { this.setDefaultCloseOperation(EXIT_ON_CLOSE); this.setSize(width, height); this.setVisible(true); } @Override public void paint(Graphics g) { Color[] colors = { Color.black, Color.red, Color.green, Color.blue, Color.pink, Color.CYAN, Color.yellow, Color.white }; for (int i = 0; i < colors.length; i++) { g.setColor(colors[i]); g.fillRect(this.getWidth() / colors.length * i, 0, this.getWidth() / colors.length, this.getHeight()); } } public static void main(String args[]) { new ColorFrame(200, 200); } }
Translate the given C++ code snippet into Java without altering its behavior.
#include <cassert> #include <cmath> #include <iomanip> #include <iostream> #include <limits> #include <numeric> #include <sstream> #include <vector> template <typename scalar_type> class matrix { public: matrix(size_t rows, size_t columns) : rows_(rows), columns_(columns), elements_(rows * columns) {} matrix(size_t rows, size_t columns, scalar_type value) : rows_(rows), columns_(columns), elements_(rows * columns, value) {} matrix(size_t rows, size_t columns, const std::initializer_list<std::initializer_list<scalar_type>>& values) : rows_(rows), columns_(columns), elements_(rows * columns) { assert(values.size() <= rows_); size_t i = 0; for (const auto& row : values) { assert(row.size() <= columns_); std::copy(begin(row), end(row), &elements_[i]); i += columns_; } } size_t rows() const { return rows_; } size_t columns() const { return columns_; } const scalar_type& operator()(size_t row, size_t column) const { assert(row < rows_); assert(column < columns_); return elements_[row * columns_ + column]; } scalar_type& operator()(size_t row, size_t column) { assert(row < rows_); assert(column < columns_); return elements_[row * columns_ + column]; } private: size_t rows_; size_t columns_; std::vector<scalar_type> elements_; }; template <typename scalar_type> void print(std::wostream& out, const matrix<scalar_type>& a) { const wchar_t* box_top_left = L"\x23a1"; const wchar_t* box_top_right = L"\x23a4"; const wchar_t* box_left = L"\x23a2"; const wchar_t* box_right = L"\x23a5"; const wchar_t* box_bottom_left = L"\x23a3"; const wchar_t* box_bottom_right = L"\x23a6"; const int precision = 5; size_t rows = a.rows(), columns = a.columns(); std::vector<size_t> width(columns); for (size_t column = 0; column < columns; ++column) { size_t max_width = 0; for (size_t row = 0; row < rows; ++row) { std::ostringstream str; str << std::fixed << std::setprecision(precision) << a(row, column); max_width = std::max(max_width, str.str().length()); } width[column] = max_width; } out << std::fixed << std::setprecision(precision); for (size_t row = 0; row < rows; ++row) { const bool top(row == 0), bottom(row + 1 == rows); out << (top ? box_top_left : (bottom ? box_bottom_left : box_left)); for (size_t column = 0; column < columns; ++column) { if (column > 0) out << L' '; out << std::setw(width[column]) << a(row, column); } out << (top ? box_top_right : (bottom ? box_bottom_right : box_right)); out << L'\n'; } } template <typename scalar_type> auto lu_decompose(const matrix<scalar_type>& input) { assert(input.rows() == input.columns()); size_t n = input.rows(); std::vector<size_t> perm(n); std::iota(perm.begin(), perm.end(), 0); matrix<scalar_type> lower(n, n); matrix<scalar_type> upper(n, n); matrix<scalar_type> input1(input); for (size_t j = 0; j < n; ++j) { size_t max_index = j; scalar_type max_value = 0; for (size_t i = j; i < n; ++i) { scalar_type value = std::abs(input1(perm[i], j)); if (value > max_value) { max_index = i; max_value = value; } } if (max_value <= std::numeric_limits<scalar_type>::epsilon()) throw std::runtime_error("matrix is singular"); if (j != max_index) std::swap(perm[j], perm[max_index]); size_t jj = perm[j]; for (size_t i = j + 1; i < n; ++i) { size_t ii = perm[i]; input1(ii, j) /= input1(jj, j); for (size_t k = j + 1; k < n; ++k) input1(ii, k) -= input1(ii, j) * input1(jj, k); } } for (size_t j = 0; j < n; ++j) { lower(j, j) = 1; for (size_t i = j + 1; i < n; ++i) lower(i, j) = input1(perm[i], j); for (size_t i = 0; i <= j; ++i) upper(i, j) = input1(perm[i], j); } matrix<scalar_type> pivot(n, n); for (size_t i = 0; i < n; ++i) pivot(i, perm[i]) = 1; return std::make_tuple(lower, upper, pivot); } template <typename scalar_type> void show_lu_decomposition(const matrix<scalar_type>& input) { try { std::wcout << L"A\n"; print(std::wcout, input); auto result(lu_decompose(input)); std::wcout << L"\nL\n"; print(std::wcout, std::get<0>(result)); std::wcout << L"\nU\n"; print(std::wcout, std::get<1>(result)); std::wcout << L"\nP\n"; print(std::wcout, std::get<2>(result)); } catch (const std::exception& ex) { std::cerr << ex.what() << '\n'; } } int main() { std::wcout.imbue(std::locale("")); std::wcout << L"Example 1:\n"; matrix<double> matrix1(3, 3, {{1, 3, 5}, {2, 4, 7}, {1, 1, 0}}); show_lu_decomposition(matrix1); std::wcout << '\n'; std::wcout << L"Example 2:\n"; matrix<double> matrix2(4, 4, {{11, 9, 24, 2}, {1, 5, 2, 6}, {3, 17, 18, 1}, {2, 5, 7, 1}}); show_lu_decomposition(matrix2); std::wcout << '\n'; std::wcout << L"Example 3:\n"; matrix<double> matrix3(3, 3, {{-5, -6, -3}, {-1, 0, -2}, {-3, -4, -7}}); show_lu_decomposition(matrix3); std::wcout << '\n'; std::wcout << L"Example 4:\n"; matrix<double> matrix4(3, 3, {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}); show_lu_decomposition(matrix4); return 0; }
import static java.util.Arrays.stream; import java.util.Locale; import static java.util.stream.IntStream.range; public class Test { static double dotProduct(double[] a, double[] b) { return range(0, a.length).mapToDouble(i -> a[i] * b[i]).sum(); } static double[][] matrixMul(double[][] A, double[][] B) { double[][] result = new double[A.length][B[0].length]; double[] aux = new double[B.length]; for (int j = 0; j < B[0].length; j++) { for (int k = 0; k < B.length; k++) aux[k] = B[k][j]; for (int i = 0; i < A.length; i++) result[i][j] = dotProduct(A[i], aux); } return result; } static double[][] pivotize(double[][] m) { int n = m.length; double[][] id = range(0, n).mapToObj(j -> range(0, n) .mapToDouble(i -> i == j ? 1 : 0).toArray()) .toArray(double[][]::new); for (int i = 0; i < n; i++) { double maxm = m[i][i]; int row = i; for (int j = i; j < n; j++) if (m[j][i] > maxm) { maxm = m[j][i]; row = j; } if (i != row) { double[] tmp = id[i]; id[i] = id[row]; id[row] = tmp; } } return id; } static double[][][] lu(double[][] A) { int n = A.length; double[][] L = new double[n][n]; double[][] U = new double[n][n]; double[][] P = pivotize(A); double[][] A2 = matrixMul(P, A); for (int j = 0; j < n; j++) { L[j][j] = 1; for (int i = 0; i < j + 1; i++) { double s1 = 0; for (int k = 0; k < i; k++) s1 += U[k][j] * L[i][k]; U[i][j] = A2[i][j] - s1; } for (int i = j; i < n; i++) { double s2 = 0; for (int k = 0; k < j; k++) s2 += U[k][j] * L[i][k]; L[i][j] = (A2[i][j] - s2) / U[j][j]; } } return new double[][][]{L, U, P}; } static void print(double[][] m) { stream(m).forEach(a -> { stream(a).forEach(n -> System.out.printf(Locale.US, "%5.1f ", n)); System.out.println(); }); System.out.println(); } public static void main(String[] args) { double[][] a = {{1.0, 3, 5}, {2.0, 4, 7}, {1.0, 1, 0}}; double[][] b = {{11.0, 9, 24, 2}, {1.0, 5, 2, 6}, {3.0, 17, 18, 1}, {2.0, 5, 7, 1}}; for (double[][] m : lu(a)) print(m); System.out.println(); for (double[][] m : lu(b)) print(m); } }
Port the following code from C++ to Java with equivalent syntax and logic.
#include <algorithm> #include <iostream> #include <vector> #include <string> class pair { public: pair( int s, std::string z ) { p = std::make_pair( s, z ); } bool operator < ( const pair& o ) const { return i() < o.i(); } int i() const { return p.first; } std::string s() const { return p.second; } private: std::pair<int, std::string> p; }; void gFizzBuzz( int c, std::vector<pair>& v ) { bool output; for( int x = 1; x <= c; x++ ) { output = false; for( std::vector<pair>::iterator i = v.begin(); i != v.end(); i++ ) { if( !( x % ( *i ).i() ) ) { std::cout << ( *i ).s(); output = true; } } if( !output ) std::cout << x; std::cout << "\n"; } } int main( int argc, char* argv[] ) { std::vector<pair> v; v.push_back( pair( 7, "Baxx" ) ); v.push_back( pair( 3, "Fizz" ) ); v.push_back( pair( 5, "Buzz" ) ); std::sort( v.begin(), v.end() ); gFizzBuzz( 20, v ); return 0; }
public class FizzBuzz { public static void main(String[] args) { Sound[] sounds = {new Sound(3, "Fizz"), new Sound(5, "Buzz"), new Sound(7, "Baxx")}; for (int i = 1; i <= 20; i++) { StringBuilder sb = new StringBuilder(); for (Sound sound : sounds) { sb.append(sound.generate(i)); } System.out.println(sb.length() == 0 ? i : sb.toString()); } } private static class Sound { private final int trigger; private final String onomatopoeia; public Sound(int trigger, String onomatopoeia) { this.trigger = trigger; this.onomatopoeia = onomatopoeia; } public String generate(int i) { return i % trigger == 0 ? onomatopoeia : ""; } } }
Port the provided C++ code into Java while preserving the original functionality.
#include <string> #include <fstream> #include <iostream> int main( ) { std::cout << "Which file do you want to look at ?\n" ; std::string input ; std::getline( std::cin , input ) ; std::ifstream infile( input.c_str( ) , std::ios::in ) ; std::string file( input ) ; std::cout << "Which file line do you want to see ? ( Give a number > 0 ) ?\n" ; std::getline( std::cin , input ) ; int linenumber = std::stoi( input ) ; int lines_read = 0 ; std::string line ; if ( infile.is_open( ) ) { while ( infile ) { getline( infile , line ) ; lines_read++ ; if ( lines_read == linenumber ) { std::cout << line << std::endl ; break ; } } infile.close( ) ; if ( lines_read < linenumber ) std::cout << "No " << linenumber << " lines in " << file << " !\n" ; return 0 ; } else { std::cerr << "Could not find file " << file << " !\n" ; return 1 ; } }
package linenbr7; import java.io.*; public class LineNbr7 { public static void main(String[] args) throws Exception { File f = new File(args[0]); if (!f.isFile() || !f.canRead()) throw new IOException("can't read " + args[0]); BufferedReader br = new BufferedReader(new FileReader(f)); try (LineNumberReader lnr = new LineNumberReader(br)) { String line = null; int lnum = 0; while ((line = lnr.readLine()) != null && (lnum = lnr.getLineNumber()) < 7) { } switch (lnum) { case 0: System.out.println("the file has zero length"); break; case 7: boolean empty = "".equals(line); System.out.println("line 7: " + (empty ? "empty" : line)); break; default: System.out.println("the file has only " + lnum + " line(s)"); } } } }
Translate the given C++ code snippet into Java without altering its behavior.
#include <string> #include <fstream> #include <iostream> int main( ) { std::cout << "Which file do you want to look at ?\n" ; std::string input ; std::getline( std::cin , input ) ; std::ifstream infile( input.c_str( ) , std::ios::in ) ; std::string file( input ) ; std::cout << "Which file line do you want to see ? ( Give a number > 0 ) ?\n" ; std::getline( std::cin , input ) ; int linenumber = std::stoi( input ) ; int lines_read = 0 ; std::string line ; if ( infile.is_open( ) ) { while ( infile ) { getline( infile , line ) ; lines_read++ ; if ( lines_read == linenumber ) { std::cout << line << std::endl ; break ; } } infile.close( ) ; if ( lines_read < linenumber ) std::cout << "No " << linenumber << " lines in " << file << " !\n" ; return 0 ; } else { std::cerr << "Could not find file " << file << " !\n" ; return 1 ; } }
package linenbr7; import java.io.*; public class LineNbr7 { public static void main(String[] args) throws Exception { File f = new File(args[0]); if (!f.isFile() || !f.canRead()) throw new IOException("can't read " + args[0]); BufferedReader br = new BufferedReader(new FileReader(f)); try (LineNumberReader lnr = new LineNumberReader(br)) { String line = null; int lnum = 0; while ((line = lnr.readLine()) != null && (lnum = lnr.getLineNumber()) < 7) { } switch (lnum) { case 0: System.out.println("the file has zero length"); break; case 7: boolean empty = "".equals(line); System.out.println("line 7: " + (empty ? "empty" : line)); break; default: System.out.println("the file has only " + lnum + " line(s)"); } } } }
Convert the following code from C++ to Java, ensuring the logic remains intact.
#include <algorithm> #include <cctype> #include <iomanip> #include <iostream> #include <string> #include <vector> bool endsWithIgnoreCase(const std::string& str, const std::string& suffix) { const size_t n1 = str.length(); const size_t n2 = suffix.length(); if (n1 < n2) return false; return std::equal(str.begin() + (n1 - n2), str.end(), suffix.begin(), [](char c1, char c2) { return std::tolower(static_cast<unsigned char>(c1)) == std::tolower(static_cast<unsigned char>(c2)); }); } bool filenameHasExtension(const std::string& filename, const std::vector<std::string>& extensions) { return std::any_of(extensions.begin(), extensions.end(), [&filename](const std::string& extension) { return endsWithIgnoreCase(filename, "." + extension); }); } void test(const std::string& filename, const std::vector<std::string>& extensions) { std::cout << std::setw(20) << std::left << filename << ": " << std::boolalpha << filenameHasExtension(filename, extensions) << '\n'; } int main() { const std::vector<std::string> extensions{"zip", "rar", "7z", "gz", "archive", "A##", "tar.bz2"}; test("MyData.a##", extensions); test("MyData.tar.Gz", extensions); test("MyData.gzip", extensions); test("MyData.7z.backup", extensions); test("MyData...", extensions); test("MyData", extensions); test("MyData_v1.0.tar.bz2", extensions); test("MyData_v1.0.bz2", extensions); return 0; }
import java.util.Arrays; import java.util.Comparator; public class FileExt{ public static void main(String[] args){ String[] tests = {"text.txt", "text.TXT", "test.tar.gz", "test/test2.exe", "test\\test2.exe", "test", "a/b/c\\d/foo"}; String[] exts = {".txt",".gz","",".bat"}; System.out.println("Extensions: " + Arrays.toString(exts) + "\n"); for(String test:tests){ System.out.println(test +": " + extIsIn(test, exts)); } } public static boolean extIsIn(String test, String... exts){ int lastSlash = Math.max(test.lastIndexOf('/'), test.lastIndexOf('\\')); String filename = test.substring(lastSlash + 1); int lastDot = filename.lastIndexOf('.') == -1 ? filename.length() : filename.lastIndexOf('.'); String ext = filename.substring(lastDot); Arrays.sort(exts); return Arrays.binarySearch(exts, ext, new Comparator<String>() { @Override public int compare(String o1, String o2) { return o1.compareToIgnoreCase(o2); } }) >= 0; } }
Port the following code from C++ to Java with equivalent syntax and logic.
#include <algorithm> #include <cctype> #include <iomanip> #include <iostream> #include <string> #include <vector> bool endsWithIgnoreCase(const std::string& str, const std::string& suffix) { const size_t n1 = str.length(); const size_t n2 = suffix.length(); if (n1 < n2) return false; return std::equal(str.begin() + (n1 - n2), str.end(), suffix.begin(), [](char c1, char c2) { return std::tolower(static_cast<unsigned char>(c1)) == std::tolower(static_cast<unsigned char>(c2)); }); } bool filenameHasExtension(const std::string& filename, const std::vector<std::string>& extensions) { return std::any_of(extensions.begin(), extensions.end(), [&filename](const std::string& extension) { return endsWithIgnoreCase(filename, "." + extension); }); } void test(const std::string& filename, const std::vector<std::string>& extensions) { std::cout << std::setw(20) << std::left << filename << ": " << std::boolalpha << filenameHasExtension(filename, extensions) << '\n'; } int main() { const std::vector<std::string> extensions{"zip", "rar", "7z", "gz", "archive", "A##", "tar.bz2"}; test("MyData.a##", extensions); test("MyData.tar.Gz", extensions); test("MyData.gzip", extensions); test("MyData.7z.backup", extensions); test("MyData...", extensions); test("MyData", extensions); test("MyData_v1.0.tar.bz2", extensions); test("MyData_v1.0.bz2", extensions); return 0; }
import java.util.Arrays; import java.util.Comparator; public class FileExt{ public static void main(String[] args){ String[] tests = {"text.txt", "text.TXT", "test.tar.gz", "test/test2.exe", "test\\test2.exe", "test", "a/b/c\\d/foo"}; String[] exts = {".txt",".gz","",".bat"}; System.out.println("Extensions: " + Arrays.toString(exts) + "\n"); for(String test:tests){ System.out.println(test +": " + extIsIn(test, exts)); } } public static boolean extIsIn(String test, String... exts){ int lastSlash = Math.max(test.lastIndexOf('/'), test.lastIndexOf('\\')); String filename = test.substring(lastSlash + 1); int lastDot = filename.lastIndexOf('.') == -1 ? filename.length() : filename.lastIndexOf('.'); String ext = filename.substring(lastDot); Arrays.sort(exts); return Arrays.binarySearch(exts, ext, new Comparator<String>() { @Override public int compare(String o1, String o2) { return o1.compareToIgnoreCase(o2); } }) >= 0; } }
Translate this program into Java but keep the logic exactly as in C++.
#include <algorithm> #include <cctype> #include <iomanip> #include <iostream> #include <string> #include <vector> bool endsWithIgnoreCase(const std::string& str, const std::string& suffix) { const size_t n1 = str.length(); const size_t n2 = suffix.length(); if (n1 < n2) return false; return std::equal(str.begin() + (n1 - n2), str.end(), suffix.begin(), [](char c1, char c2) { return std::tolower(static_cast<unsigned char>(c1)) == std::tolower(static_cast<unsigned char>(c2)); }); } bool filenameHasExtension(const std::string& filename, const std::vector<std::string>& extensions) { return std::any_of(extensions.begin(), extensions.end(), [&filename](const std::string& extension) { return endsWithIgnoreCase(filename, "." + extension); }); } void test(const std::string& filename, const std::vector<std::string>& extensions) { std::cout << std::setw(20) << std::left << filename << ": " << std::boolalpha << filenameHasExtension(filename, extensions) << '\n'; } int main() { const std::vector<std::string> extensions{"zip", "rar", "7z", "gz", "archive", "A##", "tar.bz2"}; test("MyData.a##", extensions); test("MyData.tar.Gz", extensions); test("MyData.gzip", extensions); test("MyData.7z.backup", extensions); test("MyData...", extensions); test("MyData", extensions); test("MyData_v1.0.tar.bz2", extensions); test("MyData_v1.0.bz2", extensions); return 0; }
import java.util.Arrays; import java.util.Comparator; public class FileExt{ public static void main(String[] args){ String[] tests = {"text.txt", "text.TXT", "test.tar.gz", "test/test2.exe", "test\\test2.exe", "test", "a/b/c\\d/foo"}; String[] exts = {".txt",".gz","",".bat"}; System.out.println("Extensions: " + Arrays.toString(exts) + "\n"); for(String test:tests){ System.out.println(test +": " + extIsIn(test, exts)); } } public static boolean extIsIn(String test, String... exts){ int lastSlash = Math.max(test.lastIndexOf('/'), test.lastIndexOf('\\')); String filename = test.substring(lastSlash + 1); int lastDot = filename.lastIndexOf('.') == -1 ? filename.length() : filename.lastIndexOf('.'); String ext = filename.substring(lastDot); Arrays.sort(exts); return Arrays.binarySearch(exts, ext, new Comparator<String>() { @Override public int compare(String o1, String o2) { return o1.compareToIgnoreCase(o2); } }) >= 0; } }
Rewrite this program in Java while keeping its functionality equivalent to the C++ version.
#include <iostream> #include <ratio> #include <array> #include <algorithm> #include <random> typedef short int Digit; constexpr Digit nDigits{4}; constexpr Digit maximumDigit{9}; constexpr short int gameGoal{24}; typedef std::array<Digit, nDigits> digitSet; digitSet d; void printTrivialOperation(std::string operation) { bool printOperation(false); for(const Digit& number : d) { if(printOperation) std::cout << operation; else printOperation = true; std::cout << number; } std::cout << std::endl; } void printOperation(std::string prefix, std::string operation1, std::string operation2, std::string operation3, std::string suffix = "") { std::cout << prefix << d[0] << operation1 << d[1] << operation2 << d[2] << operation3 << d[3] << suffix << std::endl; } int main() { std::mt19937_64 randomGenerator; std::uniform_int_distribution<Digit> digitDistro{1, maximumDigit}; for(int trial{10}; trial; --trial) { for(Digit& digit : d) { digit = digitDistro(randomGenerator); std::cout << digit << " "; } std::cout << std::endl; std::sort(d.begin(), d.end()); if(std::accumulate(d.cbegin(), d.cend(), 0) == gameGoal) printTrivialOperation(" + "); if(std::accumulate(d.cbegin(), d.cend(), 1, std::multiplies<Digit>{}) == gameGoal) printTrivialOperation(" * "); do { if(d[0] + d[1] + d[2] - d[3] == gameGoal) printOperation("", " + ", " + ", " - "); if(d[0] * d[1] + d[2] + d[3] == gameGoal) printOperation("", " * ", " + ", " + "); if(d[0] * (d[1] + d[2]) + d[3] == gameGoal) printOperation("", " * ( ", " + ", " ) + "); if(d[0] * (d[1] + d[2] + d[3]) == gameGoal) printOperation("", " * ( ", " + ", " + ", " )"); if((d[0] * d[1] * d[2]) + d[3] == gameGoal) printOperation("( ", " * ", " * ", " ) + "); if(d[0] * d[1] * (d[2] + d[3]) == gameGoal) printOperation("( ", " * ", " * ( ", " + ", " )"); if((d[0] * d[1]) + (d[2] * d[3]) == gameGoal) printOperation("( ", " * ", " ) + ( ", " * ", " )"); if((d[0] * d[1] * d[2]) - d[3] == gameGoal) printOperation("( ", " * ", " * ", " ) - "); if(d[0] * d[1] * (d[2] - d[3]) == gameGoal) printOperation("( ", " * ", " * ( ", " - ", " )"); if((d[0] * d[1]) - (d[2] * d[3]) == gameGoal) printOperation("( ", " * ", " ) - ( ", " * ", " )"); if(d[0] * d[1] + d[2] - d[3] == gameGoal) printOperation("", " * ", " + ", " - "); if(d[0] * (d[1] + d[2]) - d[3] == gameGoal) printOperation("", " * ( ", " + ", " ) - "); if(d[0] * (d[1] - d[2]) + d[3] == gameGoal) printOperation("", " * ( ", " - ", " ) + "); if(d[0] * (d[1] + d[2] - d[3]) == gameGoal) printOperation("", " * ( ", " + ", " - ", " )"); if(d[0] * d[1] - (d[2] + d[3]) == gameGoal) printOperation("", " * ", " - ( ", " + ", " )"); if(d[0] * d[1] == (gameGoal - d[3]) * d[2]) printOperation("( ", " * ", " / ", " ) + "); if(((d[0] * d[1]) + d[2]) == gameGoal * d[3]) printOperation("(( ", " * ", " ) + ", " ) / "); if((d[0] + d[1]) * d[2] == gameGoal * d[3]) printOperation("(( ", " + ", " ) * ", " ) / "); if(d[0] * d[1] == gameGoal * (d[2] + d[3])) printOperation("( ", " * ", " ) / ( ", " + ", " )"); if(d[0] * d[1] == (gameGoal + d[3]) * d[2]) printOperation("( ", " * ", " / ", " ) - "); if(((d[0] * d[1]) - d[2]) == gameGoal * d[3]) printOperation("(( ", " * ", " ) - ", " ) / "); if((d[0] - d[1]) * d[2] == gameGoal * d[3]) printOperation("(( ", " - ", " ) * ", " ) / "); if(d[0] * d[1] == gameGoal * (d[2] - d[3])) printOperation("( ", " * ", " ) / ( ", " - ", " )"); if(d[0] * d[1] * d[2] == gameGoal * d[3]) printOperation("", " * ", " * ", " / "); if(d[0] * d[1] == gameGoal * d[2] * d[3]) printOperation("", " * ", " / ( ", " * ", " )"); if(d[0] * d[3] == gameGoal * (d[1] * d[3] - d[2])) printOperation("", " / ( ", " - ", " / ", " )"); if(d[0] * d[1] == gameGoal * d[2] * d[3]) printOperation("( ", " * ", " / ", " ) / ", ""); } while(std::next_permutation(d.begin(), d.end())); } return 0; }
import java.util.*; public class Game24Player { final String[] patterns = {"nnonnoo", "nnonono", "nnnoono", "nnnonoo", "nnnnooo"}; final String ops = "+-*/^"; String solution; List<Integer> digits; public static void main(String[] args) { new Game24Player().play(); } void play() { digits = getSolvableDigits(); Scanner in = new Scanner(System.in); while (true) { System.out.print("Make 24 using these digits: "); System.out.println(digits); System.out.println("(Enter 'q' to quit, 's' for a solution)"); System.out.print("> "); String line = in.nextLine(); if (line.equalsIgnoreCase("q")) { System.out.println("\nThanks for playing"); return; } if (line.equalsIgnoreCase("s")) { System.out.println(solution); digits = getSolvableDigits(); continue; } char[] entry = line.replaceAll("[^*+-/)(\\d]", "").toCharArray(); try { validate(entry); if (evaluate(infixToPostfix(entry))) { System.out.println("\nCorrect! Want to try another? "); digits = getSolvableDigits(); } else { System.out.println("\nNot correct."); } } catch (Exception e) { System.out.printf("%n%s Try again.%n", e.getMessage()); } } } void validate(char[] input) throws Exception { int total1 = 0, parens = 0, opsCount = 0; for (char c : input) { if (Character.isDigit(c)) total1 += 1 << (c - '0') * 4; else if (c == '(') parens++; else if (c == ')') parens--; else if (ops.indexOf(c) != -1) opsCount++; if (parens < 0) throw new Exception("Parentheses mismatch."); } if (parens != 0) throw new Exception("Parentheses mismatch."); if (opsCount != 3) throw new Exception("Wrong number of operators."); int total2 = 0; for (int d : digits) total2 += 1 << d * 4; if (total1 != total2) throw new Exception("Not the same digits."); } boolean evaluate(char[] line) throws Exception { Stack<Float> s = new Stack<>(); try { for (char c : line) { if ('0' <= c && c <= '9') s.push((float) c - '0'); else s.push(applyOperator(s.pop(), s.pop(), c)); } } catch (EmptyStackException e) { throw new Exception("Invalid entry."); } return (Math.abs(24 - s.peek()) < 0.001F); } float applyOperator(float a, float b, char c) { switch (c) { case '+': return a + b; case '-': return b - a; case '*': return a * b; case '/': return b / a; default: return Float.NaN; } } List<Integer> randomDigits() { Random r = new Random(); List<Integer> result = new ArrayList<>(4); for (int i = 0; i < 4; i++) result.add(r.nextInt(9) + 1); return result; } List<Integer> getSolvableDigits() { List<Integer> result; do { result = randomDigits(); } while (!isSolvable(result)); return result; } boolean isSolvable(List<Integer> digits) { Set<List<Integer>> dPerms = new HashSet<>(4 * 3 * 2); permute(digits, dPerms, 0); int total = 4 * 4 * 4; List<List<Integer>> oPerms = new ArrayList<>(total); permuteOperators(oPerms, 4, total); StringBuilder sb = new StringBuilder(4 + 3); for (String pattern : patterns) { char[] patternChars = pattern.toCharArray(); for (List<Integer> dig : dPerms) { for (List<Integer> opr : oPerms) { int i = 0, j = 0; for (char c : patternChars) { if (c == 'n') sb.append(dig.get(i++)); else sb.append(ops.charAt(opr.get(j++))); } String candidate = sb.toString(); try { if (evaluate(candidate.toCharArray())) { solution = postfixToInfix(candidate); return true; } } catch (Exception ignored) { } sb.setLength(0); } } } return false; } String postfixToInfix(String postfix) { class Expression { String op, ex; int prec = 3; Expression(String e) { ex = e; } Expression(String e1, String e2, String o) { ex = String.format("%s %s %s", e1, o, e2); op = o; prec = ops.indexOf(o) / 2; } } Stack<Expression> expr = new Stack<>(); for (char c : postfix.toCharArray()) { int idx = ops.indexOf(c); if (idx != -1) { Expression r = expr.pop(); Expression l = expr.pop(); int opPrec = idx / 2; if (l.prec < opPrec) l.ex = '(' + l.ex + ')'; if (r.prec <= opPrec) r.ex = '(' + r.ex + ')'; expr.push(new Expression(l.ex, r.ex, "" + c)); } else { expr.push(new Expression("" + c)); } } return expr.peek().ex; } char[] infixToPostfix(char[] infix) throws Exception { StringBuilder sb = new StringBuilder(); Stack<Integer> s = new Stack<>(); try { for (char c : infix) { int idx = ops.indexOf(c); if (idx != -1) { if (s.isEmpty()) s.push(idx); else { while (!s.isEmpty()) { int prec2 = s.peek() / 2; int prec1 = idx / 2; if (prec2 >= prec1) sb.append(ops.charAt(s.pop())); else break; } s.push(idx); } } else if (c == '(') { s.push(-2); } else if (c == ')') { while (s.peek() != -2) sb.append(ops.charAt(s.pop())); s.pop(); } else { sb.append(c); } } while (!s.isEmpty()) sb.append(ops.charAt(s.pop())); } catch (EmptyStackException e) { throw new Exception("Invalid entry."); } return sb.toString().toCharArray(); } void permute(List<Integer> lst, Set<List<Integer>> res, int k) { for (int i = k; i < lst.size(); i++) { Collections.swap(lst, i, k); permute(lst, res, k + 1); Collections.swap(lst, k, i); } if (k == lst.size()) res.add(new ArrayList<>(lst)); } void permuteOperators(List<List<Integer>> res, int n, int total) { for (int i = 0, npow = n * n; i < total; i++) res.add(Arrays.asList((i / npow), (i % npow) / n, i % n)); } }
Write the same algorithm in Java as shown in this C++ implementation.
#include <iostream> #include <ratio> #include <array> #include <algorithm> #include <random> typedef short int Digit; constexpr Digit nDigits{4}; constexpr Digit maximumDigit{9}; constexpr short int gameGoal{24}; typedef std::array<Digit, nDigits> digitSet; digitSet d; void printTrivialOperation(std::string operation) { bool printOperation(false); for(const Digit& number : d) { if(printOperation) std::cout << operation; else printOperation = true; std::cout << number; } std::cout << std::endl; } void printOperation(std::string prefix, std::string operation1, std::string operation2, std::string operation3, std::string suffix = "") { std::cout << prefix << d[0] << operation1 << d[1] << operation2 << d[2] << operation3 << d[3] << suffix << std::endl; } int main() { std::mt19937_64 randomGenerator; std::uniform_int_distribution<Digit> digitDistro{1, maximumDigit}; for(int trial{10}; trial; --trial) { for(Digit& digit : d) { digit = digitDistro(randomGenerator); std::cout << digit << " "; } std::cout << std::endl; std::sort(d.begin(), d.end()); if(std::accumulate(d.cbegin(), d.cend(), 0) == gameGoal) printTrivialOperation(" + "); if(std::accumulate(d.cbegin(), d.cend(), 1, std::multiplies<Digit>{}) == gameGoal) printTrivialOperation(" * "); do { if(d[0] + d[1] + d[2] - d[3] == gameGoal) printOperation("", " + ", " + ", " - "); if(d[0] * d[1] + d[2] + d[3] == gameGoal) printOperation("", " * ", " + ", " + "); if(d[0] * (d[1] + d[2]) + d[3] == gameGoal) printOperation("", " * ( ", " + ", " ) + "); if(d[0] * (d[1] + d[2] + d[3]) == gameGoal) printOperation("", " * ( ", " + ", " + ", " )"); if((d[0] * d[1] * d[2]) + d[3] == gameGoal) printOperation("( ", " * ", " * ", " ) + "); if(d[0] * d[1] * (d[2] + d[3]) == gameGoal) printOperation("( ", " * ", " * ( ", " + ", " )"); if((d[0] * d[1]) + (d[2] * d[3]) == gameGoal) printOperation("( ", " * ", " ) + ( ", " * ", " )"); if((d[0] * d[1] * d[2]) - d[3] == gameGoal) printOperation("( ", " * ", " * ", " ) - "); if(d[0] * d[1] * (d[2] - d[3]) == gameGoal) printOperation("( ", " * ", " * ( ", " - ", " )"); if((d[0] * d[1]) - (d[2] * d[3]) == gameGoal) printOperation("( ", " * ", " ) - ( ", " * ", " )"); if(d[0] * d[1] + d[2] - d[3] == gameGoal) printOperation("", " * ", " + ", " - "); if(d[0] * (d[1] + d[2]) - d[3] == gameGoal) printOperation("", " * ( ", " + ", " ) - "); if(d[0] * (d[1] - d[2]) + d[3] == gameGoal) printOperation("", " * ( ", " - ", " ) + "); if(d[0] * (d[1] + d[2] - d[3]) == gameGoal) printOperation("", " * ( ", " + ", " - ", " )"); if(d[0] * d[1] - (d[2] + d[3]) == gameGoal) printOperation("", " * ", " - ( ", " + ", " )"); if(d[0] * d[1] == (gameGoal - d[3]) * d[2]) printOperation("( ", " * ", " / ", " ) + "); if(((d[0] * d[1]) + d[2]) == gameGoal * d[3]) printOperation("(( ", " * ", " ) + ", " ) / "); if((d[0] + d[1]) * d[2] == gameGoal * d[3]) printOperation("(( ", " + ", " ) * ", " ) / "); if(d[0] * d[1] == gameGoal * (d[2] + d[3])) printOperation("( ", " * ", " ) / ( ", " + ", " )"); if(d[0] * d[1] == (gameGoal + d[3]) * d[2]) printOperation("( ", " * ", " / ", " ) - "); if(((d[0] * d[1]) - d[2]) == gameGoal * d[3]) printOperation("(( ", " * ", " ) - ", " ) / "); if((d[0] - d[1]) * d[2] == gameGoal * d[3]) printOperation("(( ", " - ", " ) * ", " ) / "); if(d[0] * d[1] == gameGoal * (d[2] - d[3])) printOperation("( ", " * ", " ) / ( ", " - ", " )"); if(d[0] * d[1] * d[2] == gameGoal * d[3]) printOperation("", " * ", " * ", " / "); if(d[0] * d[1] == gameGoal * d[2] * d[3]) printOperation("", " * ", " / ( ", " * ", " )"); if(d[0] * d[3] == gameGoal * (d[1] * d[3] - d[2])) printOperation("", " / ( ", " - ", " / ", " )"); if(d[0] * d[1] == gameGoal * d[2] * d[3]) printOperation("( ", " * ", " / ", " ) / ", ""); } while(std::next_permutation(d.begin(), d.end())); } return 0; }
import java.util.*; public class Game24Player { final String[] patterns = {"nnonnoo", "nnonono", "nnnoono", "nnnonoo", "nnnnooo"}; final String ops = "+-*/^"; String solution; List<Integer> digits; public static void main(String[] args) { new Game24Player().play(); } void play() { digits = getSolvableDigits(); Scanner in = new Scanner(System.in); while (true) { System.out.print("Make 24 using these digits: "); System.out.println(digits); System.out.println("(Enter 'q' to quit, 's' for a solution)"); System.out.print("> "); String line = in.nextLine(); if (line.equalsIgnoreCase("q")) { System.out.println("\nThanks for playing"); return; } if (line.equalsIgnoreCase("s")) { System.out.println(solution); digits = getSolvableDigits(); continue; } char[] entry = line.replaceAll("[^*+-/)(\\d]", "").toCharArray(); try { validate(entry); if (evaluate(infixToPostfix(entry))) { System.out.println("\nCorrect! Want to try another? "); digits = getSolvableDigits(); } else { System.out.println("\nNot correct."); } } catch (Exception e) { System.out.printf("%n%s Try again.%n", e.getMessage()); } } } void validate(char[] input) throws Exception { int total1 = 0, parens = 0, opsCount = 0; for (char c : input) { if (Character.isDigit(c)) total1 += 1 << (c - '0') * 4; else if (c == '(') parens++; else if (c == ')') parens--; else if (ops.indexOf(c) != -1) opsCount++; if (parens < 0) throw new Exception("Parentheses mismatch."); } if (parens != 0) throw new Exception("Parentheses mismatch."); if (opsCount != 3) throw new Exception("Wrong number of operators."); int total2 = 0; for (int d : digits) total2 += 1 << d * 4; if (total1 != total2) throw new Exception("Not the same digits."); } boolean evaluate(char[] line) throws Exception { Stack<Float> s = new Stack<>(); try { for (char c : line) { if ('0' <= c && c <= '9') s.push((float) c - '0'); else s.push(applyOperator(s.pop(), s.pop(), c)); } } catch (EmptyStackException e) { throw new Exception("Invalid entry."); } return (Math.abs(24 - s.peek()) < 0.001F); } float applyOperator(float a, float b, char c) { switch (c) { case '+': return a + b; case '-': return b - a; case '*': return a * b; case '/': return b / a; default: return Float.NaN; } } List<Integer> randomDigits() { Random r = new Random(); List<Integer> result = new ArrayList<>(4); for (int i = 0; i < 4; i++) result.add(r.nextInt(9) + 1); return result; } List<Integer> getSolvableDigits() { List<Integer> result; do { result = randomDigits(); } while (!isSolvable(result)); return result; } boolean isSolvable(List<Integer> digits) { Set<List<Integer>> dPerms = new HashSet<>(4 * 3 * 2); permute(digits, dPerms, 0); int total = 4 * 4 * 4; List<List<Integer>> oPerms = new ArrayList<>(total); permuteOperators(oPerms, 4, total); StringBuilder sb = new StringBuilder(4 + 3); for (String pattern : patterns) { char[] patternChars = pattern.toCharArray(); for (List<Integer> dig : dPerms) { for (List<Integer> opr : oPerms) { int i = 0, j = 0; for (char c : patternChars) { if (c == 'n') sb.append(dig.get(i++)); else sb.append(ops.charAt(opr.get(j++))); } String candidate = sb.toString(); try { if (evaluate(candidate.toCharArray())) { solution = postfixToInfix(candidate); return true; } } catch (Exception ignored) { } sb.setLength(0); } } } return false; } String postfixToInfix(String postfix) { class Expression { String op, ex; int prec = 3; Expression(String e) { ex = e; } Expression(String e1, String e2, String o) { ex = String.format("%s %s %s", e1, o, e2); op = o; prec = ops.indexOf(o) / 2; } } Stack<Expression> expr = new Stack<>(); for (char c : postfix.toCharArray()) { int idx = ops.indexOf(c); if (idx != -1) { Expression r = expr.pop(); Expression l = expr.pop(); int opPrec = idx / 2; if (l.prec < opPrec) l.ex = '(' + l.ex + ')'; if (r.prec <= opPrec) r.ex = '(' + r.ex + ')'; expr.push(new Expression(l.ex, r.ex, "" + c)); } else { expr.push(new Expression("" + c)); } } return expr.peek().ex; } char[] infixToPostfix(char[] infix) throws Exception { StringBuilder sb = new StringBuilder(); Stack<Integer> s = new Stack<>(); try { for (char c : infix) { int idx = ops.indexOf(c); if (idx != -1) { if (s.isEmpty()) s.push(idx); else { while (!s.isEmpty()) { int prec2 = s.peek() / 2; int prec1 = idx / 2; if (prec2 >= prec1) sb.append(ops.charAt(s.pop())); else break; } s.push(idx); } } else if (c == '(') { s.push(-2); } else if (c == ')') { while (s.peek() != -2) sb.append(ops.charAt(s.pop())); s.pop(); } else { sb.append(c); } } while (!s.isEmpty()) sb.append(ops.charAt(s.pop())); } catch (EmptyStackException e) { throw new Exception("Invalid entry."); } return sb.toString().toCharArray(); } void permute(List<Integer> lst, Set<List<Integer>> res, int k) { for (int i = k; i < lst.size(); i++) { Collections.swap(lst, i, k); permute(lst, res, k + 1); Collections.swap(lst, k, i); } if (k == lst.size()) res.add(new ArrayList<>(lst)); } void permuteOperators(List<List<Integer>> res, int n, int total) { for (int i = 0, npow = n * n; i < total; i++) res.add(Arrays.asList((i / npow), (i % npow) / n, i % n)); } }
Convert this C++ block to Java, preserving its control flow and logic.
#include <iostream> #include <chrono> #include <atomic> #include <mutex> #include <random> #include <thread> std::mutex cout_lock; class Latch { std::atomic<int> semafor; public: Latch(int limit) : semafor(limit) {} void wait() { semafor.fetch_sub(1); while(semafor.load() > 0) std::this_thread::yield(); } }; struct Worker { static void do_work(int how_long, Latch& barrier, std::string name) { std::this_thread::sleep_for(std::chrono::milliseconds(how_long)); { std::lock_guard<std::mutex> lock(cout_lock); std::cout << "Worker " << name << " finished work\n"; } barrier.wait(); { std::lock_guard<std::mutex> lock(cout_lock); std::cout << "Worker " << name << " finished assembly\n"; } } }; int main() { Latch latch(5); std::mt19937 rng(std::random_device{}()); std::uniform_int_distribution<> dist(300, 3000); std::thread threads[] { std::thread(&Worker::do_work, dist(rng), std::ref(latch), "John"), std::thread{&Worker::do_work, dist(rng), std::ref(latch), "Henry"}, std::thread{&Worker::do_work, dist(rng), std::ref(latch), "Smith"}, std::thread{&Worker::do_work, dist(rng), std::ref(latch), "Jane"}, std::thread{&Worker::do_work, dist(rng), std::ref(latch), "Mary"}, }; for(auto& t: threads) t.join(); std::cout << "Assembly is finished"; }
import java.util.Scanner; import java.util.Random; public class CheckpointSync{ public static void main(String[] args){ System.out.print("Enter number of workers to use: "); Scanner in = new Scanner(System.in); Worker.nWorkers = in.nextInt(); System.out.print("Enter number of tasks to complete:"); runTasks(in.nextInt()); } private static void runTasks(int nTasks){ for(int i = 0; i < nTasks; i++){ System.out.println("Starting task number " + (i+1) + "."); runThreads(); Worker.checkpoint(); } } private static void runThreads(){ for(int i = 0; i < Worker.nWorkers; i ++){ new Thread(new Worker(i+1)).start(); } } public static class Worker implements Runnable{ public Worker(int threadID){ this.threadID = threadID; } public void run(){ work(); } private synchronized void work(){ try { int workTime = rgen.nextInt(900) + 100; System.out.println("Worker " + threadID + " will work for " + workTime + " msec."); Thread.sleep(workTime); nFinished++; System.out.println("Worker " + threadID + " is ready"); } catch (InterruptedException e) { System.err.println("Error: thread execution interrupted"); e.printStackTrace(); } } public static synchronized void checkpoint(){ while(nFinished != nWorkers){ try { Thread.sleep(10); } catch (InterruptedException e) { System.err.println("Error: thread execution interrupted"); e.printStackTrace(); } } nFinished = 0; } private int threadID; private static Random rgen = new Random(); private static int nFinished = 0; public static int nWorkers = 0; } }
Change the following C++ code into Java without altering its purpose.
#include <iostream> #include <chrono> #include <atomic> #include <mutex> #include <random> #include <thread> std::mutex cout_lock; class Latch { std::atomic<int> semafor; public: Latch(int limit) : semafor(limit) {} void wait() { semafor.fetch_sub(1); while(semafor.load() > 0) std::this_thread::yield(); } }; struct Worker { static void do_work(int how_long, Latch& barrier, std::string name) { std::this_thread::sleep_for(std::chrono::milliseconds(how_long)); { std::lock_guard<std::mutex> lock(cout_lock); std::cout << "Worker " << name << " finished work\n"; } barrier.wait(); { std::lock_guard<std::mutex> lock(cout_lock); std::cout << "Worker " << name << " finished assembly\n"; } } }; int main() { Latch latch(5); std::mt19937 rng(std::random_device{}()); std::uniform_int_distribution<> dist(300, 3000); std::thread threads[] { std::thread(&Worker::do_work, dist(rng), std::ref(latch), "John"), std::thread{&Worker::do_work, dist(rng), std::ref(latch), "Henry"}, std::thread{&Worker::do_work, dist(rng), std::ref(latch), "Smith"}, std::thread{&Worker::do_work, dist(rng), std::ref(latch), "Jane"}, std::thread{&Worker::do_work, dist(rng), std::ref(latch), "Mary"}, }; for(auto& t: threads) t.join(); std::cout << "Assembly is finished"; }
import java.util.Scanner; import java.util.Random; public class CheckpointSync{ public static void main(String[] args){ System.out.print("Enter number of workers to use: "); Scanner in = new Scanner(System.in); Worker.nWorkers = in.nextInt(); System.out.print("Enter number of tasks to complete:"); runTasks(in.nextInt()); } private static void runTasks(int nTasks){ for(int i = 0; i < nTasks; i++){ System.out.println("Starting task number " + (i+1) + "."); runThreads(); Worker.checkpoint(); } } private static void runThreads(){ for(int i = 0; i < Worker.nWorkers; i ++){ new Thread(new Worker(i+1)).start(); } } public static class Worker implements Runnable{ public Worker(int threadID){ this.threadID = threadID; } public void run(){ work(); } private synchronized void work(){ try { int workTime = rgen.nextInt(900) + 100; System.out.println("Worker " + threadID + " will work for " + workTime + " msec."); Thread.sleep(workTime); nFinished++; System.out.println("Worker " + threadID + " is ready"); } catch (InterruptedException e) { System.err.println("Error: thread execution interrupted"); e.printStackTrace(); } } public static synchronized void checkpoint(){ while(nFinished != nWorkers){ try { Thread.sleep(10); } catch (InterruptedException e) { System.err.println("Error: thread execution interrupted"); e.printStackTrace(); } } nFinished = 0; } private int threadID; private static Random rgen = new Random(); private static int nFinished = 0; public static int nWorkers = 0; } }
Produce a language-to-language conversion: from C++ to Java, same semantics.
#include <iomanip> #include <iostream> #include <vector> std::ostream &operator<<(std::ostream &os, const std::vector<uint8_t> &v) { auto it = v.cbegin(); auto end = v.cend(); os << "[ "; if (it != end) { os << std::setfill('0') << std::setw(2) << (uint32_t)*it; it = std::next(it); } while (it != end) { os << ' ' << std::setfill('0') << std::setw(2) << (uint32_t)*it; it = std::next(it); } return os << " ]"; } std::vector<uint8_t> to_seq(uint64_t x) { int i; for (i = 9; i > 0; i--) { if (x & 127ULL << i * 7) { break; } } std::vector<uint8_t> out; for (int j = 0; j <= i; j++) { out.push_back(((x >> ((i - j) * 7)) & 127) | 128); } out[i] ^= 128; return out; } uint64_t from_seq(const std::vector<uint8_t> &seq) { uint64_t r = 0; for (auto b : seq) { r = (r << 7) | (b & 127); } return r; } int main() { std::vector<uint64_t> src{ 0x7f, 0x4000, 0, 0x3ffffe, 0x1fffff, 0x200000, 0x3311a1234df31413ULL }; for (auto x : src) { auto s = to_seq(x); std::cout << std::hex; std::cout << "seq from " << x << ' ' << s << " back: " << from_seq(s) << '\n'; std::cout << std::dec; } return 0; }
public class VLQCode { public static byte[] encode(long n) { int numRelevantBits = 64 - Long.numberOfLeadingZeros(n); int numBytes = (numRelevantBits + 6) / 7; if (numBytes == 0) numBytes = 1; byte[] output = new byte[numBytes]; for (int i = numBytes - 1; i >= 0; i--) { int curByte = (int)(n & 0x7F); if (i != (numBytes - 1)) curByte |= 0x80; output[i] = (byte)curByte; n >>>= 7; } return output; } public static long decode(byte[] b) { long n = 0; for (int i = 0; i < b.length; i++) { int curByte = b[i] & 0xFF; n = (n << 7) | (curByte & 0x7F); if ((curByte & 0x80) == 0) break; } return n; } public static String byteArrayToString(byte[] b) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < b.length; i++) { if (i > 0) sb.append(", "); String s = Integer.toHexString(b[i] & 0xFF); if (s.length() < 2) s = "0" + s; sb.append(s); } return sb.toString(); } public static void main(String[] args) { long[] testNumbers = { 2097152, 2097151, 1, 127, 128, 589723405834L }; for (long n : testNumbers) { byte[] encoded = encode(n); long decoded = decode(encoded); System.out.println("Original input=" + n + ", encoded = [" + byteArrayToString(encoded) + "], decoded=" + decoded + ", " + ((n == decoded) ? "OK" : "FAIL")); } } }
Convert this C++ block to Java, preserving its control flow and logic.
#include <cstdlib> #include <fstream> #include <iomanip> #include <iostream> #include <sstream> #include <vector> #include <openssl/sha.h> class sha256_exception : public std::exception { public: const char* what() const noexcept override { return "SHA-256 error"; } }; class sha256 { public: sha256() { reset(); } sha256(const sha256&) = delete; sha256& operator=(const sha256&) = delete; void reset() { if (SHA256_Init(&context_) == 0) throw sha256_exception(); } void update(const void* data, size_t length) { if (SHA256_Update(&context_, data, length) == 0) throw sha256_exception(); } std::vector<unsigned char> digest() { std::vector<unsigned char> digest(SHA256_DIGEST_LENGTH); if (SHA256_Final(digest.data(), &context_) == 0) throw sha256_exception(); return digest; } private: SHA256_CTX context_; }; std::string digest_to_string(const std::vector<unsigned char>& digest) { std::ostringstream out; out << std::hex << std::setfill('0'); for (size_t i = 0; i < digest.size(); ++i) out << std::setw(2) << static_cast<int>(digest[i]); return out.str(); } std::vector<unsigned char> sha256_merkle_tree(std::istream& in, size_t block_size) { std::vector<std::vector<unsigned char>> hashes; std::vector<char> buffer(block_size); sha256 md; while (in) { in.read(buffer.data(), block_size); size_t bytes = in.gcount(); if (bytes == 0) break; md.reset(); md.update(buffer.data(), bytes); hashes.push_back(md.digest()); } if (hashes.empty()) return {}; size_t length = hashes.size(); while (length > 1) { size_t j = 0; for (size_t i = 0; i < length; i += 2, ++j) { auto& digest1 = hashes[i]; auto& digest_out = hashes[j]; if (i + 1 < length) { auto& digest2 = hashes[i + 1]; md.reset(); md.update(digest1.data(), digest1.size()); md.update(digest2.data(), digest2.size()); digest_out = md.digest(); } else { digest_out = digest1; } } length = j; } return hashes[0]; } int main(int argc, char** argv) { if (argc != 2) { std::cerr << "usage: " << argv[0] << " filename\n"; return EXIT_FAILURE; } std::ifstream in(argv[1], std::ios::binary); if (!in) { std::cerr << "Cannot open file " << argv[1] << ".\n"; return EXIT_FAILURE; } try { std::cout << digest_to_string(sha256_merkle_tree(in, 1024)) << '\n'; } catch (const std::exception& ex) { std::cerr << ex.what() << "\n"; return EXIT_FAILURE; } return EXIT_SUCCESS; }
import java.io.*; import java.security.*; import java.util.*; public class SHA256MerkleTree { public static void main(String[] args) { if (args.length != 1) { System.err.println("missing file argument"); System.exit(1); } try (InputStream in = new BufferedInputStream(new FileInputStream(args[0]))) { byte[] digest = sha256MerkleTree(in, 1024); if (digest != null) System.out.println(digestToString(digest)); } catch (Exception e) { e.printStackTrace(); } } private static String digestToString(byte[] digest) { StringBuilder result = new StringBuilder(); for (int i = 0; i < digest.length; ++i) result.append(String.format("%02x", digest[i])); return result.toString(); } private static byte[] sha256MerkleTree(InputStream in, int blockSize) throws Exception { byte[] buffer = new byte[blockSize]; int bytes; MessageDigest md = MessageDigest.getInstance("SHA-256"); List<byte[]> digests = new ArrayList<>(); while ((bytes = in.read(buffer)) > 0) { md.reset(); md.update(buffer, 0, bytes); digests.add(md.digest()); } int length = digests.size(); if (length == 0) return null; while (length > 1) { int j = 0; for (int i = 0; i < length; i += 2, ++j) { byte[] digest1 = digests.get(i); if (i + 1 < length) { byte[] digest2 = digests.get(i + 1); md.reset(); md.update(digest1); md.update(digest2); digests.set(j, md.digest()); } else { digests.set(j, digest1); } } length = j; } return digests.get(0); } }
Change the programming language of this snippet from C++ to Java without modifying what it does.
#include <algorithm> #include <string> #include <cctype> void str_toupper(std::string &str) { std::transform(str.begin(), str.end(), str.begin(), (int(*)(int)) std::toupper); } void str_tolower(std::string &str) { std::transform(str.begin(), str.end(), str.begin(), (int(*)(int)) std::tolower); }
String str = "alphaBETA"; System.out.println(str.toUpperCase()); System.out.println(str.toLowerCase()); System.out.println("äàâáçñßæεбế".toUpperCase()); System.out.println("ÄÀÂÁÇÑSSÆΕБẾ".toLowerCase());
Can you help me rewrite this code in Java instead of C++, keeping it the same logically?
#include <algorithm> #include <string> #include <cctype> void str_toupper(std::string &str) { std::transform(str.begin(), str.end(), str.begin(), (int(*)(int)) std::toupper); } void str_tolower(std::string &str) { std::transform(str.begin(), str.end(), str.begin(), (int(*)(int)) std::tolower); }
String str = "alphaBETA"; System.out.println(str.toUpperCase()); System.out.println(str.toLowerCase()); System.out.println("äàâáçñßæεбế".toUpperCase()); System.out.println("ÄÀÂÁÇÑSSÆΕБẾ".toLowerCase());
Port the provided C++ code into Java while preserving the original functionality.
#ifndef TASK_H #define TASK_H #include <QWidget> class QLabel ; class QLineEdit ; class QVBoxLayout ; class QHBoxLayout ; class EntryWidget : public QWidget { Q_OBJECT public : EntryWidget( QWidget *parent = 0 ) ; private : QHBoxLayout *upperpart , *lowerpart ; QVBoxLayout *entryLayout ; QLineEdit *stringinput ; QLineEdit *numberinput ; QLabel *stringlabel ; QLabel *numberlabel ; } ; #endif
import javax.swing.*; public class GetInputSwing { public static void main(String[] args) throws Exception { int number = Integer.parseInt( JOptionPane.showInputDialog ("Enter an Integer")); String string = JOptionPane.showInputDialog ("Enter a String"); } }
Maintain the same structure and functionality when rewriting this code in Java.
#ifndef TASK_H #define TASK_H #include <QWidget> class QLabel ; class QLineEdit ; class QVBoxLayout ; class QHBoxLayout ; class EntryWidget : public QWidget { Q_OBJECT public : EntryWidget( QWidget *parent = 0 ) ; private : QHBoxLayout *upperpart , *lowerpart ; QVBoxLayout *entryLayout ; QLineEdit *stringinput ; QLineEdit *numberinput ; QLabel *stringlabel ; QLabel *numberlabel ; } ; #endif
import javax.swing.*; public class GetInputSwing { public static void main(String[] args) throws Exception { int number = Integer.parseInt( JOptionPane.showInputDialog ("Enter an Integer")); String string = JOptionPane.showInputDialog ("Enter a String"); } }
Produce a functionally identical Java code for the snippet given in C++.
#include <fstream> #include <iostream> #include <vector> constexpr double sqrt3_2 = 0.86602540378444; struct point { double x; double y; }; std::vector<point> sierpinski_arrowhead_next(const std::vector<point>& points) { size_t size = points.size(); std::vector<point> output(3*(size - 1) + 1); double x0, y0, x1, y1; size_t j = 0; for (size_t i = 0; i + 1 < size; ++i, j += 3) { x0 = points[i].x; y0 = points[i].y; x1 = points[i + 1].x; y1 = points[i + 1].y; double dx = x1 - x0; output[j] = {x0, y0}; if (y0 == y1) { double d = dx * sqrt3_2/2; if (d < 0) d = -d; output[j + 1] = {x0 + dx/4, y0 - d}; output[j + 2] = {x1 - dx/4, y0 - d}; } else if (y1 < y0) { output[j + 1] = {x1, y0}; output[j + 2] = {x1 + dx/2, (y0 + y1)/2}; } else { output[j + 1] = {x0 - dx/2, (y0 + y1)/2}; output[j + 2] = {x0, y1}; } } output[j] = {x1, y1}; return output; } void write_sierpinski_arrowhead(std::ostream& out, int size, int iterations) { out << "<svg xmlns='http: << size << "' height='" << size << "'>\n"; out << "<rect width='100%' height='100%' fill='white'/>\n"; out << "<path stroke-width='1' stroke='black' fill='none' d='"; const double margin = 20.0; const double side = size - 2.0 * margin; const double x = margin; const double y = 0.5 * size + 0.5 * sqrt3_2 * side; std::vector<point> points{{x, y}, {x + side, y}}; for (int i = 0; i < iterations; ++i) points = sierpinski_arrowhead_next(points); for (size_t i = 0, n = points.size(); i < n; ++i) out << (i == 0 ? "M" : "L") << points[i].x << ',' << points[i].y << '\n'; out << "'/>\n</svg>\n"; } int main() { std::ofstream out("sierpinski_arrowhead.svg"); if (!out) { std::cerr << "Cannot open output file\n"; return EXIT_FAILURE; } write_sierpinski_arrowhead(out, 600, 8); return EXIT_SUCCESS; }
final PVector t = new PVector(20, 30, 60); void setup() { size(450, 400); noLoop(); background(0, 0, 200); stroke(-1); sc(7, 400, -60, t); } PVector sc(int o, float l, final int a, final PVector s) { if (o > 0) { sc(--o, l *= .5, -a, s).z += a; sc(o, l, a, s).z += a; sc(o, l, -a, s); } else line(s.x, s.y, s.x += cos(radians(s.z)) * l, s.y += sin(radians(s.z)) * l); return s; }
Ensure the translated Java code behaves exactly like the original C++ snippet.
#include <iostream> #include <fstream> #include <string> #include <vector> #include <iomanip> #include <boost/lexical_cast.hpp> #include <boost/algorithm/string.hpp> using std::cout; using std::endl; const int NumFlags = 24; int main() { std::fstream file("readings.txt"); int badCount = 0; std::string badDate; int badCountMax = 0; while(true) { std::string line; getline(file, line); if(!file.good()) break; std::vector<std::string> tokens; boost::algorithm::split(tokens, line, boost::is_space()); if(tokens.size() != NumFlags * 2 + 1) { cout << "Bad input file." << endl; return 0; } double total = 0.0; int accepted = 0; for(size_t i = 1; i < tokens.size(); i += 2) { double val = boost::lexical_cast<double>(tokens[i]); int flag = boost::lexical_cast<int>(tokens[i+1]); if(flag > 0) { total += val; ++accepted; badCount = 0; } else { ++badCount; if(badCount > badCountMax) { badCountMax = badCount; badDate = tokens[0]; } } } cout << tokens[0]; cout << " Reject: " << std::setw(2) << (NumFlags - accepted); cout << " Accept: " << std::setw(2) << accepted; cout << " Average: " << std::setprecision(5) << total / accepted << endl; } cout << endl; cout << "Maximum number of consecutive bad readings is " << badCountMax << endl; cout << "Ends on date " << badDate << endl; }
import java.io.File; import java.util.*; import static java.lang.System.out; public class TextProcessing1 { public static void main(String[] args) throws Exception { Locale.setDefault(new Locale("en", "US")); Metrics metrics = new Metrics(); int dataGap = 0; String gapBeginDate = null; try (Scanner lines = new Scanner(new File("readings.txt"))) { while (lines.hasNextLine()) { double lineTotal = 0.0; int linePairs = 0; int lineInvalid = 0; String lineDate; try (Scanner line = new Scanner(lines.nextLine())) { lineDate = line.next(); while (line.hasNext()) { final double value = line.nextDouble(); if (line.nextInt() <= 0) { if (dataGap == 0) gapBeginDate = lineDate; dataGap++; lineInvalid++; continue; } lineTotal += value; linePairs++; metrics.addDataGap(dataGap, gapBeginDate, lineDate); dataGap = 0; } } metrics.addLine(lineTotal, linePairs); metrics.lineResult(lineDate, lineInvalid, linePairs, lineTotal); } metrics.report(); } } private static class Metrics { private List<String[]> gapDates; private int maxDataGap = -1; private double total; private int pairs; private int lineResultCount; void addLine(double tot, double prs) { total += tot; pairs += prs; } void addDataGap(int gap, String begin, String end) { if (gap > 0 && gap >= maxDataGap) { if (gap > maxDataGap) { maxDataGap = gap; gapDates = new ArrayList<>(); } gapDates.add(new String[]{begin, end}); } } void lineResult(String date, int invalid, int prs, double tot) { if (lineResultCount >= 3) return; out.printf("%10s out: %2d in: %2d tot: %10.3f avg: %10.3f%n", date, invalid, prs, tot, (prs > 0) ? tot / prs : 0.0); lineResultCount++; } void report() { out.printf("%ntotal = %10.3f%n", total); out.printf("readings = %6d%n", pairs); out.printf("average = %010.3f%n", total / pairs); out.printf("%nmaximum run(s) of %d invalid measurements: %n", maxDataGap); for (String[] dates : gapDates) out.printf("begins at %s and ends at %s%n", dates[0], dates[1]); } } }
Write the same code in Java as shown below in C++.
#include <string> #include <iostream> #include "Poco/MD5Engine.h" #include "Poco/DigestStream.h" using Poco::DigestEngine ; using Poco::MD5Engine ; using Poco::DigestOutputStream ; int main( ) { std::string myphrase ( "The quick brown fox jumped over the lazy dog's back" ) ; MD5Engine md5 ; DigestOutputStream outstr( md5 ) ; outstr << myphrase ; outstr.flush( ) ; const DigestEngine::Digest& digest = md5.digest( ) ; std::cout << myphrase << " as a MD5 digest :\n" << DigestEngine::digestToHex( digest ) << " !" << std::endl ; return 0 ; }
import java.nio.charset.StandardCharsets; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class Digester { public static void main(String[] args) { System.out.println(hexDigest("Rosetta code", "MD5")); } static String hexDigest(String str, String digestName) { try { MessageDigest md = MessageDigest.getInstance(digestName); byte[] digest = md.digest(str.getBytes(StandardCharsets.UTF_8)); char[] hex = new char[digest.length * 2]; for (int i = 0; i < digest.length; i++) { hex[2 * i] = "0123456789abcdef".charAt((digest[i] & 0xf0) >> 4); hex[2 * i + 1] = "0123456789abcdef".charAt(digest[i] & 0x0f); } return new String(hex); } catch (NoSuchAlgorithmException e) { throw new IllegalStateException(e); } } }
Can you help me rewrite this code in Java instead of C++, keeping it the same logically?
#include <cstdint> #include <iostream> #include <string> using integer = uint64_t; integer divisor_sum(integer n) { integer total = 1, power = 2; for (; n % 2 == 0; power *= 2, n /= 2) total += power; for (integer p = 3; p * p <= n; p += 2) { integer sum = 1; for (power = p; n % p == 0; power *= p, n /= p) sum += power; total *= sum; } if (n > 1) total *= n + 1; return total; } void classify_aliquot_sequence(integer n) { constexpr int limit = 16; integer terms[limit]; terms[0] = n; std::string classification("non-terminating"); int length = 1; for (int i = 1; i < limit; ++i) { ++length; terms[i] = divisor_sum(terms[i - 1]) - terms[i - 1]; if (terms[i] == n) { classification = (i == 1 ? "perfect" : (i == 2 ? "amicable" : "sociable")); break; } int j = 1; for (; j < i; ++j) { if (terms[i] == terms[i - j]) break; } if (j < i) { classification = (j == 1 ? "aspiring" : "cyclic"); break; } if (terms[i] == 0) { classification = "terminating"; break; } } std::cout << n << ": " << classification << ", sequence: " << terms[0]; for (int i = 1; i < length && terms[i] != terms[i - 1]; ++i) std::cout << ' ' << terms[i]; std::cout << '\n'; } int main() { for (integer i = 1; i <= 10; ++i) classify_aliquot_sequence(i); for (integer i : {11, 12, 28, 496, 220, 1184, 12496, 1264460, 790, 909, 562, 1064, 1488}) classify_aliquot_sequence(i); classify_aliquot_sequence(15355717786080); classify_aliquot_sequence(153557177860800); return 0; }
import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.stream.LongStream; public class AliquotSequenceClassifications { private static Long properDivsSum(long n) { return LongStream.rangeClosed(1, (n + 1) / 2).filter(i -> n % i == 0 && n != i).sum(); } static boolean aliquot(long n, int maxLen, long maxTerm) { List<Long> s = new ArrayList<>(maxLen); s.add(n); long newN = n; while (s.size() <= maxLen && newN < maxTerm) { newN = properDivsSum(s.get(s.size() - 1)); if (s.contains(newN)) { if (s.get(0) == newN) { switch (s.size()) { case 1: return report("Perfect", s); case 2: return report("Amicable", s); default: return report("Sociable of length " + s.size(), s); } } else if (s.get(s.size() - 1) == newN) { return report("Aspiring", s); } else return report("Cyclic back to " + newN, s); } else { s.add(newN); if (newN == 0) return report("Terminating", s); } } return report("Non-terminating", s); } static boolean report(String msg, List<Long> result) { System.out.println(msg + ": " + result); return false; } public static void main(String[] args) { long[] arr = { 11, 12, 28, 496, 220, 1184, 12496, 1264460, 790, 909, 562, 1064, 1488}; LongStream.rangeClosed(1, 10).forEach(n -> aliquot(n, 16, 1L << 47)); System.out.println(); Arrays.stream(arr).forEach(n -> aliquot(n, 16, 1L << 47)); } }
Write a version of this C++ function in Java with identical behavior.
#include <cstdint> #include <iostream> #include <string> using integer = uint64_t; integer divisor_sum(integer n) { integer total = 1, power = 2; for (; n % 2 == 0; power *= 2, n /= 2) total += power; for (integer p = 3; p * p <= n; p += 2) { integer sum = 1; for (power = p; n % p == 0; power *= p, n /= p) sum += power; total *= sum; } if (n > 1) total *= n + 1; return total; } void classify_aliquot_sequence(integer n) { constexpr int limit = 16; integer terms[limit]; terms[0] = n; std::string classification("non-terminating"); int length = 1; for (int i = 1; i < limit; ++i) { ++length; terms[i] = divisor_sum(terms[i - 1]) - terms[i - 1]; if (terms[i] == n) { classification = (i == 1 ? "perfect" : (i == 2 ? "amicable" : "sociable")); break; } int j = 1; for (; j < i; ++j) { if (terms[i] == terms[i - j]) break; } if (j < i) { classification = (j == 1 ? "aspiring" : "cyclic"); break; } if (terms[i] == 0) { classification = "terminating"; break; } } std::cout << n << ": " << classification << ", sequence: " << terms[0]; for (int i = 1; i < length && terms[i] != terms[i - 1]; ++i) std::cout << ' ' << terms[i]; std::cout << '\n'; } int main() { for (integer i = 1; i <= 10; ++i) classify_aliquot_sequence(i); for (integer i : {11, 12, 28, 496, 220, 1184, 12496, 1264460, 790, 909, 562, 1064, 1488}) classify_aliquot_sequence(i); classify_aliquot_sequence(15355717786080); classify_aliquot_sequence(153557177860800); return 0; }
import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.stream.LongStream; public class AliquotSequenceClassifications { private static Long properDivsSum(long n) { return LongStream.rangeClosed(1, (n + 1) / 2).filter(i -> n % i == 0 && n != i).sum(); } static boolean aliquot(long n, int maxLen, long maxTerm) { List<Long> s = new ArrayList<>(maxLen); s.add(n); long newN = n; while (s.size() <= maxLen && newN < maxTerm) { newN = properDivsSum(s.get(s.size() - 1)); if (s.contains(newN)) { if (s.get(0) == newN) { switch (s.size()) { case 1: return report("Perfect", s); case 2: return report("Amicable", s); default: return report("Sociable of length " + s.size(), s); } } else if (s.get(s.size() - 1) == newN) { return report("Aspiring", s); } else return report("Cyclic back to " + newN, s); } else { s.add(newN); if (newN == 0) return report("Terminating", s); } } return report("Non-terminating", s); } static boolean report(String msg, List<Long> result) { System.out.println(msg + ": " + result); return false; } public static void main(String[] args) { long[] arr = { 11, 12, 28, 496, 220, 1184, 12496, 1264460, 790, 909, 562, 1064, 1488}; LongStream.rangeClosed(1, 10).forEach(n -> aliquot(n, 16, 1L << 47)); System.out.println(); Arrays.stream(arr).forEach(n -> aliquot(n, 16, 1L << 47)); } }
Convert this C++ block to Java, preserving its control flow and logic.
#include <string> #include <iostream> #include <boost/date_time/local_time/local_time.hpp> #include <sstream> #include <boost/date_time/gregorian/gregorian.hpp> #include <vector> #include <boost/algorithm/string.hpp> #include <cstdlib> #include <locale> int main( ) { std::string datestring ("March 7 2009 7:30pm EST" ) ; std::vector<std::string> elements ; boost::split( elements , datestring , boost::is_any_of( " " ) ) ; std::string datepart = elements[ 0 ] + " " + "0" + elements[ 1 ] + " " + elements[ 2 ] ; std::string timepart = elements[ 3 ] ; std::string timezone = elements[ 4 ] ; const char meridians[ ] = { 'a' , 'p' } ; std::string::size_type found = timepart.find_first_of( meridians, 0 ) ; std::string twelve_hour ( timepart.substr( found , 1 ) ) ; timepart = timepart.substr( 0 , found ) ; elements.clear( ) ; boost::split( elements , timepart , boost::is_any_of ( ":" ) ) ; long hour = std::atol( (elements.begin( ))->c_str( ) ) ; if ( twelve_hour == "p" ) hour += 12 ; long minute = std::atol( ( elements.begin( ) + 1)->c_str( ) ) ; boost::local_time::tz_database tz_db ; tz_db.load_from_file( "/home/ulrich/internetpages/date_time_zonespec.csv" ) ; boost::local_time::time_zone_ptr dyc = tz_db.time_zone_from_region( "America/New_York" ) ; boost::gregorian::date_input_facet *f = new boost::gregorian::date_input_facet( "%B %d %Y" ) ; std::stringstream ss ; ss << datepart ; ss.imbue( std::locale( std::locale::classic( ) , f ) ) ; boost::gregorian::date d ; ss >> d ; boost::posix_time::time_duration td ( hour , minute , 0 ) ; boost::local_time::local_date_time lt ( d , td , dyc , boost::local_time::local_date_time::NOT_DATE_TIME_ON_ERROR ) ; std::cout << "local time: " << lt << '\n' ; ss.str( "" ) ; ss << lt ; boost::posix_time::time_duration td2 (12 , 0 , 0 , 0 ) ; boost::local_time::local_date_time ltlater = lt + td2 ; boost::gregorian::date_facet *f2 = new boost::gregorian::date_facet( "%B %d %Y , %R %Z" ) ; std::cout.imbue( std::locale( std::locale::classic( ) , f2 ) ) ; std::cout << "12 hours after " << ss.str( ) << " it is " << ltlater << " !\n" ; boost::local_time::time_zone_ptr bt = tz_db.time_zone_from_region( "Europe/Berlin" ) ; std::cout.imbue( std::locale( "de_DE.UTF-8" ) ) ; std::cout << "This corresponds to " << ltlater.local_time_in( bt ) << " in Berlin!\n" ; return 0 ; }
import java.time.*; import java.time.format.*; class Main { public static void main(String args[]) { String dateStr = "March 7 2009 7:30pm EST"; DateTimeFormatter df = new DateTimeFormatterBuilder() .parseCaseInsensitive() .appendPattern("MMMM d yyyy h:mma zzz") .toFormatter(); ZonedDateTime after12Hours = ZonedDateTime.parse(dateStr, df).plusHours(12); System.out.println("Date: " + dateStr); System.out.println("+12h: " + after12Hours.format(df)); ZonedDateTime after12HoursInCentralEuropeTime = after12Hours.withZoneSameInstant(ZoneId.of("CET")); System.out.println("+12h (in Central Europe): " + after12HoursInCentralEuropeTime.format(df)); } }
Convert the following code from C++ to Java, ensuring the logic remains intact.
#include <chrono> #include <iostream> #include <thread> #include <vector> int main(int argc, char* argv[]) { std::vector<std::thread> threads; for (int i = 1; i < argc; ++i) { threads.emplace_back([i, &argv]() { int arg = std::stoi(argv[i]); std::this_thread::sleep_for(std::chrono::seconds(arg)); std::cout << argv[i] << std::endl; }); } for (auto& thread : threads) { thread.join(); } }
import java.util.concurrent.CountDownLatch; public class SleepSort { public static void sleepSortAndPrint(int[] nums) { final CountDownLatch doneSignal = new CountDownLatch(nums.length); for (final int num : nums) { new Thread(new Runnable() { public void run() { doneSignal.countDown(); try { doneSignal.await(); Thread.sleep(num * 1000); System.out.println(num); } catch (InterruptedException e) { e.printStackTrace(); } } }).start(); } } public static void main(String[] args) { int[] nums = new int[args.length]; for (int i = 0; i < args.length; i++) nums[i] = Integer.parseInt(args[i]); sleepSortAndPrint(nums); } }
Rewrite this program in Java while keeping its functionality equivalent to the C++ version.
#include<cstdlib> #include<ctime> #include<iostream> using namespace std; int main() { int arr[10][10]; srand(time(NULL)); for(auto& row: arr) for(auto& col: row) col = rand() % 20 + 1; ([&](){ for(auto& row : arr) for(auto& col: row) { cout << col << endl; if(col == 20)return; } })(); return 0; }
import java.util.Random; public class NestedLoopTest { public static final Random gen = new Random(); public static void main(String[] args) { int[][] a = new int[10][10]; for (int i = 0; i < a.length; i++) for (int j = 0; j < a[i].length; j++) a[i][j] = gen.nextInt(20) + 1; Outer:for (int i = 0; i < a.length; i++) { for (int j = 0; j < a[i].length; j++) { System.out.print(" " + a[i][j]); if (a[i][j] == 20) break Outer; } System.out.println(); } System.out.println(); } }
Port the following code from C++ to Java with equivalent syntax and logic.
#include<cstdlib> #include<ctime> #include<iostream> using namespace std; int main() { int arr[10][10]; srand(time(NULL)); for(auto& row: arr) for(auto& col: row) col = rand() % 20 + 1; ([&](){ for(auto& row : arr) for(auto& col: row) { cout << col << endl; if(col == 20)return; } })(); return 0; }
import java.util.Random; public class NestedLoopTest { public static final Random gen = new Random(); public static void main(String[] args) { int[][] a = new int[10][10]; for (int i = 0; i < a.length; i++) for (int j = 0; j < a[i].length; j++) a[i][j] = gen.nextInt(20) + 1; Outer:for (int i = 0; i < a.length; i++) { for (int j = 0; j < a[i].length; j++) { System.out.print(" " + a[i][j]); if (a[i][j] == 20) break Outer; } System.out.println(); } System.out.println(); } }
Change the following C++ code into Java without altering its purpose.
#include <cmath> #include <iostream> #include <numeric> #include <tuple> #include <vector> using namespace std; auto CountTriplets(unsigned long long maxPerimeter) { unsigned long long totalCount = 0; unsigned long long primitveCount = 0; auto max_M = (unsigned long long)sqrt(maxPerimeter/2) + 1; for(unsigned long long m = 2; m < max_M; ++m) { for(unsigned long long n = 1 + m % 2; n < m; n+=2) { if(gcd(m,n) != 1) { continue; } auto a = m * m - n * n; auto b = 2 * m * n; auto c = m * m + n * n; auto perimeter = a + b + c; if(perimeter <= maxPerimeter) { primitveCount++; totalCount+= maxPerimeter / perimeter; } } } return tuple(totalCount, primitveCount); } int main() { vector<unsigned long long> inputs{100, 1000, 10'000, 100'000, 1000'000, 10'000'000, 100'000'000, 1000'000'000, 10'000'000'000}; for(auto maxPerimeter : inputs) { auto [total, primitive] = CountTriplets(maxPerimeter); cout << "\nMax Perimeter: " << maxPerimeter << ", Total: " << total << ", Primitive: " << primitive ; } }
import java.math.BigInteger; import static java.math.BigInteger.ONE; public class PythTrip{ public static void main(String[] args){ long tripCount = 0, primCount = 0; BigInteger periLimit = BigInteger.valueOf(100), peri2 = periLimit.divide(BigInteger.valueOf(2)), peri3 = periLimit.divide(BigInteger.valueOf(3)); for(BigInteger a = ONE; a.compareTo(peri3) < 0; a = a.add(ONE)){ BigInteger aa = a.multiply(a); for(BigInteger b = a.add(ONE); b.compareTo(peri2) < 0; b = b.add(ONE)){ BigInteger bb = b.multiply(b); BigInteger ab = a.add(b); BigInteger aabb = aa.add(bb); for(BigInteger c = b.add(ONE); c.compareTo(peri2) < 0; c = c.add(ONE)){ int compare = aabb.compareTo(c.multiply(c)); if(ab.add(c).compareTo(periLimit) > 0){ break; } if(compare < 0){ break; }else if (compare == 0){ tripCount++; System.out.print(a + ", " + b + ", " + c); if(a.gcd(b).equals(ONE)){ System.out.print(" primitive"); primCount++; } System.out.println(); } } } } System.out.println("Up to a perimeter of " + periLimit + ", there are " + tripCount + " triples, of which " + primCount + " are primitive."); } }
Write a version of this C++ function in Java with identical behavior.
#include <cmath> #include <iostream> #include <numeric> #include <tuple> #include <vector> using namespace std; auto CountTriplets(unsigned long long maxPerimeter) { unsigned long long totalCount = 0; unsigned long long primitveCount = 0; auto max_M = (unsigned long long)sqrt(maxPerimeter/2) + 1; for(unsigned long long m = 2; m < max_M; ++m) { for(unsigned long long n = 1 + m % 2; n < m; n+=2) { if(gcd(m,n) != 1) { continue; } auto a = m * m - n * n; auto b = 2 * m * n; auto c = m * m + n * n; auto perimeter = a + b + c; if(perimeter <= maxPerimeter) { primitveCount++; totalCount+= maxPerimeter / perimeter; } } } return tuple(totalCount, primitveCount); } int main() { vector<unsigned long long> inputs{100, 1000, 10'000, 100'000, 1000'000, 10'000'000, 100'000'000, 1000'000'000, 10'000'000'000}; for(auto maxPerimeter : inputs) { auto [total, primitive] = CountTriplets(maxPerimeter); cout << "\nMax Perimeter: " << maxPerimeter << ", Total: " << total << ", Primitive: " << primitive ; } }
import java.math.BigInteger; import static java.math.BigInteger.ONE; public class PythTrip{ public static void main(String[] args){ long tripCount = 0, primCount = 0; BigInteger periLimit = BigInteger.valueOf(100), peri2 = periLimit.divide(BigInteger.valueOf(2)), peri3 = periLimit.divide(BigInteger.valueOf(3)); for(BigInteger a = ONE; a.compareTo(peri3) < 0; a = a.add(ONE)){ BigInteger aa = a.multiply(a); for(BigInteger b = a.add(ONE); b.compareTo(peri2) < 0; b = b.add(ONE)){ BigInteger bb = b.multiply(b); BigInteger ab = a.add(b); BigInteger aabb = aa.add(bb); for(BigInteger c = b.add(ONE); c.compareTo(peri2) < 0; c = c.add(ONE)){ int compare = aabb.compareTo(c.multiply(c)); if(ab.add(c).compareTo(periLimit) > 0){ break; } if(compare < 0){ break; }else if (compare == 0){ tripCount++; System.out.print(a + ", " + b + ", " + c); if(a.gcd(b).equals(ONE)){ System.out.print(" primitive"); primCount++; } System.out.println(); } } } } System.out.println("Up to a perimeter of " + periLimit + ", there are " + tripCount + " triples, of which " + primCount + " are primitive."); } }
Write a version of this C++ function in Java with identical behavior.
#include <set> #include <iostream> using namespace std; int main() { typedef set<int> TySet; int data[] = {1, 2, 3, 2, 3, 4}; TySet unique_set(data, data + 6); cout << "Set items:" << endl; for (TySet::iterator iter = unique_set.begin(); iter != unique_set.end(); iter++) cout << *iter << " "; cout << endl; }
module RetainUniqueValues { @Inject Console console; void run() { Int[] array = [1, 2, 3, 2, 1, 2, 3, 4, 5, 3, 2, 1]; array = array.distinct().toArray(); console.print($"result={array}"); } }
Preserve the algorithm and functionality while converting the code from C++ to Java.
#include <iostream> #include <sstream> #include <string> std::string lookandsay(const std::string& s) { std::ostringstream r; for (std::size_t i = 0; i != s.length();) { auto new_i = s.find_first_not_of(s[i], i + 1); if (new_i == std::string::npos) new_i = s.length(); r << new_i - i << s[i]; i = new_i; } return r.str(); } int main() { std::string laf = "1"; std::cout << laf << '\n'; for (int i = 0; i < 10; ++i) { laf = lookandsay(laf); std::cout << laf << '\n'; } }
public static String lookandsay(String number){ StringBuilder result= new StringBuilder(); char repeat= number.charAt(0); number= number.substring(1) + " "; int times= 1; for(char actual: number.toCharArray()){ if(actual != repeat){ result.append(times + "" + repeat); times= 1; repeat= actual; }else{ times+= 1; } } return result.toString(); }
Keep all operations the same but rewrite the snippet in Java.
#include <stack>
import java.util.Stack; public class StackTest { public static void main( final String[] args ) { final Stack<String> stack = new Stack<String>(); System.out.println( "New stack empty? " + stack.empty() ); stack.push( "There can be only one" ); System.out.println( "Pushed stack empty? " + stack.empty() ); System.out.println( "Popped single entry: " + stack.pop() ); stack.push( "First" ); stack.push( "Second" ); System.out.println( "Popped entry should be second: " + stack.pop() ); stack.pop(); stack.pop(); } }
Please provide an equivalent version of this C++ code in Java.
#include <stack>
import java.util.Stack; public class StackTest { public static void main( final String[] args ) { final Stack<String> stack = new Stack<String>(); System.out.println( "New stack empty? " + stack.empty() ); stack.push( "There can be only one" ); System.out.println( "Pushed stack empty? " + stack.empty() ); System.out.println( "Popped single entry: " + stack.pop() ); stack.push( "First" ); stack.push( "Second" ); System.out.println( "Popped entry should be second: " + stack.pop() ); stack.pop(); stack.pop(); } }
Produce a functionally identical Java code for the snippet given in C++.
#include <cassert> #include <iomanip> #include <iostream> #include <vector> class totient_calculator { public: explicit totient_calculator(int max) : totient_(max + 1) { for (int i = 1; i <= max; ++i) totient_[i] = i; for (int i = 2; i <= max; ++i) { if (totient_[i] < i) continue; for (int j = i; j <= max; j += i) totient_[j] -= totient_[j] / i; } } int totient(int n) const { assert (n >= 1 && n < totient_.size()); return totient_[n]; } bool is_prime(int n) const { return totient(n) == n - 1; } private: std::vector<int> totient_; }; int count_primes(const totient_calculator& tc, int min, int max) { int count = 0; for (int i = min; i <= max; ++i) { if (tc.is_prime(i)) ++count; } return count; } int main() { const int max = 10000000; totient_calculator tc(max); std::cout << " n totient prime?\n"; for (int i = 1; i <= 25; ++i) { std::cout << std::setw(2) << i << std::setw(9) << tc.totient(i) << std::setw(8) << (tc.is_prime(i) ? "yes" : "no") << '\n'; } for (int n = 100; n <= max; n *= 10) { std::cout << "Count of primes up to " << n << ": " << count_primes(tc, 1, n) << '\n'; } return 0; }
public class TotientFunction { public static void main(String[] args) { computePhi(); System.out.println("Compute and display phi for the first 25 integers."); System.out.printf("n Phi IsPrime%n"); for ( int n = 1 ; n <= 25 ; n++ ) { System.out.printf("%2d %2d %b%n", n, phi[n], (phi[n] == n-1)); } for ( int i = 2 ; i < 8 ; i++ ) { int max = (int) Math.pow(10, i); System.out.printf("The count of the primes up to %,10d = %d%n", max, countPrimes(1, max)); } } private static int countPrimes(int min, int max) { int count = 0; for ( int i = min ; i <= max ; i++ ) { if ( phi[i] == i-1 ) { count++; } } return count; } private static final int max = 10000000; private static final int[] phi = new int[max+1]; private static final void computePhi() { for ( int i = 1 ; i <= max ; i++ ) { phi[i] = i; } for ( int i = 2 ; i <= max ; i++ ) { if (phi[i] < i) continue; for ( int j = i ; j <= max ; j += i ) { phi[j] -= phi[j] / i; } } } }
Write a version of this C++ function in Java with identical behavior.
template<bool Condition, typename ThenType, typename Elsetype> struct ifthenelse; template<typename ThenType, typename ElseType> struct ifthenelse<true, ThenType, ElseType> { typedef ThenType type; }; template<typename ThenType, typename ElseType> struct ifthenelse<false, ThenType, ElseType> { typedef ElseType type; }; ifthenelse<INT_MAX == 32767, long int, int> ::type myvar;
if (s == 'Hello World') { foo(); } else if (s == 'Bye World') { bar(); } else { deusEx(); }
Maintain the same structure and functionality when rewriting this code in Java.
#include <iostream> #include <sstream> #include <iterator> #include <vector> #include <cmath> using namespace std; class fractran { public: void run( std::string p, int s, int l ) { start = s; limit = l; istringstream iss( p ); vector<string> tmp; copy( istream_iterator<string>( iss ), istream_iterator<string>(), back_inserter<vector<string> >( tmp ) ); string item; vector< pair<float, float> > v; pair<float, float> a; for( vector<string>::iterator i = tmp.begin(); i != tmp.end(); i++ ) { string::size_type pos = ( *i ).find( '/', 0 ); if( pos != std::string::npos ) { a = make_pair( atof( ( ( *i ).substr( 0, pos ) ).c_str() ), atof( ( ( *i ).substr( pos + 1 ) ).c_str() ) ); v.push_back( a ); } } exec( &v ); } private: void exec( vector< pair<float, float> >* v ) { int cnt = 0; while( cnt < limit ) { cout << cnt << " : " << start << "\n"; cnt++; vector< pair<float, float> >::iterator it = v->begin(); bool found = false; float r; while( it != v->end() ) { r = start * ( ( *it ).first / ( *it ).second ); if( r == floor( r ) ) { found = true; break; } ++it; } if( found ) start = ( int )r; else break; } } int start, limit; }; int main( int argc, char* argv[] ) { fractran f; f.run( "17/91 78/85 19/51 23/38 29/33 77/29 95/23 77/19 1/17 11/13 13/11 15/14 15/2 55/1", 2, 15 ); cin.get(); return 0; }
import java.util.Vector; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Fractran{ public static void main(String []args){ new Fractran("17/91 78/85 19/51 23/38 29/33 77/29 95/23 77/19 1/17 11/13 13/11 15/14 15/2 55/1", 2); } final int limit = 15; Vector<Integer> num = new Vector<>(); Vector<Integer> den = new Vector<>(); public Fractran(String prog, Integer val){ compile(prog); dump(); exec(2); } void compile(String prog){ Pattern regexp = Pattern.compile("\\s*(\\d*)\\s*\\/\\s*(\\d*)\\s*(.*)"); Matcher matcher = regexp.matcher(prog); while(matcher.find()){ num.add(Integer.parseInt(matcher.group(1))); den.add(Integer.parseInt(matcher.group(2))); matcher = regexp.matcher(matcher.group(3)); } } void exec(Integer val){ int n = 0; while(val != null && n<limit){ System.out.println(n+": "+val); val = step(val); n++; } } Integer step(int val){ int i=0; while(i<den.size() && val%den.get(i) != 0) i++; if(i<den.size()) return num.get(i)*val/den.get(i); return null; } void dump(){ for(int i=0; i<den.size(); i++) System.out.print(num.get(i)+"/"+den.get(i)+" "); System.out.println(); } }
Maintain the same structure and functionality when rewriting this code in Java.
#include <iostream> #include <time.h> using namespace std; class stooge { public: void sort( int* arr, int start, int end ) { if( arr[start] > arr[end - 1] ) swap( arr[start], arr[end - 1] ); int n = end - start; if( n > 2 ) { n /= 3; sort( arr, start, end - n ); sort( arr, start + n, end ); sort( arr, start, end - n ); } } }; int main( int argc, char* argv[] ) { srand( static_cast<unsigned int>( time( NULL ) ) ); stooge s; int a[80], m = 80; cout << "before:\n"; for( int x = 0; x < m; x++ ) { a[x] = rand() % 40 - 20; cout << a[x] << " "; } s.sort( a, 0, m ); cout << "\n\nafter:\n"; for( int x = 0; x < m; x++ ) cout << a[x] << " "; cout << "\n\n"; return system( "pause" ); }
import java.util.Arrays; public class Stooge { public static void main(String[] args) { int[] nums = {1, 4, 5, 3, -6, 3, 7, 10, -2, -5}; stoogeSort(nums); System.out.println(Arrays.toString(nums)); } public static void stoogeSort(int[] L) { stoogeSort(L, 0, L.length - 1); } public static void stoogeSort(int[] L, int i, int j) { if (L[j] < L[i]) { int tmp = L[i]; L[i] = L[j]; L[j] = tmp; } if (j - i > 1) { int t = (j - i + 1) / 3; stoogeSort(L, i, j - t); stoogeSort(L, i + t, j); stoogeSort(L, i, j - t); } } }
Change the following C++ code into Java without altering its purpose.
#include "stdafx.h" #include <windows.h> #include <stdlib.h> const int BMP_WID = 410, BMP_HEI = 230, MAX_BALLS = 120; class myBitmap { public: myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {} ~myBitmap() { DeleteObject( pen ); DeleteObject( brush ); DeleteDC( hdc ); DeleteObject( bmp ); } bool create( int w, int h ) { BITMAPINFO bi; ZeroMemory( &bi, sizeof( bi ) ); bi.bmiHeader.biSize = sizeof( bi.bmiHeader ); bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8; bi.bmiHeader.biCompression = BI_RGB; bi.bmiHeader.biPlanes = 1; bi.bmiHeader.biWidth = w; bi.bmiHeader.biHeight = -h; HDC dc = GetDC( GetConsoleWindow() ); bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 ); if( !bmp ) return false; hdc = CreateCompatibleDC( dc ); SelectObject( hdc, bmp ); ReleaseDC( GetConsoleWindow(), dc ); width = w; height = h; return true; } void clear( BYTE clr = 0 ) { memset( pBits, clr, width * height * sizeof( DWORD ) ); } void setBrushColor( DWORD bClr ) { if( brush ) DeleteObject( brush ); brush = CreateSolidBrush( bClr ); SelectObject( hdc, brush ); } void setPenColor( DWORD c ) { clr = c; createPen(); } void setPenWidth( int w ) { wid = w; createPen(); } HDC getDC() const { return hdc; } int getWidth() const { return width; } int getHeight() const { return height; } private: void createPen() { if( pen ) DeleteObject( pen ); pen = CreatePen( PS_SOLID, wid, clr ); SelectObject( hdc, pen ); } HBITMAP bmp; HDC hdc; HPEN pen; HBRUSH brush; void *pBits; int width, height, wid; DWORD clr; }; class point { public: int x; float y; void set( int a, float b ) { x = a; y = b; } }; typedef struct { point position, offset; bool alive, start; }ball; class galton { public : galton() { bmp.create( BMP_WID, BMP_HEI ); initialize(); } void setHWND( HWND hwnd ) { _hwnd = hwnd; } void simulate() { draw(); update(); Sleep( 1 ); } private: void draw() { bmp.clear(); bmp.setPenColor( RGB( 0, 255, 0 ) ); bmp.setBrushColor( RGB( 0, 255, 0 ) ); int xx, yy; for( int y = 3; y < 14; y++ ) { yy = 10 * y; for( int x = 0; x < 41; x++ ) { xx = 10 * x; if( pins[y][x] ) Rectangle( bmp.getDC(), xx - 3, yy - 3, xx + 3, yy + 3 ); } } bmp.setPenColor( RGB( 255, 0, 0 ) ); bmp.setBrushColor( RGB( 255, 0, 0 ) ); ball* b; for( int x = 0; x < MAX_BALLS; x++ ) { b = &balls[x]; if( b->alive ) Rectangle( bmp.getDC(), static_cast<int>( b->position.x - 3 ), static_cast<int>( b->position.y - 3 ), static_cast<int>( b->position.x + 3 ), static_cast<int>( b->position.y + 3 ) ); } for( int x = 0; x < 70; x++ ) { if( cols[x] > 0 ) { xx = 10 * x; Rectangle( bmp.getDC(), xx - 3, 160, xx + 3, 160 + cols[x] ); } } HDC dc = GetDC( _hwnd ); BitBlt( dc, 0, 0, BMP_WID, BMP_HEI, bmp.getDC(), 0, 0, SRCCOPY ); ReleaseDC( _hwnd, dc ); } void update() { ball* b; for( int x = 0; x < MAX_BALLS; x++ ) { b = &balls[x]; if( b->alive ) { b->position.x += b->offset.x; b->position.y += b->offset.y; if( x < MAX_BALLS - 1 && !b->start && b->position.y > 50.0f ) { b->start = true; balls[x + 1].alive = true; } int c = ( int )b->position.x, d = ( int )b->position.y + 6; if( d > 10 || d < 41 ) { if( pins[d / 10][c / 10] ) { if( rand() % 30 < 15 ) b->position.x -= 10; else b->position.x += 10; } } if( b->position.y > 160 ) { b->alive = false; cols[c / 10] += 1; } } } } void initialize() { for( int x = 0; x < MAX_BALLS; x++ ) { balls[x].position.set( 200, -10 ); balls[x].offset.set( 0, 0.5f ); balls[x].alive = balls[x].start = false; } balls[0].alive = true; for( int x = 0; x < 70; x++ ) cols[x] = 0; for( int y = 0; y < 70; y++ ) for( int x = 0; x < 41; x++ ) pins[x][y] = false; int p; for( int y = 0; y < 11; y++ ) { p = ( 41 / 2 ) - y; for( int z = 0; z < y + 1; z++ ) { pins[3 + y][p] = true; p += 2; } } } myBitmap bmp; HWND _hwnd; bool pins[70][40]; ball balls[MAX_BALLS]; int cols[70]; }; class wnd { public: int wnd::Run( HINSTANCE hInst ) { _hInst = hInst; _hwnd = InitAll(); _gtn.setHWND( _hwnd ); ShowWindow( _hwnd, SW_SHOW ); UpdateWindow( _hwnd ); MSG msg; ZeroMemory( &msg, sizeof( msg ) ); while( msg.message != WM_QUIT ) { if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) != 0 ) { TranslateMessage( &msg ); DispatchMessage( &msg ); } else _gtn.simulate(); } return UnregisterClass( "_GALTON_", _hInst ); } private: static int WINAPI wnd::WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ) { switch( msg ) { case WM_DESTROY: PostQuitMessage( 0 ); break; default: return static_cast<int>( DefWindowProc( hWnd, msg, wParam, lParam ) ); } return 0; } HWND InitAll() { WNDCLASSEX wcex; ZeroMemory( &wcex, sizeof( wcex ) ); wcex.cbSize = sizeof( WNDCLASSEX ); wcex.style = CS_HREDRAW | CS_VREDRAW; wcex.lpfnWndProc = ( WNDPROC )WndProc; wcex.hInstance = _hInst; wcex.hCursor = LoadCursor( NULL, IDC_ARROW ); wcex.hbrBackground = ( HBRUSH )( COLOR_WINDOW + 1 ); wcex.lpszClassName = "_GALTON_"; RegisterClassEx( &wcex ); RECT rc; SetRect( &rc, 0, 0, BMP_WID, BMP_HEI ); AdjustWindowRect( &rc, WS_CAPTION, FALSE ); return CreateWindow( "_GALTON_", ".: Galton Box -- PJorente :.", WS_SYSMENU, CW_USEDEFAULT, 0, rc.right - rc.left, rc.bottom - rc.top, NULL, NULL, _hInst, NULL ); } HINSTANCE _hInst; HWND _hwnd; galton _gtn; }; int APIENTRY WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow ) { srand( GetTickCount() ); wnd myWnd; return myWnd.Run( hInstance ); }
import java.util.Random; import java.util.List; import java.util.ArrayList; public class GaltonBox { public static void main( final String[] args ) { new GaltonBox( 8, 200 ).run(); } private final int m_pinRows; private final int m_startRow; private final Position[] m_balls; private final Random m_random = new Random(); public GaltonBox( final int pinRows, final int ballCount ) { m_pinRows = pinRows; m_startRow = pinRows + 1; m_balls = new Position[ ballCount ]; for ( int ball = 0; ball < ballCount; ball++ ) m_balls[ ball ] = new Position( m_startRow, 0, 'o' ); } private static class Position { int m_row; int m_col; char m_char; Position( final int row, final int col, final char ch ) { m_row = row; m_col = col; m_char = ch; } } public void run() { for ( int ballsInPlay = m_balls.length; ballsInPlay > 0; ) { ballsInPlay = dropBalls(); print(); } } private int dropBalls() { int ballsInPlay = 0; int ballToStart = -1; for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == m_startRow ) ballToStart = ball; for ( int ball = 0; ball < m_balls.length; ball++ ) if ( ball == ballToStart ) { m_balls[ ball ].m_row = m_pinRows; ballsInPlay++; } else if ( m_balls[ ball ].m_row > 0 && m_balls[ ball ].m_row != m_startRow ) { m_balls[ ball ].m_row -= 1; m_balls[ ball ].m_col += m_random.nextInt( 2 ); if ( 0 != m_balls[ ball ].m_row ) ballsInPlay++; } return ballsInPlay; } private void print() { for ( int row = m_startRow; row --> 1; ) { for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == row ) printBall( m_balls[ ball ] ); System.out.println(); printPins( row ); } printCollectors(); System.out.println(); } private static void printBall( final Position pos ) { for ( int col = pos.m_row + 1; col --> 0; ) System.out.print( ' ' ); for ( int col = 0; col < pos.m_col; col++ ) System.out.print( " " ); System.out.print( pos.m_char ); } private void printPins( final int row ) { for ( int col = row + 1; col --> 0; ) System.out.print( ' ' ); for ( int col = m_startRow - row; col --> 0; ) System.out.print( ". " ); System.out.println(); } private void printCollectors() { final List<List<Position>> collectors = new ArrayList<List<Position>>(); for ( int col = 0; col < m_startRow; col++ ) { final List<Position> collector = new ArrayList<Position>(); collectors.add( collector ); for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == 0 && m_balls[ ball ].m_col == col ) collector.add( m_balls[ ball ] ); } for ( int row = 0, rows = longest( collectors ); row < rows; row++ ) { for ( int col = 0; col < m_startRow; col++ ) { final List<Position> collector = collectors.get( col ); final int pos = row + collector.size() - rows; System.out.print( '|' ); if ( pos >= 0 ) System.out.print( collector.get( pos ).m_char ); else System.out.print( ' ' ); } System.out.println( '|' ); } } private static final int longest( final List<List<Position>> collectors ) { int result = 0; for ( final List<Position> collector : collectors ) result = Math.max( collector.size(), result ); return result; } }
Rewrite the snippet below in Java so it works the same as the original C++ code.
#include "stdafx.h" #include <windows.h> #include <stdlib.h> const int BMP_WID = 410, BMP_HEI = 230, MAX_BALLS = 120; class myBitmap { public: myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {} ~myBitmap() { DeleteObject( pen ); DeleteObject( brush ); DeleteDC( hdc ); DeleteObject( bmp ); } bool create( int w, int h ) { BITMAPINFO bi; ZeroMemory( &bi, sizeof( bi ) ); bi.bmiHeader.biSize = sizeof( bi.bmiHeader ); bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8; bi.bmiHeader.biCompression = BI_RGB; bi.bmiHeader.biPlanes = 1; bi.bmiHeader.biWidth = w; bi.bmiHeader.biHeight = -h; HDC dc = GetDC( GetConsoleWindow() ); bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 ); if( !bmp ) return false; hdc = CreateCompatibleDC( dc ); SelectObject( hdc, bmp ); ReleaseDC( GetConsoleWindow(), dc ); width = w; height = h; return true; } void clear( BYTE clr = 0 ) { memset( pBits, clr, width * height * sizeof( DWORD ) ); } void setBrushColor( DWORD bClr ) { if( brush ) DeleteObject( brush ); brush = CreateSolidBrush( bClr ); SelectObject( hdc, brush ); } void setPenColor( DWORD c ) { clr = c; createPen(); } void setPenWidth( int w ) { wid = w; createPen(); } HDC getDC() const { return hdc; } int getWidth() const { return width; } int getHeight() const { return height; } private: void createPen() { if( pen ) DeleteObject( pen ); pen = CreatePen( PS_SOLID, wid, clr ); SelectObject( hdc, pen ); } HBITMAP bmp; HDC hdc; HPEN pen; HBRUSH brush; void *pBits; int width, height, wid; DWORD clr; }; class point { public: int x; float y; void set( int a, float b ) { x = a; y = b; } }; typedef struct { point position, offset; bool alive, start; }ball; class galton { public : galton() { bmp.create( BMP_WID, BMP_HEI ); initialize(); } void setHWND( HWND hwnd ) { _hwnd = hwnd; } void simulate() { draw(); update(); Sleep( 1 ); } private: void draw() { bmp.clear(); bmp.setPenColor( RGB( 0, 255, 0 ) ); bmp.setBrushColor( RGB( 0, 255, 0 ) ); int xx, yy; for( int y = 3; y < 14; y++ ) { yy = 10 * y; for( int x = 0; x < 41; x++ ) { xx = 10 * x; if( pins[y][x] ) Rectangle( bmp.getDC(), xx - 3, yy - 3, xx + 3, yy + 3 ); } } bmp.setPenColor( RGB( 255, 0, 0 ) ); bmp.setBrushColor( RGB( 255, 0, 0 ) ); ball* b; for( int x = 0; x < MAX_BALLS; x++ ) { b = &balls[x]; if( b->alive ) Rectangle( bmp.getDC(), static_cast<int>( b->position.x - 3 ), static_cast<int>( b->position.y - 3 ), static_cast<int>( b->position.x + 3 ), static_cast<int>( b->position.y + 3 ) ); } for( int x = 0; x < 70; x++ ) { if( cols[x] > 0 ) { xx = 10 * x; Rectangle( bmp.getDC(), xx - 3, 160, xx + 3, 160 + cols[x] ); } } HDC dc = GetDC( _hwnd ); BitBlt( dc, 0, 0, BMP_WID, BMP_HEI, bmp.getDC(), 0, 0, SRCCOPY ); ReleaseDC( _hwnd, dc ); } void update() { ball* b; for( int x = 0; x < MAX_BALLS; x++ ) { b = &balls[x]; if( b->alive ) { b->position.x += b->offset.x; b->position.y += b->offset.y; if( x < MAX_BALLS - 1 && !b->start && b->position.y > 50.0f ) { b->start = true; balls[x + 1].alive = true; } int c = ( int )b->position.x, d = ( int )b->position.y + 6; if( d > 10 || d < 41 ) { if( pins[d / 10][c / 10] ) { if( rand() % 30 < 15 ) b->position.x -= 10; else b->position.x += 10; } } if( b->position.y > 160 ) { b->alive = false; cols[c / 10] += 1; } } } } void initialize() { for( int x = 0; x < MAX_BALLS; x++ ) { balls[x].position.set( 200, -10 ); balls[x].offset.set( 0, 0.5f ); balls[x].alive = balls[x].start = false; } balls[0].alive = true; for( int x = 0; x < 70; x++ ) cols[x] = 0; for( int y = 0; y < 70; y++ ) for( int x = 0; x < 41; x++ ) pins[x][y] = false; int p; for( int y = 0; y < 11; y++ ) { p = ( 41 / 2 ) - y; for( int z = 0; z < y + 1; z++ ) { pins[3 + y][p] = true; p += 2; } } } myBitmap bmp; HWND _hwnd; bool pins[70][40]; ball balls[MAX_BALLS]; int cols[70]; }; class wnd { public: int wnd::Run( HINSTANCE hInst ) { _hInst = hInst; _hwnd = InitAll(); _gtn.setHWND( _hwnd ); ShowWindow( _hwnd, SW_SHOW ); UpdateWindow( _hwnd ); MSG msg; ZeroMemory( &msg, sizeof( msg ) ); while( msg.message != WM_QUIT ) { if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) != 0 ) { TranslateMessage( &msg ); DispatchMessage( &msg ); } else _gtn.simulate(); } return UnregisterClass( "_GALTON_", _hInst ); } private: static int WINAPI wnd::WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ) { switch( msg ) { case WM_DESTROY: PostQuitMessage( 0 ); break; default: return static_cast<int>( DefWindowProc( hWnd, msg, wParam, lParam ) ); } return 0; } HWND InitAll() { WNDCLASSEX wcex; ZeroMemory( &wcex, sizeof( wcex ) ); wcex.cbSize = sizeof( WNDCLASSEX ); wcex.style = CS_HREDRAW | CS_VREDRAW; wcex.lpfnWndProc = ( WNDPROC )WndProc; wcex.hInstance = _hInst; wcex.hCursor = LoadCursor( NULL, IDC_ARROW ); wcex.hbrBackground = ( HBRUSH )( COLOR_WINDOW + 1 ); wcex.lpszClassName = "_GALTON_"; RegisterClassEx( &wcex ); RECT rc; SetRect( &rc, 0, 0, BMP_WID, BMP_HEI ); AdjustWindowRect( &rc, WS_CAPTION, FALSE ); return CreateWindow( "_GALTON_", ".: Galton Box -- PJorente :.", WS_SYSMENU, CW_USEDEFAULT, 0, rc.right - rc.left, rc.bottom - rc.top, NULL, NULL, _hInst, NULL ); } HINSTANCE _hInst; HWND _hwnd; galton _gtn; }; int APIENTRY WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow ) { srand( GetTickCount() ); wnd myWnd; return myWnd.Run( hInstance ); }
import java.util.Random; import java.util.List; import java.util.ArrayList; public class GaltonBox { public static void main( final String[] args ) { new GaltonBox( 8, 200 ).run(); } private final int m_pinRows; private final int m_startRow; private final Position[] m_balls; private final Random m_random = new Random(); public GaltonBox( final int pinRows, final int ballCount ) { m_pinRows = pinRows; m_startRow = pinRows + 1; m_balls = new Position[ ballCount ]; for ( int ball = 0; ball < ballCount; ball++ ) m_balls[ ball ] = new Position( m_startRow, 0, 'o' ); } private static class Position { int m_row; int m_col; char m_char; Position( final int row, final int col, final char ch ) { m_row = row; m_col = col; m_char = ch; } } public void run() { for ( int ballsInPlay = m_balls.length; ballsInPlay > 0; ) { ballsInPlay = dropBalls(); print(); } } private int dropBalls() { int ballsInPlay = 0; int ballToStart = -1; for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == m_startRow ) ballToStart = ball; for ( int ball = 0; ball < m_balls.length; ball++ ) if ( ball == ballToStart ) { m_balls[ ball ].m_row = m_pinRows; ballsInPlay++; } else if ( m_balls[ ball ].m_row > 0 && m_balls[ ball ].m_row != m_startRow ) { m_balls[ ball ].m_row -= 1; m_balls[ ball ].m_col += m_random.nextInt( 2 ); if ( 0 != m_balls[ ball ].m_row ) ballsInPlay++; } return ballsInPlay; } private void print() { for ( int row = m_startRow; row --> 1; ) { for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == row ) printBall( m_balls[ ball ] ); System.out.println(); printPins( row ); } printCollectors(); System.out.println(); } private static void printBall( final Position pos ) { for ( int col = pos.m_row + 1; col --> 0; ) System.out.print( ' ' ); for ( int col = 0; col < pos.m_col; col++ ) System.out.print( " " ); System.out.print( pos.m_char ); } private void printPins( final int row ) { for ( int col = row + 1; col --> 0; ) System.out.print( ' ' ); for ( int col = m_startRow - row; col --> 0; ) System.out.print( ". " ); System.out.println(); } private void printCollectors() { final List<List<Position>> collectors = new ArrayList<List<Position>>(); for ( int col = 0; col < m_startRow; col++ ) { final List<Position> collector = new ArrayList<Position>(); collectors.add( collector ); for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == 0 && m_balls[ ball ].m_col == col ) collector.add( m_balls[ ball ] ); } for ( int row = 0, rows = longest( collectors ); row < rows; row++ ) { for ( int col = 0; col < m_startRow; col++ ) { final List<Position> collector = collectors.get( col ); final int pos = row + collector.size() - rows; System.out.print( '|' ); if ( pos >= 0 ) System.out.print( collector.get( pos ).m_char ); else System.out.print( ' ' ); } System.out.println( '|' ); } } private static final int longest( final List<List<Position>> collectors ) { int result = 0; for ( final List<Position> collector : collectors ) result = Math.max( collector.size(), result ); return result; } }
Convert this C++ block to Java, preserving its control flow and logic.
#include <iostream> int circlesort(int* arr, int lo, int hi, int swaps) { if(lo == hi) { return swaps; } int high = hi; int low = lo; int mid = (high - low) / 2; while(lo < hi) { if(arr[lo] > arr[hi]) { int temp = arr[lo]; arr[lo] = arr[hi]; arr[hi] = temp; swaps++; } lo++; hi--; } if(lo == hi) { if(arr[lo] > arr[hi+1]) { int temp = arr[lo]; arr[lo] = arr[hi+1]; arr[hi+1] = temp; swaps++; } } swaps = circlesort(arr, low, low+mid, swaps); swaps = circlesort(arr, low+mid+1, high, swaps); return swaps; } void circlesortDriver(int* arr, int n) { do { for(int i = 0; i < n; i++) { std::cout << arr[i] << ' '; } std::cout << std::endl; } while(circlesort(arr, 0, n-1, 0)); } int main() { int arr[] = { 6, 7, 8, 9, 2, 5, 3, 4, 1 }; circlesortDriver(arr, sizeof(arr)/sizeof(int)); return 0; }
import java.util.Arrays; public class CircleSort { public static void main(String[] args) { circleSort(new int[]{2, 14, 4, 6, 8, 1, 3, 5, 7, 11, 0, 13, 12, -1}); } public static void circleSort(int[] arr) { if (arr.length > 0) do { System.out.println(Arrays.toString(arr)); } while (circleSortR(arr, 0, arr.length - 1, 0) != 0); } private static int circleSortR(int[] arr, int lo, int hi, int numSwaps) { if (lo == hi) return numSwaps; int high = hi; int low = lo; int mid = (hi - lo) / 2; while (lo < hi) { if (arr[lo] > arr[hi]) { swap(arr, lo, hi); numSwaps++; } lo++; hi--; } if (lo == hi && arr[lo] > arr[hi + 1]) { swap(arr, lo, hi + 1); numSwaps++; } numSwaps = circleSortR(arr, low, low + mid, numSwaps); numSwaps = circleSortR(arr, low + mid + 1, high, numSwaps); return numSwaps; } private static void swap(int[] arr, int idx1, int idx2) { int tmp = arr[idx1]; arr[idx1] = arr[idx2]; arr[idx2] = tmp; } }
Convert the following code from C++ to Java, ensuring the logic remains intact.
#include <cassert> #include <vector> #include <QImage> template <typename scalar_type> class matrix { public: matrix(size_t rows, size_t columns) : rows_(rows), columns_(columns), elements_(rows * columns) {} matrix(size_t rows, size_t columns, const std::initializer_list<std::initializer_list<scalar_type>>& values) : rows_(rows), columns_(columns), elements_(rows * columns) { assert(values.size() <= rows_); size_t i = 0; for (const auto& row : values) { assert(row.size() <= columns_); std::copy(begin(row), end(row), &elements_[i]); i += columns_; } } size_t rows() const { return rows_; } size_t columns() const { return columns_; } const scalar_type& operator()(size_t row, size_t column) const { assert(row < rows_); assert(column < columns_); return elements_[row * columns_ + column]; } scalar_type& operator()(size_t row, size_t column) { assert(row < rows_); assert(column < columns_); return elements_[row * columns_ + column]; } private: size_t rows_; size_t columns_; std::vector<scalar_type> elements_; }; template <typename scalar_type> matrix<scalar_type> kronecker_product(const matrix<scalar_type>& a, const matrix<scalar_type>& b) { size_t arows = a.rows(); size_t acolumns = a.columns(); size_t brows = b.rows(); size_t bcolumns = b.columns(); matrix<scalar_type> c(arows * brows, acolumns * bcolumns); for (size_t i = 0; i < arows; ++i) for (size_t j = 0; j < acolumns; ++j) for (size_t k = 0; k < brows; ++k) for (size_t l = 0; l < bcolumns; ++l) c(i*brows + k, j*bcolumns + l) = a(i, j) * b(k, l); return c; } bool kronecker_fractal(const char* fileName, const matrix<unsigned char>& m, int order) { matrix<unsigned char> result = m; for (int i = 0; i < order; ++i) result = kronecker_product(result, m); size_t height = result.rows(); size_t width = result.columns(); size_t bytesPerLine = 4 * ((width + 3)/4); std::vector<uchar> imageData(bytesPerLine * height); for (size_t i = 0; i < height; ++i) for (size_t j = 0; j < width; ++j) imageData[i * bytesPerLine + j] = result(i, j); QImage image(&imageData[0], width, height, bytesPerLine, QImage::Format_Indexed8); QVector<QRgb> colours(2); colours[0] = qRgb(0, 0, 0); colours[1] = qRgb(255, 255, 255); image.setColorTable(colours); return image.save(fileName); } int main() { matrix<unsigned char> matrix1(3, 3, {{0,1,0}, {1,1,1}, {0,1,0}}); matrix<unsigned char> matrix2(3, 3, {{1,1,1}, {1,0,1}, {1,1,1}}); matrix<unsigned char> matrix3(2, 2, {{1,1}, {0,1}}); kronecker_fractal("vicsek.png", matrix1, 5); kronecker_fractal("sierpinski_carpet.png", matrix2, 5); kronecker_fractal("sierpinski_triangle.png", matrix3, 8); return 0; }
package kronecker; public class ProductFractals { public static int[][] product(final int[][] a, final int[][] b) { final int[][] c = new int[a.length*b.length][]; for (int ix = 0; ix < c.length; ix++) { final int num_cols = a[0].length*b[0].length; c[ix] = new int[num_cols]; } for (int ia = 0; ia < a.length; ia++) { for (int ja = 0; ja < a[ia].length; ja++) { for (int ib = 0; ib < b.length; ib++) { for (int jb = 0; jb < b[ib].length; jb++) { c[b.length*ia+ib][b[ib].length*ja+jb] = a[ia][ja] * b[ib][jb]; } } } } return c; } public static void show_matrix(final int[][] m, final char nz, final char z) { for (int im = 0; im < m.length; im++) { for (int jm = 0; jm < m[im].length; jm++) { System.out.print(m[im][jm] == 0 ? z : nz); } System.out.println(); } } public static int[][] power(final int[][] m, final int n) { int[][] m_pow = m; for (int ix = 1; ix < n; ix++) { m_pow = product(m, m_pow); } return m_pow; } private static void test(final int[][] m, final int n) { System.out.println("Test matrix"); show_matrix(m, '*', ' '); final int[][] m_pow = power(m, n); System.out.println("Matrix power " + n); show_matrix(m_pow, '*', ' '); } private static void test1() { final int[][] m = {{0, 1, 0}, {1, 1, 1}, {0, 1, 0}}; test(m, 4); } private static void test2() { final int[][] m = {{1, 1, 1}, {1, 0, 1}, {1, 1, 1}}; test(m, 4); } private static void test3() { final int[][] m = {{1, 0, 1}, {1, 0, 1}, {0, 1, 0}}; test(m, 4); } public static void main(final String[] args) { test1(); test2(); test3(); } }
Convert the following code from C++ to Java, ensuring the logic remains intact.
#include "stdafx.h" #include <iostream> #include <fstream> #include <vector> #include <string> #include <boost/tokenizer.hpp> #include <boost/algorithm/string/case_conv.hpp> using namespace std; using namespace boost; typedef boost::tokenizer<boost::char_separator<char> > Tokenizer; static const char_separator<char> sep(" ","#;,"); struct configs{ string fullname; string favoritefruit; bool needspelling; bool seedsremoved; vector<string> otherfamily; } conf; void parseLine(const string &line, configs &conf) { if (line[0] == '#' || line.empty()) return; Tokenizer tokenizer(line, sep); vector<string> tokens; for (Tokenizer::iterator iter = tokenizer.begin(); iter != tokenizer.end(); iter++) tokens.push_back(*iter); if (tokens[0] == ";"){ algorithm::to_lower(tokens[1]); if (tokens[1] == "needspeeling") conf.needspelling = false; if (tokens[1] == "seedsremoved") conf.seedsremoved = false; } algorithm::to_lower(tokens[0]); if (tokens[0] == "needspeeling") conf.needspelling = true; if (tokens[0] == "seedsremoved") conf.seedsremoved = true; if (tokens[0] == "fullname"){ for (unsigned int i=1; i<tokens.size(); i++) conf.fullname += tokens[i] + " "; conf.fullname.erase(conf.fullname.size() -1, 1); } if (tokens[0] == "favouritefruit") for (unsigned int i=1; i<tokens.size(); i++) conf.favoritefruit += tokens[i]; if (tokens[0] == "otherfamily"){ unsigned int i=1; string tmp; while (i<=tokens.size()){ if ( i == tokens.size() || tokens[i] ==","){ tmp.erase(tmp.size()-1, 1); conf.otherfamily.push_back(tmp); tmp = ""; i++; } else{ tmp += tokens[i]; tmp += " "; i++; } } } } int _tmain(int argc, TCHAR* argv[]) { if (argc != 2) { wstring tmp = argv[0]; wcout << L"Usage: " << tmp << L" <configfile.ini>" << endl; return -1; } ifstream file (argv[1]); if (file.is_open()) while(file.good()) { char line[255]; file.getline(line, 255); string linestring(line); parseLine(linestring, conf); } else { cout << "Unable to open the file" << endl; return -2; } cout << "Fullname= " << conf.fullname << endl; cout << "Favorite Fruit= " << conf.favoritefruit << endl; cout << "Need Spelling= " << (conf.needspelling?"True":"False") << endl; cout << "Seed Removed= " << (conf.seedsremoved?"True":"False") << endl; string otherFamily; for (unsigned int i = 0; i < conf.otherfamily.size(); i++) otherFamily += conf.otherfamily[i] + ", "; otherFamily.erase(otherFamily.size()-2, 2); cout << "Other Family= " << otherFamily << endl; return 0; }
import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.util.Arrays; import java.util.HashMap; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; public class ConfigReader { private static final Pattern LINE_PATTERN = Pattern.compile( "([^ =]+)[ =]?(.*)" ); private static final Map<String, Object> DEFAULTS = new HashMap<String, Object>() {{ put( "needspeeling", false ); put( "seedsremoved", false ); }}; public static void main( final String[] args ) { System.out.println( parseFile( args[ 0 ] ) ); } public static Map<String, Object> parseFile( final String fileName ) { final Map<String, Object> result = new HashMap<String, Object>( DEFAULTS ); BufferedReader reader = null; try { reader = new BufferedReader( new FileReader( fileName ) ); for ( String line; null != ( line = reader.readLine() ); ) { parseLine( line, result ); } } catch ( final IOException x ) { throw new RuntimeException( "Oops: " + x, x ); } finally { if ( null != reader ) try { reader.close(); } catch ( final IOException x2 ) { System.err.println( "Could not close " + fileName + " - " + x2 ); } } return result; } private static void parseLine( final String line, final Map<String, Object> map ) { if ( "".equals( line.trim() ) || line.startsWith( "#" ) || line.startsWith( ";" ) ) return; final Matcher matcher = LINE_PATTERN.matcher( line ); if ( ! matcher.matches() ) { System.err.println( "Bad config line: " + line ); return; } final String key = matcher.group( 1 ).trim().toLowerCase(); final String value = matcher.group( 2 ).trim(); if ( "".equals( value ) ) { map.put( key, true ); } else if ( -1 == value.indexOf( ',' ) ) { map.put( key, value ); } else { final String[] values = value.split( "," ); for ( int i = 0; i < values.length; i++ ) { values[ i ] = values[ i ].trim(); } map.put( key, Arrays.asList( values ) ); } } }
Rewrite this program in Java while keeping its functionality equivalent to the C++ version.
#include "stdafx.h" #include <iostream> #include <fstream> #include <vector> #include <string> #include <boost/tokenizer.hpp> #include <boost/algorithm/string/case_conv.hpp> using namespace std; using namespace boost; typedef boost::tokenizer<boost::char_separator<char> > Tokenizer; static const char_separator<char> sep(" ","#;,"); struct configs{ string fullname; string favoritefruit; bool needspelling; bool seedsremoved; vector<string> otherfamily; } conf; void parseLine(const string &line, configs &conf) { if (line[0] == '#' || line.empty()) return; Tokenizer tokenizer(line, sep); vector<string> tokens; for (Tokenizer::iterator iter = tokenizer.begin(); iter != tokenizer.end(); iter++) tokens.push_back(*iter); if (tokens[0] == ";"){ algorithm::to_lower(tokens[1]); if (tokens[1] == "needspeeling") conf.needspelling = false; if (tokens[1] == "seedsremoved") conf.seedsremoved = false; } algorithm::to_lower(tokens[0]); if (tokens[0] == "needspeeling") conf.needspelling = true; if (tokens[0] == "seedsremoved") conf.seedsremoved = true; if (tokens[0] == "fullname"){ for (unsigned int i=1; i<tokens.size(); i++) conf.fullname += tokens[i] + " "; conf.fullname.erase(conf.fullname.size() -1, 1); } if (tokens[0] == "favouritefruit") for (unsigned int i=1; i<tokens.size(); i++) conf.favoritefruit += tokens[i]; if (tokens[0] == "otherfamily"){ unsigned int i=1; string tmp; while (i<=tokens.size()){ if ( i == tokens.size() || tokens[i] ==","){ tmp.erase(tmp.size()-1, 1); conf.otherfamily.push_back(tmp); tmp = ""; i++; } else{ tmp += tokens[i]; tmp += " "; i++; } } } } int _tmain(int argc, TCHAR* argv[]) { if (argc != 2) { wstring tmp = argv[0]; wcout << L"Usage: " << tmp << L" <configfile.ini>" << endl; return -1; } ifstream file (argv[1]); if (file.is_open()) while(file.good()) { char line[255]; file.getline(line, 255); string linestring(line); parseLine(linestring, conf); } else { cout << "Unable to open the file" << endl; return -2; } cout << "Fullname= " << conf.fullname << endl; cout << "Favorite Fruit= " << conf.favoritefruit << endl; cout << "Need Spelling= " << (conf.needspelling?"True":"False") << endl; cout << "Seed Removed= " << (conf.seedsremoved?"True":"False") << endl; string otherFamily; for (unsigned int i = 0; i < conf.otherfamily.size(); i++) otherFamily += conf.otherfamily[i] + ", "; otherFamily.erase(otherFamily.size()-2, 2); cout << "Other Family= " << otherFamily << endl; return 0; }
import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.util.Arrays; import java.util.HashMap; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; public class ConfigReader { private static final Pattern LINE_PATTERN = Pattern.compile( "([^ =]+)[ =]?(.*)" ); private static final Map<String, Object> DEFAULTS = new HashMap<String, Object>() {{ put( "needspeeling", false ); put( "seedsremoved", false ); }}; public static void main( final String[] args ) { System.out.println( parseFile( args[ 0 ] ) ); } public static Map<String, Object> parseFile( final String fileName ) { final Map<String, Object> result = new HashMap<String, Object>( DEFAULTS ); BufferedReader reader = null; try { reader = new BufferedReader( new FileReader( fileName ) ); for ( String line; null != ( line = reader.readLine() ); ) { parseLine( line, result ); } } catch ( final IOException x ) { throw new RuntimeException( "Oops: " + x, x ); } finally { if ( null != reader ) try { reader.close(); } catch ( final IOException x2 ) { System.err.println( "Could not close " + fileName + " - " + x2 ); } } return result; } private static void parseLine( final String line, final Map<String, Object> map ) { if ( "".equals( line.trim() ) || line.startsWith( "#" ) || line.startsWith( ";" ) ) return; final Matcher matcher = LINE_PATTERN.matcher( line ); if ( ! matcher.matches() ) { System.err.println( "Bad config line: " + line ); return; } final String key = matcher.group( 1 ).trim().toLowerCase(); final String value = matcher.group( 2 ).trim(); if ( "".equals( value ) ) { map.put( key, true ); } else if ( -1 == value.indexOf( ',' ) ) { map.put( key, value ); } else { final String[] values = value.split( "," ); for ( int i = 0; i < values.length; i++ ) { values[ i ] = values[ i ].trim(); } map.put( key, Arrays.asList( values ) ); } } }
Produce a functionally identical Java code for the snippet given in C++.
#include <algorithm> #include <string> #include <cctype> struct icompare_char { bool operator()(char c1, char c2) { return std::toupper(c1) < std::toupper(c2); } }; struct compare { bool operator()(std::string const& s1, std::string const& s2) { if (s1.length() > s2.length()) return true; if (s1.length() < s2.length()) return false; return std::lexicographical_compare(s1.begin(), s1.end(), s2.begin(), s2.end(), icompare_char()); } }; int main() { std::string strings[8] = {"Here", "are", "some", "sample", "strings", "to", "be", "sorted"}; std::sort(strings, strings+8, compare()); return 0; }
import java.util.Comparator; import java.util.Arrays; public class Test { public static void main(String[] args) { String[] strings = {"Here", "are", "some", "sample", "strings", "to", "be", "sorted"}; Arrays.sort(strings, new Comparator<String>() { public int compare(String s1, String s2) { int c = s2.length() - s1.length(); if (c == 0) c = s1.compareToIgnoreCase(s2); return c; } }); for (String s: strings) System.out.print(s + " "); } }
Ensure the translated Java code behaves exactly like the original C++ snippet.
#include <cstdint> #include <algorithm> #include <iostream> #include <sstream> #include <gmpxx.h> typedef mpz_class integer; bool is_prime(const integer& n, int reps = 50) { return mpz_probab_prime_p(n.get_mpz_t(), reps); } std::string to_string(const integer& n) { std::ostringstream out; out << n; return out.str(); } bool is_circular_prime(const integer& p) { if (!is_prime(p)) return false; std::string str(to_string(p)); for (size_t i = 0, n = str.size(); i + 1 < n; ++i) { std::rotate(str.begin(), str.begin() + 1, str.end()); integer p2(str, 10); if (p2 < p || !is_prime(p2)) return false; } return true; } integer next_repunit(const integer& n) { integer p = 1; while (p < n) p = 10 * p + 1; return p; } integer repunit(int digits) { std::string str(digits, '1'); integer p(str); return p; } void test_repunit(int digits) { if (is_prime(repunit(digits), 10)) std::cout << "R(" << digits << ") is probably prime\n"; else std::cout << "R(" << digits << ") is not prime\n"; } int main() { integer p = 2; std::cout << "First 19 circular primes:\n"; for (int count = 0; count < 19; ++p) { if (is_circular_prime(p)) { if (count > 0) std::cout << ", "; std::cout << p; ++count; } } std::cout << '\n'; std::cout << "Next 4 circular primes:\n"; p = next_repunit(p); std::string str(to_string(p)); int digits = str.size(); for (int count = 0; count < 4; ) { if (is_prime(p, 15)) { if (count > 0) std::cout << ", "; std::cout << "R(" << digits << ")"; ++count; } p = repunit(++digits); } std::cout << '\n'; test_repunit(5003); test_repunit(9887); test_repunit(15073); test_repunit(25031); test_repunit(35317); test_repunit(49081); return 0; }
import java.math.BigInteger; import java.util.Arrays; public class CircularPrimes { public static void main(String[] args) { System.out.println("First 19 circular primes:"); int p = 2; for (int count = 0; count < 19; ++p) { if (isCircularPrime(p)) { if (count > 0) System.out.print(", "); System.out.print(p); ++count; } } System.out.println(); System.out.println("Next 4 circular primes:"); int repunit = 1, digits = 1; for (; repunit < p; ++digits) repunit = 10 * repunit + 1; BigInteger bignum = BigInteger.valueOf(repunit); for (int count = 0; count < 4; ) { if (bignum.isProbablePrime(15)) { if (count > 0) System.out.print(", "); System.out.printf("R(%d)", digits); ++count; } ++digits; bignum = bignum.multiply(BigInteger.TEN); bignum = bignum.add(BigInteger.ONE); } System.out.println(); testRepunit(5003); testRepunit(9887); testRepunit(15073); testRepunit(25031); } private static boolean isPrime(int n) { if (n < 2) return false; if (n % 2 == 0) return n == 2; if (n % 3 == 0) return n == 3; for (int p = 5; p * p <= n; p += 4) { if (n % p == 0) return false; p += 2; if (n % p == 0) return false; } return true; } private static int cycle(int n) { int m = n, p = 1; while (m >= 10) { p *= 10; m /= 10; } return m + 10 * (n % p); } private static boolean isCircularPrime(int p) { if (!isPrime(p)) return false; int p2 = cycle(p); while (p2 != p) { if (p2 < p || !isPrime(p2)) return false; p2 = cycle(p2); } return true; } private static void testRepunit(int digits) { BigInteger repunit = repunit(digits); if (repunit.isProbablePrime(15)) System.out.printf("R(%d) is probably prime.\n", digits); else System.out.printf("R(%d) is not prime.\n", digits); } private static BigInteger repunit(int digits) { char[] ch = new char[digits]; Arrays.fill(ch, '1'); return new BigInteger(new String(ch)); } }
Generate an equivalent Java version of this C++ code.
#include "animationwidget.h" #include <QLabel> #include <QTimer> #include <QVBoxLayout> #include <algorithm> AnimationWidget::AnimationWidget(QWidget *parent) : QWidget(parent) { setWindowTitle(tr("Animation")); QFont font("Courier", 24); QLabel* label = new QLabel("Hello World! "); label->setFont(font); QVBoxLayout* layout = new QVBoxLayout(this); layout->addWidget(label); QTimer* timer = new QTimer(this); connect(timer, &QTimer::timeout, this, [label,this]() { QString text = label->text(); std::rotate(text.begin(), text.begin() + (right_ ? text.length() - 1 : 1), text.end()); label->setText(text); }); timer->start(200); } void AnimationWidget::mousePressEvent(QMouseEvent*) { right_ = !right_; }
import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.util.Timer; import java.util.TimerTask; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.WindowConstants; public class Rotate { private static class State { private final String text = "Hello World! "; private int startIndex = 0; private boolean rotateRight = true; } public static void main(String[] args) { State state = new State(); JLabel label = new JLabel(state.text); label.addMouseListener(new MouseAdapter() { @Override public void mouseClicked(MouseEvent event) { state.rotateRight = !state.rotateRight; } }); TimerTask task = new TimerTask() { public void run() { int delta = state.rotateRight ? 1 : -1; state.startIndex = (state.startIndex + state.text.length() + delta) % state.text.length(); label.setText(rotate(state.text, state.startIndex)); } }; Timer timer = new Timer(false); timer.schedule(task, 0, 500); JFrame rot = new JFrame(); rot.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE); rot.add(label); rot.pack(); rot.setLocationRelativeTo(null); rot.addWindowListener(new WindowAdapter() { @Override public void windowClosed(WindowEvent e) { timer.cancel(); } }); rot.setVisible(true); } private static String rotate(String text, int startIdx) { char[] rotated = new char[text.length()]; for (int i = 0; i < text.length(); i++) { rotated[i] = text.charAt((i + startIdx) % text.length()); } return String.valueOf(rotated); } }
Convert the following code from C++ to Java, ensuring the logic remains intact.
#include <algorithm> #include <iostream> #include <iterator> class radix_test { const int bit; public: radix_test(int offset) : bit(offset) {} bool operator()(int value) const { if (bit == 31) return value < 0; else return !(value & (1 << bit)); } }; void lsd_radix_sort(int *first, int *last) { for (int lsb = 0; lsb < 32; ++lsb) { std::stable_partition(first, last, radix_test(lsb)); } } void msd_radix_sort(int *first, int *last, int msb = 31) { if (first != last && msb >= 0) { int *mid = std::partition(first, last, radix_test(msb)); msb--; msd_radix_sort(first, mid, msb); msd_radix_sort(mid, last, msb); } } int main() { int data[] = { 170, 45, 75, -90, -802, 24, 2, 66 }; lsd_radix_sort(data, data + 8); std::copy(data, data + 8, std::ostream_iterator<int>(std::cout, " ")); return 0; }
public static int[] sort(int[] old) { for (int shift = Integer.SIZE - 1; shift > -1; shift--) { int[] tmp = new int[old.length]; int j = 0; for (int i = 0; i < old.length; i++) { boolean move = old[i] << shift >= 0; if (shift == 0 ? !move : move) { tmp[j] = old[i]; j++; } else { old[i - j] = old[i]; } } for (int i = j; i < tmp.length; i++) { tmp[i] = old[i - j]; } old = tmp; } return old; }
Keep all operations the same but rewrite the snippet in Java.
#include <vector> #include <cmath> #include <iostream> #include <algorithm> #include <iterator> void list_comprehension( std::vector<int> & , int ) ; int main( ) { std::vector<int> triangles ; list_comprehension( triangles , 20 ) ; std::copy( triangles.begin( ) , triangles.end( ) , std::ostream_iterator<int>( std::cout , " " ) ) ; std::cout << std::endl ; return 0 ; } void list_comprehension( std::vector<int> & numbers , int upper_border ) { for ( int a = 1 ; a < upper_border ; a++ ) { for ( int b = a + 1 ; b < upper_border ; b++ ) { double c = pow( a * a + b * b , 0.5 ) ; if ( ( c * c ) < pow( upper_border , 2 ) + 1 ) { if ( c == floor( c ) ) { numbers.push_back( a ) ; numbers.push_back( b ) ; numbers.push_back( static_cast<int>( c ) ) ; } } } } }
import java.util.Arrays; import java.util.List; import static java.util.function.Function.identity; import static java.util.stream.Collectors.toList; import static java.util.stream.IntStream.range; public interface PythagComp{ static void main(String... args){ System.out.println(run(20)); } static List<List<Integer>> run(int n){ return range(1, n).mapToObj( x -> range(x, n).mapToObj( y -> range(y, n).mapToObj( z -> new Integer[]{x, y, z} ) ) ) .flatMap(identity()) .flatMap(identity()) .filter(a -> a[0]*a[0] + a[1]*a[1] == a[2]*a[2]) .map(Arrays::asList) .collect(toList()) ; } }
Maintain the same structure and functionality when rewriting this code in Java.
#include <algorithm> #include <iterator> #include <iostream> template<typename ForwardIterator> void selection_sort(ForwardIterator begin, ForwardIterator end) { for(auto i = begin; i != end; ++i) { std::iter_swap(i, std::min_element(i, end)); } } int main() { int a[] = {100, 2, 56, 200, -52, 3, 99, 33, 177, -199}; selection_sort(std::begin(a), std::end(a)); copy(std::begin(a), std::end(a), std::ostream_iterator<int>(std::cout, " ")); std::cout << "\n"; }
public static void sort(int[] nums){ for(int currentPlace = 0;currentPlace<nums.length-1;currentPlace++){ int smallest = Integer.MAX_VALUE; int smallestAt = currentPlace+1; for(int check = currentPlace; check<nums.length;check++){ if(nums[check]<smallest){ smallestAt = check; smallest = nums[check]; } } int temp = nums[currentPlace]; nums[currentPlace] = nums[smallestAt]; nums[smallestAt] = temp; } }
Produce a functionally identical Java code for the snippet given in C++.
#include <algorithm> #include <cassert> #include <iomanip> #include <iostream> int jacobi(int n, int k) { assert(k > 0 && k % 2 == 1); n %= k; int t = 1; while (n != 0) { while (n % 2 == 0) { n /= 2; int r = k % 8; if (r == 3 || r == 5) t = -t; } std::swap(n, k); if (n % 4 == 3 && k % 4 == 3) t = -t; n %= k; } return k == 1 ? t : 0; } void print_table(std::ostream& out, int kmax, int nmax) { out << "n\\k|"; for (int k = 0; k <= kmax; ++k) out << ' ' << std::setw(2) << k; out << "\n----"; for (int k = 0; k <= kmax; ++k) out << "---"; out << '\n'; for (int n = 1; n <= nmax; n += 2) { out << std::setw(2) << n << " |"; for (int k = 0; k <= kmax; ++k) out << ' ' << std::setw(2) << jacobi(k, n); out << '\n'; } } int main() { print_table(std::cout, 20, 21); return 0; }
public class JacobiSymbol { public static void main(String[] args) { int max = 30; System.out.printf("n\\k "); for ( int k = 1 ; k <= max ; k++ ) { System.out.printf("%2d ", k); } System.out.printf("%n"); for ( int n = 1 ; n <= max ; n += 2 ) { System.out.printf("%2d ", n); for ( int k = 1 ; k <= max ; k++ ) { System.out.printf("%2d ", jacobiSymbol(k, n)); } System.out.printf("%n"); } } private static int jacobiSymbol(int k, int n) { if ( k < 0 || n % 2 == 0 ) { throw new IllegalArgumentException("Invalid value. k = " + k + ", n = " + n); } k %= n; int jacobi = 1; while ( k > 0 ) { while ( k % 2 == 0 ) { k /= 2; int r = n % 8; if ( r == 3 || r == 5 ) { jacobi = -jacobi; } } int temp = n; n = k; k = temp; if ( k % 4 == 3 && n % 4 == 3 ) { jacobi = -jacobi; } k %= n; } if ( n == 1 ) { return jacobi; } return 0; } }
Transform the following C++ implementation into Java, maintaining the same output and logic.
#include <algorithm> #include <cassert> #include <iomanip> #include <iostream> int jacobi(int n, int k) { assert(k > 0 && k % 2 == 1); n %= k; int t = 1; while (n != 0) { while (n % 2 == 0) { n /= 2; int r = k % 8; if (r == 3 || r == 5) t = -t; } std::swap(n, k); if (n % 4 == 3 && k % 4 == 3) t = -t; n %= k; } return k == 1 ? t : 0; } void print_table(std::ostream& out, int kmax, int nmax) { out << "n\\k|"; for (int k = 0; k <= kmax; ++k) out << ' ' << std::setw(2) << k; out << "\n----"; for (int k = 0; k <= kmax; ++k) out << "---"; out << '\n'; for (int n = 1; n <= nmax; n += 2) { out << std::setw(2) << n << " |"; for (int k = 0; k <= kmax; ++k) out << ' ' << std::setw(2) << jacobi(k, n); out << '\n'; } } int main() { print_table(std::cout, 20, 21); return 0; }
public class JacobiSymbol { public static void main(String[] args) { int max = 30; System.out.printf("n\\k "); for ( int k = 1 ; k <= max ; k++ ) { System.out.printf("%2d ", k); } System.out.printf("%n"); for ( int n = 1 ; n <= max ; n += 2 ) { System.out.printf("%2d ", n); for ( int k = 1 ; k <= max ; k++ ) { System.out.printf("%2d ", jacobiSymbol(k, n)); } System.out.printf("%n"); } } private static int jacobiSymbol(int k, int n) { if ( k < 0 || n % 2 == 0 ) { throw new IllegalArgumentException("Invalid value. k = " + k + ", n = " + n); } k %= n; int jacobi = 1; while ( k > 0 ) { while ( k % 2 == 0 ) { k /= 2; int r = n % 8; if ( r == 3 || r == 5 ) { jacobi = -jacobi; } } int temp = n; n = k; k = temp; if ( k % 4 == 3 && n % 4 == 3 ) { jacobi = -jacobi; } k %= n; } if ( n == 1 ) { return jacobi; } return 0; } }
Keep all operations the same but rewrite the snippet in Java.
#include <algorithm> #include <array> #include <cmath> #include <iostream> #include <random> #include <vector> template<typename coordinate_type, size_t dimensions> class point { public: point(std::array<coordinate_type, dimensions> c) : coords_(c) {} point(std::initializer_list<coordinate_type> list) { size_t n = std::min(dimensions, list.size()); std::copy_n(list.begin(), n, coords_.begin()); } coordinate_type get(size_t index) const { return coords_[index]; } double distance(const point& pt) const { double dist = 0; for (size_t i = 0; i < dimensions; ++i) { double d = get(i) - pt.get(i); dist += d * d; } return dist; } private: std::array<coordinate_type, dimensions> coords_; }; template<typename coordinate_type, size_t dimensions> std::ostream& operator<<(std::ostream& out, const point<coordinate_type, dimensions>& pt) { out << '('; for (size_t i = 0; i < dimensions; ++i) { if (i > 0) out << ", "; out << pt.get(i); } out << ')'; return out; } template<typename coordinate_type, size_t dimensions> class kdtree { public: typedef point<coordinate_type, dimensions> point_type; private: struct node { node(const point_type& pt) : point_(pt), left_(nullptr), right_(nullptr) {} coordinate_type get(size_t index) const { return point_.get(index); } double distance(const point_type& pt) const { return point_.distance(pt); } point_type point_; node* left_; node* right_; }; node* root_ = nullptr; node* best_ = nullptr; double best_dist_ = 0; size_t visited_ = 0; std::vector<node> nodes_; struct node_cmp { node_cmp(size_t index) : index_(index) {} bool operator()(const node& n1, const node& n2) const { return n1.point_.get(index_) < n2.point_.get(index_); } size_t index_; }; node* make_tree(size_t begin, size_t end, size_t index) { if (end <= begin) return nullptr; size_t n = begin + (end - begin)/2; auto i = nodes_.begin(); std::nth_element(i + begin, i + n, i + end, node_cmp(index)); index = (index + 1) % dimensions; nodes_[n].left_ = make_tree(begin, n, index); nodes_[n].right_ = make_tree(n + 1, end, index); return &nodes_[n]; } void nearest(node* root, const point_type& point, size_t index) { if (root == nullptr) return; ++visited_; double d = root->distance(point); if (best_ == nullptr || d < best_dist_) { best_dist_ = d; best_ = root; } if (best_dist_ == 0) return; double dx = root->get(index) - point.get(index); index = (index + 1) % dimensions; nearest(dx > 0 ? root->left_ : root->right_, point, index); if (dx * dx >= best_dist_) return; nearest(dx > 0 ? root->right_ : root->left_, point, index); } public: kdtree(const kdtree&) = delete; kdtree& operator=(const kdtree&) = delete; template<typename iterator> kdtree(iterator begin, iterator end) : nodes_(begin, end) { root_ = make_tree(0, nodes_.size(), 0); } template<typename func> kdtree(func&& f, size_t n) { nodes_.reserve(n); for (size_t i = 0; i < n; ++i) nodes_.push_back(f()); root_ = make_tree(0, nodes_.size(), 0); } bool empty() const { return nodes_.empty(); } size_t visited() const { return visited_; } double distance() const { return std::sqrt(best_dist_); } const point_type& nearest(const point_type& pt) { if (root_ == nullptr) throw std::logic_error("tree is empty"); best_ = nullptr; visited_ = 0; best_dist_ = 0; nearest(root_, pt, 0); return best_->point_; } }; void test_wikipedia() { typedef point<int, 2> point2d; typedef kdtree<int, 2> tree2d; point2d points[] = { { 2, 3 }, { 5, 4 }, { 9, 6 }, { 4, 7 }, { 8, 1 }, { 7, 2 } }; tree2d tree(std::begin(points), std::end(points)); point2d n = tree.nearest({ 9, 2 }); std::cout << "Wikipedia example data:\n"; std::cout << "nearest point: " << n << '\n'; std::cout << "distance: " << tree.distance() << '\n'; std::cout << "nodes visited: " << tree.visited() << '\n'; } typedef point<double, 3> point3d; typedef kdtree<double, 3> tree3d; struct random_point_generator { random_point_generator(double min, double max) : engine_(std::random_device()()), distribution_(min, max) {} point3d operator()() { double x = distribution_(engine_); double y = distribution_(engine_); double z = distribution_(engine_); return point3d({x, y, z}); } std::mt19937 engine_; std::uniform_real_distribution<double> distribution_; }; void test_random(size_t count) { random_point_generator rpg(0, 1); tree3d tree(rpg, count); point3d pt(rpg()); point3d n = tree.nearest(pt); std::cout << "Random data (" << count << " points):\n"; std::cout << "point: " << pt << '\n'; std::cout << "nearest point: " << n << '\n'; std::cout << "distance: " << tree.distance() << '\n'; std::cout << "nodes visited: " << tree.visited() << '\n'; } int main() { try { test_wikipedia(); std::cout << '\n'; test_random(1000); std::cout << '\n'; test_random(1000000); } catch (const std::exception& e) { std::cerr << e.what() << '\n'; } return 0; }
import java.util.*; public class KdTree { private int dimensions_; private Node root_ = null; private Node best_ = null; private double bestDistance_ = 0; private int visited_ = 0; public KdTree(int dimensions, List<Node> nodes) { dimensions_ = dimensions; root_ = makeTree(nodes, 0, nodes.size(), 0); } public Node findNearest(Node target) { if (root_ == null) throw new IllegalStateException("Tree is empty!"); best_ = null; visited_ = 0; bestDistance_ = 0; nearest(root_, target, 0); return best_; } public int visited() { return visited_; } public double distance() { return Math.sqrt(bestDistance_); } private void nearest(Node root, Node target, int index) { if (root == null) return; ++visited_; double d = root.distance(target); if (best_ == null || d < bestDistance_) { bestDistance_ = d; best_ = root; } if (bestDistance_ == 0) return; double dx = root.get(index) - target.get(index); index = (index + 1) % dimensions_; nearest(dx > 0 ? root.left_ : root.right_, target, index); if (dx * dx >= bestDistance_) return; nearest(dx > 0 ? root.right_ : root.left_, target, index); } private Node makeTree(List<Node> nodes, int begin, int end, int index) { if (end <= begin) return null; int n = begin + (end - begin)/2; Node node = QuickSelect.select(nodes, begin, end - 1, n, new NodeComparator(index)); index = (index + 1) % dimensions_; node.left_ = makeTree(nodes, begin, n, index); node.right_ = makeTree(nodes, n + 1, end, index); return node; } private static class NodeComparator implements Comparator<Node> { private int index_; private NodeComparator(int index) { index_ = index; } public int compare(Node n1, Node n2) { return Double.compare(n1.get(index_), n2.get(index_)); } } public static class Node { private double[] coords_; private Node left_ = null; private Node right_ = null; public Node(double[] coords) { coords_ = coords; } public Node(double x, double y) { this(new double[]{x, y}); } public Node(double x, double y, double z) { this(new double[]{x, y, z}); } double get(int index) { return coords_[index]; } double distance(Node node) { double dist = 0; for (int i = 0; i < coords_.length; ++i) { double d = coords_[i] - node.coords_[i]; dist += d * d; } return dist; } public String toString() { StringBuilder s = new StringBuilder("("); for (int i = 0; i < coords_.length; ++i) { if (i > 0) s.append(", "); s.append(coords_[i]); } s.append(')'); return s.toString(); } } }
Produce a functionally identical Java code for the snippet given in C++.
#include <algorithm> #include <array> #include <cmath> #include <iostream> #include <random> #include <vector> template<typename coordinate_type, size_t dimensions> class point { public: point(std::array<coordinate_type, dimensions> c) : coords_(c) {} point(std::initializer_list<coordinate_type> list) { size_t n = std::min(dimensions, list.size()); std::copy_n(list.begin(), n, coords_.begin()); } coordinate_type get(size_t index) const { return coords_[index]; } double distance(const point& pt) const { double dist = 0; for (size_t i = 0; i < dimensions; ++i) { double d = get(i) - pt.get(i); dist += d * d; } return dist; } private: std::array<coordinate_type, dimensions> coords_; }; template<typename coordinate_type, size_t dimensions> std::ostream& operator<<(std::ostream& out, const point<coordinate_type, dimensions>& pt) { out << '('; for (size_t i = 0; i < dimensions; ++i) { if (i > 0) out << ", "; out << pt.get(i); } out << ')'; return out; } template<typename coordinate_type, size_t dimensions> class kdtree { public: typedef point<coordinate_type, dimensions> point_type; private: struct node { node(const point_type& pt) : point_(pt), left_(nullptr), right_(nullptr) {} coordinate_type get(size_t index) const { return point_.get(index); } double distance(const point_type& pt) const { return point_.distance(pt); } point_type point_; node* left_; node* right_; }; node* root_ = nullptr; node* best_ = nullptr; double best_dist_ = 0; size_t visited_ = 0; std::vector<node> nodes_; struct node_cmp { node_cmp(size_t index) : index_(index) {} bool operator()(const node& n1, const node& n2) const { return n1.point_.get(index_) < n2.point_.get(index_); } size_t index_; }; node* make_tree(size_t begin, size_t end, size_t index) { if (end <= begin) return nullptr; size_t n = begin + (end - begin)/2; auto i = nodes_.begin(); std::nth_element(i + begin, i + n, i + end, node_cmp(index)); index = (index + 1) % dimensions; nodes_[n].left_ = make_tree(begin, n, index); nodes_[n].right_ = make_tree(n + 1, end, index); return &nodes_[n]; } void nearest(node* root, const point_type& point, size_t index) { if (root == nullptr) return; ++visited_; double d = root->distance(point); if (best_ == nullptr || d < best_dist_) { best_dist_ = d; best_ = root; } if (best_dist_ == 0) return; double dx = root->get(index) - point.get(index); index = (index + 1) % dimensions; nearest(dx > 0 ? root->left_ : root->right_, point, index); if (dx * dx >= best_dist_) return; nearest(dx > 0 ? root->right_ : root->left_, point, index); } public: kdtree(const kdtree&) = delete; kdtree& operator=(const kdtree&) = delete; template<typename iterator> kdtree(iterator begin, iterator end) : nodes_(begin, end) { root_ = make_tree(0, nodes_.size(), 0); } template<typename func> kdtree(func&& f, size_t n) { nodes_.reserve(n); for (size_t i = 0; i < n; ++i) nodes_.push_back(f()); root_ = make_tree(0, nodes_.size(), 0); } bool empty() const { return nodes_.empty(); } size_t visited() const { return visited_; } double distance() const { return std::sqrt(best_dist_); } const point_type& nearest(const point_type& pt) { if (root_ == nullptr) throw std::logic_error("tree is empty"); best_ = nullptr; visited_ = 0; best_dist_ = 0; nearest(root_, pt, 0); return best_->point_; } }; void test_wikipedia() { typedef point<int, 2> point2d; typedef kdtree<int, 2> tree2d; point2d points[] = { { 2, 3 }, { 5, 4 }, { 9, 6 }, { 4, 7 }, { 8, 1 }, { 7, 2 } }; tree2d tree(std::begin(points), std::end(points)); point2d n = tree.nearest({ 9, 2 }); std::cout << "Wikipedia example data:\n"; std::cout << "nearest point: " << n << '\n'; std::cout << "distance: " << tree.distance() << '\n'; std::cout << "nodes visited: " << tree.visited() << '\n'; } typedef point<double, 3> point3d; typedef kdtree<double, 3> tree3d; struct random_point_generator { random_point_generator(double min, double max) : engine_(std::random_device()()), distribution_(min, max) {} point3d operator()() { double x = distribution_(engine_); double y = distribution_(engine_); double z = distribution_(engine_); return point3d({x, y, z}); } std::mt19937 engine_; std::uniform_real_distribution<double> distribution_; }; void test_random(size_t count) { random_point_generator rpg(0, 1); tree3d tree(rpg, count); point3d pt(rpg()); point3d n = tree.nearest(pt); std::cout << "Random data (" << count << " points):\n"; std::cout << "point: " << pt << '\n'; std::cout << "nearest point: " << n << '\n'; std::cout << "distance: " << tree.distance() << '\n'; std::cout << "nodes visited: " << tree.visited() << '\n'; } int main() { try { test_wikipedia(); std::cout << '\n'; test_random(1000); std::cout << '\n'; test_random(1000000); } catch (const std::exception& e) { std::cerr << e.what() << '\n'; } return 0; }
import java.util.*; public class KdTree { private int dimensions_; private Node root_ = null; private Node best_ = null; private double bestDistance_ = 0; private int visited_ = 0; public KdTree(int dimensions, List<Node> nodes) { dimensions_ = dimensions; root_ = makeTree(nodes, 0, nodes.size(), 0); } public Node findNearest(Node target) { if (root_ == null) throw new IllegalStateException("Tree is empty!"); best_ = null; visited_ = 0; bestDistance_ = 0; nearest(root_, target, 0); return best_; } public int visited() { return visited_; } public double distance() { return Math.sqrt(bestDistance_); } private void nearest(Node root, Node target, int index) { if (root == null) return; ++visited_; double d = root.distance(target); if (best_ == null || d < bestDistance_) { bestDistance_ = d; best_ = root; } if (bestDistance_ == 0) return; double dx = root.get(index) - target.get(index); index = (index + 1) % dimensions_; nearest(dx > 0 ? root.left_ : root.right_, target, index); if (dx * dx >= bestDistance_) return; nearest(dx > 0 ? root.right_ : root.left_, target, index); } private Node makeTree(List<Node> nodes, int begin, int end, int index) { if (end <= begin) return null; int n = begin + (end - begin)/2; Node node = QuickSelect.select(nodes, begin, end - 1, n, new NodeComparator(index)); index = (index + 1) % dimensions_; node.left_ = makeTree(nodes, begin, n, index); node.right_ = makeTree(nodes, n + 1, end, index); return node; } private static class NodeComparator implements Comparator<Node> { private int index_; private NodeComparator(int index) { index_ = index; } public int compare(Node n1, Node n2) { return Double.compare(n1.get(index_), n2.get(index_)); } } public static class Node { private double[] coords_; private Node left_ = null; private Node right_ = null; public Node(double[] coords) { coords_ = coords; } public Node(double x, double y) { this(new double[]{x, y}); } public Node(double x, double y, double z) { this(new double[]{x, y, z}); } double get(int index) { return coords_[index]; } double distance(Node node) { double dist = 0; for (int i = 0; i < coords_.length; ++i) { double d = coords_[i] - node.coords_[i]; dist += d * d; } return dist; } public String toString() { StringBuilder s = new StringBuilder("("); for (int i = 0; i < coords_.length; ++i) { if (i > 0) s.append(", "); s.append(coords_[i]); } s.append(')'); return s.toString(); } } }
Port the provided C++ code into Java while preserving the original functionality.
#include <iostream> #include <algorithm> void print_square(int i) { std::cout << i*i << " "; } int main() { int ary[]={1,2,3,4,5}; std::for_each(ary,ary+5,print_square); return 0; }
public class ArrayCallback7 { interface IntConsumer { void run(int x); } interface IntToInt { int run(int x); } static void forEach(int[] arr, IntConsumer consumer) { for (int i : arr) { consumer.run(i); } } static void update(int[] arr, IntToInt mapper) { for (int i = 0; i < arr.length; i++) { arr[i] = mapper.run(arr[i]); } } public static void main(String[] args) { int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; forEach(numbers, new IntConsumer() { public void run(int x) { System.out.println(x); } }); update(numbers, new IntToInt() { @Override public int run(int x) { return x * x; } }); forEach(numbers, new IntConsumer() { public void run(int x) { System.out.println(x); } }); } }
Translate this program into Java but keep the logic exactly as in C++.
#include <stdexcept> template <typename Self> class singleton { protected: static Self* sentry; public: static Self& instance() { return *sentry; } singleton() { if(sentry) throw std::logic_error("Error: attempt to instantiate a singleton over a pre-existing one!"); sentry = (Self*)this; } virtual ~singleton() { if(sentry == this) sentry = 0; } }; template <typename Self> Self* singleton<Self>::sentry = 0; #include <iostream> #include <string> using namespace std; class controller : public singleton<controller> { public: controller(string const& name) : name(name) { trace("begin"); } ~controller() { trace("end"); } void work() { trace("doing stuff"); } void trace(string const& message) { cout << name << ": " << message << endl; } string name; }; int main() { controller* first = new controller("first"); controller::instance().work(); delete first; controller second("second"); controller::instance().work(); try { controller goner("goner"); controller::instance().work(); } catch(exception const& error) { cout << error.what() << endl; } controller::instance().work(); controller goner("goner"); controller::instance().work(); }
class Singleton { private static Singleton myInstance; public static Singleton getInstance() { if (myInstance == null) { synchronized(Singleton.class) { if (myInstance == null) { myInstance = new Singleton(); } } } return myInstance; } protected Singleton() { } }
Produce a functionally identical Java code for the snippet given in C++.
#include <iostream> #include <tuple> union conv { int i; float f; }; float nextUp(float d) { if (isnan(d) || d == -INFINITY || d == INFINITY) return d; if (d == 0.0) return FLT_EPSILON; conv c; c.f = d; c.i++; return c.f; } float nextDown(float d) { if (isnan(d) || d == -INFINITY || d == INFINITY) return d; if (d == 0.0) return -FLT_EPSILON; conv c; c.f = d; c.i--; return c.f; } auto safeAdd(float a, float b) { return std::make_tuple(nextDown(a + b), nextUp(a + b)); } int main() { float a = 1.20f; float b = 0.03f; auto result = safeAdd(a, b); printf("(%f + %f) is in the range (%0.16f, %0.16f)\n", a, b, std::get<0>(result), std::get<1>(result)); return 0; }
public class SafeAddition { private static double stepDown(double d) { return Math.nextAfter(d, Double.NEGATIVE_INFINITY); } private static double stepUp(double d) { return Math.nextUp(d); } private static double[] safeAdd(double a, double b) { return new double[]{stepDown(a + b), stepUp(a + b)}; } public static void main(String[] args) { double a = 1.2; double b = 0.03; double[] result = safeAdd(a, b); System.out.printf("(%.2f + %.2f) is in the range %.16f..%.16f", a, b, result[0], result[1]); } }
Convert the following code from C++ to Java, ensuring the logic remains intact.
#include <iostream> #include <string> using namespace std; int main() { string dog = "Benjamin", Dog = "Samba", DOG = "Bernie"; cout << "The three dogs are named " << dog << ", " << Dog << ", and " << DOG << endl; }
String dog = "Benjamin"; String Dog = "Samba"; String DOG = "Bernie"; @Inject Console console; console.print($"There are three dogs named {dog}, {Dog}, and {DOG}");
Ensure the translated Java code behaves exactly like the original C++ snippet.
for(int i = 10; i >= 0; --i) std::cout << i << "\n";
for (int i = 10; i >= 0; i--) { System.out.println(i); }
Preserve the algorithm and functionality while converting the code from C++ to Java.
#include <fstream> using namespace std; int main() { ofstream file("new.txt"); file << "this is a string"; file.close(); return 0; }
import java.io.*; public class Test { public static void main(String[] args) throws IOException { try (BufferedWriter bw = new BufferedWriter(new FileWriter("test.txt"))) { bw.write("abc"); } } }
Rewrite this program in Java while keeping its functionality equivalent to the C++ version.
for(int i = 0; i < 5; ++i) { for(int j = 0; j < i; ++j) std::cout.put('*'); std::cout.put('\n'); }
for (Integer i = 0; i < 5; i++) { String line = ''; for (Integer j = 0; j < i; j++) { line += '*'; } System.debug(line); } List<String> lines = new List<String> { '*', '**', '***', '****', '*****' }; for (String line : lines) { System.debug(line); }
Generate an equivalent Java version of this C++ code.
#include <iostream> #include <cstdint> typedef uint64_t integer; integer reverse(integer n) { integer rev = 0; while (n > 0) { rev = rev * 10 + (n % 10); n /= 10; } return rev; } class palindrome_generator { public: palindrome_generator(int digit) : power_(10), next_(digit * power_ - 1), digit_(digit), even_(false) {} integer next_palindrome() { ++next_; if (next_ == power_ * (digit_ + 1)) { if (even_) power_ *= 10; next_ = digit_ * power_; even_ = !even_; } return next_ * (even_ ? 10 * power_ : power_) + reverse(even_ ? next_ : next_/10); } private: integer power_; integer next_; int digit_; bool even_; }; bool gapful(integer n) { integer m = n; while (m >= 10) m /= 10; return n % (n % 10 + 10 * m) == 0; } template<size_t len> void print(integer (&array)[9][len]) { for (int digit = 1; digit < 10; ++digit) { std::cout << digit << ":"; for (int i = 0; i < len; ++i) std::cout << ' ' << array[digit - 1][i]; std::cout << '\n'; } } int main() { const int n1 = 20, n2 = 15, n3 = 10; const int m1 = 100, m2 = 1000; integer pg1[9][n1]; integer pg2[9][n2]; integer pg3[9][n3]; for (int digit = 1; digit < 10; ++digit) { palindrome_generator pgen(digit); for (int i = 0; i < m2; ) { integer n = pgen.next_palindrome(); if (!gapful(n)) continue; if (i < n1) pg1[digit - 1][i] = n; else if (i < m1 && i >= m1 - n2) pg2[digit - 1][i - (m1 - n2)] = n; else if (i >= m2 - n3) pg3[digit - 1][i - (m2 - n3)] = n; ++i; } } std::cout << "First " << n1 << " palindromic gapful numbers ending in:\n"; print(pg1); std::cout << "\nLast " << n2 << " of first " << m1 << " palindromic gapful numbers ending in:\n"; print(pg2); std::cout << "\nLast " << n3 << " of first " << m2 << " palindromic gapful numbers ending in:\n"; print(pg3); return 0; }
import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class PalindromicGapfulNumbers { public static void main(String[] args) { System.out.println("First 20 palindromic gapful numbers ending in:"); displayMap(getPalindromicGapfulEnding(20, 20)); System.out.printf("%nLast 15 of first 100 palindromic gapful numbers ending in:%n"); displayMap(getPalindromicGapfulEnding(15, 100)); System.out.printf("%nLast 10 of first 1000 palindromic gapful numbers ending in:%n"); displayMap(getPalindromicGapfulEnding(10, 1000)); } private static void displayMap(Map<Integer,List<Long>> map) { for ( int key = 1 ; key <= 9 ; key++ ) { System.out.println(key + " : " + map.get(key)); } } public static Map<Integer,List<Long>> getPalindromicGapfulEnding(int countReturned, int firstHowMany) { Map<Integer,List<Long>> map = new HashMap<>(); Map<Integer,Integer> mapCount = new HashMap<>(); for ( int i = 1 ; i <= 9 ; i++ ) { map.put(i, new ArrayList<>()); mapCount.put(i, 0); } boolean notPopulated = true; for ( long n = 101 ; notPopulated ; n = nextPalindrome(n) ) { if ( isGapful(n) ) { int index = (int) (n % 10); if ( mapCount.get(index) < firstHowMany ) { map.get(index).add(n); mapCount.put(index, mapCount.get(index) + 1); if ( map.get(index).size() > countReturned ) { map.get(index).remove(0); } } boolean finished = true; for ( int i = 1 ; i <= 9 ; i++ ) { if ( mapCount.get(i) < firstHowMany ) { finished = false; break; } } if ( finished ) { notPopulated = false; } } } return map; } public static boolean isGapful(long n) { String s = Long.toString(n); return n % Long.parseLong("" + s.charAt(0) + s.charAt(s.length()-1)) == 0; } public static int length(long n) { int length = 0; while ( n > 0 ) { length += 1; n /= 10; } return length; } public static long nextPalindrome(long n) { int length = length(n); if ( length % 2 == 0 ) { length /= 2; while ( length > 0 ) { n /= 10; length--; } n += 1; if ( powerTen(n) ) { return Long.parseLong(n + reverse(n/10)); } return Long.parseLong(n + reverse(n)); } length = (length - 1) / 2; while ( length > 0 ) { n /= 10; length--; } n += 1; if ( powerTen(n) ) { return Long.parseLong(n + reverse(n/100)); } return Long.parseLong(n + reverse(n/10)); } private static boolean powerTen(long n) { while ( n > 9 && n % 10 == 0 ) { n /= 10; } return n == 1; } private static String reverse(long n) { return (new StringBuilder(n + "")).reverse().toString(); } }
Keep all operations the same but rewrite the snippet in Java.
#include <iostream> #include <cstdint> typedef uint64_t integer; integer reverse(integer n) { integer rev = 0; while (n > 0) { rev = rev * 10 + (n % 10); n /= 10; } return rev; } class palindrome_generator { public: palindrome_generator(int digit) : power_(10), next_(digit * power_ - 1), digit_(digit), even_(false) {} integer next_palindrome() { ++next_; if (next_ == power_ * (digit_ + 1)) { if (even_) power_ *= 10; next_ = digit_ * power_; even_ = !even_; } return next_ * (even_ ? 10 * power_ : power_) + reverse(even_ ? next_ : next_/10); } private: integer power_; integer next_; int digit_; bool even_; }; bool gapful(integer n) { integer m = n; while (m >= 10) m /= 10; return n % (n % 10 + 10 * m) == 0; } template<size_t len> void print(integer (&array)[9][len]) { for (int digit = 1; digit < 10; ++digit) { std::cout << digit << ":"; for (int i = 0; i < len; ++i) std::cout << ' ' << array[digit - 1][i]; std::cout << '\n'; } } int main() { const int n1 = 20, n2 = 15, n3 = 10; const int m1 = 100, m2 = 1000; integer pg1[9][n1]; integer pg2[9][n2]; integer pg3[9][n3]; for (int digit = 1; digit < 10; ++digit) { palindrome_generator pgen(digit); for (int i = 0; i < m2; ) { integer n = pgen.next_palindrome(); if (!gapful(n)) continue; if (i < n1) pg1[digit - 1][i] = n; else if (i < m1 && i >= m1 - n2) pg2[digit - 1][i - (m1 - n2)] = n; else if (i >= m2 - n3) pg3[digit - 1][i - (m2 - n3)] = n; ++i; } } std::cout << "First " << n1 << " palindromic gapful numbers ending in:\n"; print(pg1); std::cout << "\nLast " << n2 << " of first " << m1 << " palindromic gapful numbers ending in:\n"; print(pg2); std::cout << "\nLast " << n3 << " of first " << m2 << " palindromic gapful numbers ending in:\n"; print(pg3); return 0; }
import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class PalindromicGapfulNumbers { public static void main(String[] args) { System.out.println("First 20 palindromic gapful numbers ending in:"); displayMap(getPalindromicGapfulEnding(20, 20)); System.out.printf("%nLast 15 of first 100 palindromic gapful numbers ending in:%n"); displayMap(getPalindromicGapfulEnding(15, 100)); System.out.printf("%nLast 10 of first 1000 palindromic gapful numbers ending in:%n"); displayMap(getPalindromicGapfulEnding(10, 1000)); } private static void displayMap(Map<Integer,List<Long>> map) { for ( int key = 1 ; key <= 9 ; key++ ) { System.out.println(key + " : " + map.get(key)); } } public static Map<Integer,List<Long>> getPalindromicGapfulEnding(int countReturned, int firstHowMany) { Map<Integer,List<Long>> map = new HashMap<>(); Map<Integer,Integer> mapCount = new HashMap<>(); for ( int i = 1 ; i <= 9 ; i++ ) { map.put(i, new ArrayList<>()); mapCount.put(i, 0); } boolean notPopulated = true; for ( long n = 101 ; notPopulated ; n = nextPalindrome(n) ) { if ( isGapful(n) ) { int index = (int) (n % 10); if ( mapCount.get(index) < firstHowMany ) { map.get(index).add(n); mapCount.put(index, mapCount.get(index) + 1); if ( map.get(index).size() > countReturned ) { map.get(index).remove(0); } } boolean finished = true; for ( int i = 1 ; i <= 9 ; i++ ) { if ( mapCount.get(i) < firstHowMany ) { finished = false; break; } } if ( finished ) { notPopulated = false; } } } return map; } public static boolean isGapful(long n) { String s = Long.toString(n); return n % Long.parseLong("" + s.charAt(0) + s.charAt(s.length()-1)) == 0; } public static int length(long n) { int length = 0; while ( n > 0 ) { length += 1; n /= 10; } return length; } public static long nextPalindrome(long n) { int length = length(n); if ( length % 2 == 0 ) { length /= 2; while ( length > 0 ) { n /= 10; length--; } n += 1; if ( powerTen(n) ) { return Long.parseLong(n + reverse(n/10)); } return Long.parseLong(n + reverse(n)); } length = (length - 1) / 2; while ( length > 0 ) { n /= 10; length--; } n += 1; if ( powerTen(n) ) { return Long.parseLong(n + reverse(n/100)); } return Long.parseLong(n + reverse(n/10)); } private static boolean powerTen(long n) { while ( n > 9 && n % 10 == 0 ) { n /= 10; } return n == 1; } private static String reverse(long n) { return (new StringBuilder(n + "")).reverse().toString(); } }
Rewrite the snippet below in Java so it works the same as the original C++ code.
#include <windows.h> #include <string> #include <iostream> const int BMP_SIZE = 612; class myBitmap { public: myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {} ~myBitmap() { DeleteObject( pen ); DeleteObject( brush ); DeleteDC( hdc ); DeleteObject( bmp ); } bool create( int w, int h ) { BITMAPINFO bi; ZeroMemory( &bi, sizeof( bi ) ); bi.bmiHeader.biSize = sizeof( bi.bmiHeader ); bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8; bi.bmiHeader.biCompression = BI_RGB; bi.bmiHeader.biPlanes = 1; bi.bmiHeader.biWidth = w; bi.bmiHeader.biHeight = -h; HDC dc = GetDC( GetConsoleWindow() ); bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 ); if( !bmp ) return false; hdc = CreateCompatibleDC( dc ); SelectObject( hdc, bmp ); ReleaseDC( GetConsoleWindow(), dc ); width = w; height = h; return true; } void clear( BYTE clr = 0 ) { memset( pBits, clr, width * height * sizeof( DWORD ) ); } void setBrushColor( DWORD bClr ) { if( brush ) DeleteObject( brush ); brush = CreateSolidBrush( bClr ); SelectObject( hdc, brush ); } void setPenColor( DWORD c ) { clr = c; createPen(); } void setPenWidth( int w ) { wid = w; createPen(); } void saveBitmap( std::string path ) { BITMAPFILEHEADER fileheader; BITMAPINFO infoheader; BITMAP bitmap; DWORD wb; GetObject( bmp, sizeof( bitmap ), &bitmap ); DWORD* dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight]; ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) ); ZeroMemory( &infoheader, sizeof( BITMAPINFO ) ); ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) ); infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8; infoheader.bmiHeader.biCompression = BI_RGB; infoheader.bmiHeader.biPlanes = 1; infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader ); infoheader.bmiHeader.biHeight = bitmap.bmHeight; infoheader.bmiHeader.biWidth = bitmap.bmWidth; infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ); fileheader.bfType = 0x4D42; fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER ); fileheader.bfSize = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage; GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS ); HANDLE file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL ); WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL ); WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL ); WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL ); CloseHandle( file ); delete [] dwpBits; } HDC getDC() const { return hdc; } int getWidth() const { return width; } int getHeight() const { return height; } private: void createPen() { if( pen ) DeleteObject( pen ); pen = CreatePen( PS_SOLID, wid, clr ); SelectObject( hdc, pen ); } HBITMAP bmp; HDC hdc; HPEN pen; HBRUSH brush; void *pBits; int width, height, wid; DWORD clr; }; class sierpinski { public: void draw( int o ) { colors[0] = 0xff0000; colors[1] = 0x00ff33; colors[2] = 0x0033ff; colors[3] = 0xffff00; colors[4] = 0x00ffff; colors[5] = 0xffffff; bmp.create( BMP_SIZE, BMP_SIZE ); HDC dc = bmp.getDC(); drawTri( dc, 0, 0, ( float )BMP_SIZE, ( float )BMP_SIZE, o / 2 ); bmp.setPenColor( colors[0] ); MoveToEx( dc, BMP_SIZE >> 1, 0, NULL ); LineTo( dc, 0, BMP_SIZE - 1 ); LineTo( dc, BMP_SIZE - 1, BMP_SIZE - 1 ); LineTo( dc, BMP_SIZE >> 1, 0 ); bmp.saveBitmap( "./st.bmp" ); } private: void drawTri( HDC dc, float l, float t, float r, float b, int i ) { float w = r - l, h = b - t, hh = h / 2.f, ww = w / 4.f; if( i ) { drawTri( dc, l + ww, t, l + ww * 3.f, t + hh, i - 1 ); drawTri( dc, l, t + hh, l + w / 2.f, t + h, i - 1 ); drawTri( dc, l + w / 2.f, t + hh, l + w, t + h, i - 1 ); } bmp.setPenColor( colors[i % 6] ); MoveToEx( dc, ( int )( l + ww ), ( int )( t + hh ), NULL ); LineTo ( dc, ( int )( l + ww * 3.f ), ( int )( t + hh ) ); LineTo ( dc, ( int )( l + ( w / 2.f ) ), ( int )( t + h ) ); LineTo ( dc, ( int )( l + ww ), ( int )( t + hh ) ); } myBitmap bmp; DWORD colors[6]; }; int main(int argc, char* argv[]) { sierpinski s; s.draw( 12 ); return 0; }
import javax.swing.*; import java.awt.*; class SierpinskyTriangle { public static void main(String[] args) { int i = 3; if(args.length >= 1) { try { i = Integer.parseInt(args[0]); } catch(NumberFormatException e) { System.out.println("Usage: 'java SierpinskyTriangle [level]'\nNow setting level to "+i); } } final int level = i; JFrame frame = new JFrame("Sierpinsky Triangle - Java"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel panel = new JPanel() { @Override public void paintComponent(Graphics g) { g.setColor(Color.BLACK); drawSierpinskyTriangle(level, 20, 20, 360, (Graphics2D)g); } }; panel.setPreferredSize(new Dimension(400, 400)); frame.add(panel); frame.pack(); frame.setResizable(false); frame.setLocationRelativeTo(null); frame.setVisible(true); } private static void drawSierpinskyTriangle(int level, int x, int y, int size, Graphics2D g) { if(level <= 0) return; g.drawLine(x, y, x+size, y); g.drawLine(x, y, x, y+size); g.drawLine(x+size, y, x, y+size); drawSierpinskyTriangle(level-1, x, y, size/2, g); drawSierpinskyTriangle(level-1, x+size/2, y, size/2, g); drawSierpinskyTriangle(level-1, x, y+size/2, size/2, g); } }
Write the same algorithm in Java as shown in this C++ implementation.
#include <windows.h> #include <string> #include <iostream> const int BMP_SIZE = 612; class myBitmap { public: myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {} ~myBitmap() { DeleteObject( pen ); DeleteObject( brush ); DeleteDC( hdc ); DeleteObject( bmp ); } bool create( int w, int h ) { BITMAPINFO bi; ZeroMemory( &bi, sizeof( bi ) ); bi.bmiHeader.biSize = sizeof( bi.bmiHeader ); bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8; bi.bmiHeader.biCompression = BI_RGB; bi.bmiHeader.biPlanes = 1; bi.bmiHeader.biWidth = w; bi.bmiHeader.biHeight = -h; HDC dc = GetDC( GetConsoleWindow() ); bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 ); if( !bmp ) return false; hdc = CreateCompatibleDC( dc ); SelectObject( hdc, bmp ); ReleaseDC( GetConsoleWindow(), dc ); width = w; height = h; return true; } void clear( BYTE clr = 0 ) { memset( pBits, clr, width * height * sizeof( DWORD ) ); } void setBrushColor( DWORD bClr ) { if( brush ) DeleteObject( brush ); brush = CreateSolidBrush( bClr ); SelectObject( hdc, brush ); } void setPenColor( DWORD c ) { clr = c; createPen(); } void setPenWidth( int w ) { wid = w; createPen(); } void saveBitmap( std::string path ) { BITMAPFILEHEADER fileheader; BITMAPINFO infoheader; BITMAP bitmap; DWORD wb; GetObject( bmp, sizeof( bitmap ), &bitmap ); DWORD* dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight]; ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) ); ZeroMemory( &infoheader, sizeof( BITMAPINFO ) ); ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) ); infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8; infoheader.bmiHeader.biCompression = BI_RGB; infoheader.bmiHeader.biPlanes = 1; infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader ); infoheader.bmiHeader.biHeight = bitmap.bmHeight; infoheader.bmiHeader.biWidth = bitmap.bmWidth; infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ); fileheader.bfType = 0x4D42; fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER ); fileheader.bfSize = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage; GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS ); HANDLE file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL ); WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL ); WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL ); WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL ); CloseHandle( file ); delete [] dwpBits; } HDC getDC() const { return hdc; } int getWidth() const { return width; } int getHeight() const { return height; } private: void createPen() { if( pen ) DeleteObject( pen ); pen = CreatePen( PS_SOLID, wid, clr ); SelectObject( hdc, pen ); } HBITMAP bmp; HDC hdc; HPEN pen; HBRUSH brush; void *pBits; int width, height, wid; DWORD clr; }; class sierpinski { public: void draw( int o ) { colors[0] = 0xff0000; colors[1] = 0x00ff33; colors[2] = 0x0033ff; colors[3] = 0xffff00; colors[4] = 0x00ffff; colors[5] = 0xffffff; bmp.create( BMP_SIZE, BMP_SIZE ); HDC dc = bmp.getDC(); drawTri( dc, 0, 0, ( float )BMP_SIZE, ( float )BMP_SIZE, o / 2 ); bmp.setPenColor( colors[0] ); MoveToEx( dc, BMP_SIZE >> 1, 0, NULL ); LineTo( dc, 0, BMP_SIZE - 1 ); LineTo( dc, BMP_SIZE - 1, BMP_SIZE - 1 ); LineTo( dc, BMP_SIZE >> 1, 0 ); bmp.saveBitmap( "./st.bmp" ); } private: void drawTri( HDC dc, float l, float t, float r, float b, int i ) { float w = r - l, h = b - t, hh = h / 2.f, ww = w / 4.f; if( i ) { drawTri( dc, l + ww, t, l + ww * 3.f, t + hh, i - 1 ); drawTri( dc, l, t + hh, l + w / 2.f, t + h, i - 1 ); drawTri( dc, l + w / 2.f, t + hh, l + w, t + h, i - 1 ); } bmp.setPenColor( colors[i % 6] ); MoveToEx( dc, ( int )( l + ww ), ( int )( t + hh ), NULL ); LineTo ( dc, ( int )( l + ww * 3.f ), ( int )( t + hh ) ); LineTo ( dc, ( int )( l + ( w / 2.f ) ), ( int )( t + h ) ); LineTo ( dc, ( int )( l + ww ), ( int )( t + hh ) ); } myBitmap bmp; DWORD colors[6]; }; int main(int argc, char* argv[]) { sierpinski s; s.draw( 12 ); return 0; }
import javax.swing.*; import java.awt.*; class SierpinskyTriangle { public static void main(String[] args) { int i = 3; if(args.length >= 1) { try { i = Integer.parseInt(args[0]); } catch(NumberFormatException e) { System.out.println("Usage: 'java SierpinskyTriangle [level]'\nNow setting level to "+i); } } final int level = i; JFrame frame = new JFrame("Sierpinsky Triangle - Java"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel panel = new JPanel() { @Override public void paintComponent(Graphics g) { g.setColor(Color.BLACK); drawSierpinskyTriangle(level, 20, 20, 360, (Graphics2D)g); } }; panel.setPreferredSize(new Dimension(400, 400)); frame.add(panel); frame.pack(); frame.setResizable(false); frame.setLocationRelativeTo(null); frame.setVisible(true); } private static void drawSierpinskyTriangle(int level, int x, int y, int size, Graphics2D g) { if(level <= 0) return; g.drawLine(x, y, x+size, y); g.drawLine(x, y, x, y+size); g.drawLine(x+size, y, x, y+size); drawSierpinskyTriangle(level-1, x, y, size/2, g); drawSierpinskyTriangle(level-1, x+size/2, y, size/2, g); drawSierpinskyTriangle(level-1, x, y+size/2, size/2, g); } }
Translate the given C++ code snippet into Java without altering its behavior.
class N{ uint n,i,g,e,l; public: N(uint n): n(n-1),i{},g{},e(1),l(n-1){} bool hasNext(){ g=(1<<n)+e;for(i=l;i<n;++i) g+=1<<i; if (l==2) {l=--n; e=1; return true;} if (e<((1<<(l-1))-1)) {++e; return true;} e=1; --l; return (l>0); } uint next() {return g;} };
public class NonContinuousSubsequences { public static void main(String args[]) { seqR("1234", "", 0, 0); } private static void seqR(String s, String c, int i, int added) { if (i == s.length()) { if (c.trim().length() > added) System.out.println(c); } else { seqR(s, c + s.charAt(i), i + 1, added + 1); seqR(s, c + ' ', i + 1, added); } } }
Translate the given C++ code snippet into Java without altering its behavior.
#include <windows.h> #include <string> using namespace std; class myBitmap { public: myBitmap() : pen( NULL ) {} ~myBitmap() { DeleteObject( pen ); DeleteDC( hdc ); DeleteObject( bmp ); } bool create( int w, int h ) { BITMAPINFO bi; ZeroMemory( &bi, sizeof( bi ) ); bi.bmiHeader.biSize = sizeof( bi.bmiHeader ); bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8; bi.bmiHeader.biCompression = BI_RGB; bi.bmiHeader.biPlanes = 1; bi.bmiHeader.biWidth = w; bi.bmiHeader.biHeight = -h; HDC dc = GetDC( GetConsoleWindow() ); bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 ); if( !bmp ) return false; hdc = CreateCompatibleDC( dc ); SelectObject( hdc, bmp ); ReleaseDC( GetConsoleWindow(), dc ); width = w; height = h; clear(); return true; } void clear() { ZeroMemory( pBits, width * height * sizeof( DWORD ) ); } void setPenColor( DWORD clr ) { if( pen ) DeleteObject( pen ); pen = CreatePen( PS_SOLID, 1, clr ); SelectObject( hdc, pen ); } void saveBitmap( string path ) { BITMAPFILEHEADER fileheader; BITMAPINFO infoheader; BITMAP bitmap; DWORD* dwpBits; DWORD wb; HANDLE file; GetObject( bmp, sizeof( bitmap ), &bitmap ); dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight]; ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) ); ZeroMemory( &infoheader, sizeof( BITMAPINFO ) ); ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) ); infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8; infoheader.bmiHeader.biCompression = BI_RGB; infoheader.bmiHeader.biPlanes = 1; infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader ); infoheader.bmiHeader.biHeight = bitmap.bmHeight; infoheader.bmiHeader.biWidth = bitmap.bmWidth; infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ); fileheader.bfType = 0x4D42; fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER ); fileheader.bfSize = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage; GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS ); file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL ); WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL ); WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL ); WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL ); CloseHandle( file ); delete [] dwpBits; } HDC getDC() { return hdc; } int getWidth() { return width; } int getHeight() { return height; } private: HBITMAP bmp; HDC hdc; HPEN pen; void *pBits; int width, height; }; class fiboFractal { public: fiboFractal( int l ) { bmp.create( 600, 440 ); bmp.setPenColor( 0x00ff00 ); createWord( l ); createFractal(); bmp.saveBitmap( "path_to_save_bitmap" ); } private: void createWord( int l ) { string a = "1", b = "0", c; l -= 2; while( l-- ) { c = b + a; a = b; b = c; } fWord = c; } void createFractal() { int n = 1, px = 10, dir, py = 420, len = 1, x = 0, y = -len, goingTo = 0; HDC dc = bmp.getDC(); MoveToEx( dc, px, py, NULL ); for( string::iterator si = fWord.begin(); si != fWord.end(); si++ ) { px += x; py += y; LineTo( dc, px, py ); if( !( *si - 48 ) ) { if( n & 1 ) dir = 1; else dir = 0; switch( goingTo ) { case 0: y = 0; if( dir ){ x = len; goingTo = 1; } else { x = -len; goingTo = 3; } break; case 1: x = 0; if( dir ) { y = len; goingTo = 2; } else { y = -len; goingTo = 0; } break; case 2: y = 0; if( dir ) { x = -len; goingTo = 3; } else { x = len; goingTo = 1; } break; case 3: x = 0; if( dir ) { y = -len; goingTo = 0; } else { y = len; goingTo = 2; } } } n++; } } string fWord; myBitmap bmp; }; int main( int argc, char* argv[] ) { fiboFractal ff( 23 ); return system( "pause" ); }
import java.awt.*; import javax.swing.*; public class FibonacciWordFractal extends JPanel { String wordFractal; FibonacciWordFractal(int n) { setPreferredSize(new Dimension(450, 620)); setBackground(Color.white); wordFractal = wordFractal(n); } public String wordFractal(int n) { if (n < 2) return n == 1 ? "1" : ""; StringBuilder f1 = new StringBuilder("1"); StringBuilder f2 = new StringBuilder("0"); for (n = n - 2; n > 0; n--) { String tmp = f2.toString(); f2.append(f1); f1.setLength(0); f1.append(tmp); } return f2.toString(); } void drawWordFractal(Graphics2D g, int x, int y, int dx, int dy) { for (int n = 0; n < wordFractal.length(); n++) { g.drawLine(x, y, x + dx, y + dy); x += dx; y += dy; if (wordFractal.charAt(n) == '0') { int tx = dx; dx = (n % 2 == 0) ? -dy : dy; dy = (n % 2 == 0) ? tx : -tx; } } } @Override public void paintComponent(Graphics gg) { super.paintComponent(gg); Graphics2D g = (Graphics2D) gg; g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); drawWordFractal(g, 20, 20, 1, 0); } public static void main(String[] args) { SwingUtilities.invokeLater(() -> { JFrame f = new JFrame(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setTitle("Fibonacci Word Fractal"); f.setResizable(false); f.add(new FibonacciWordFractal(23), BorderLayout.CENTER); f.pack(); f.setLocationRelativeTo(null); f.setVisible(true); }); } }
Ensure the translated Java code behaves exactly like the original C++ snippet.
#include <cstdint> #include <iostream> #include <string> #include <primesieve.hpp> void print_twin_prime_count(long long limit) { std::cout << "Number of twin prime pairs less than " << limit << " is " << (limit > 0 ? primesieve::count_twins(0, limit - 1) : 0) << '\n'; } int main(int argc, char** argv) { std::cout.imbue(std::locale("")); if (argc > 1) { for (int i = 1; i < argc; ++i) { try { print_twin_prime_count(std::stoll(argv[i])); } catch (const std::exception& ex) { std::cerr << "Cannot parse limit from '" << argv[i] << "'\n"; } } } else { uint64_t limit = 10; for (int power = 1; power < 12; ++power, limit *= 10) print_twin_prime_count(limit); } return 0; }
import java.math.BigInteger; import java.util.Scanner; public class twinPrimes { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("Search Size: "); BigInteger max = input.nextBigInteger(); int counter = 0; for(BigInteger x = new BigInteger("3"); x.compareTo(max) <= 0; x = x.add(BigInteger.ONE)){ BigInteger sqrtNum = x.sqrt().add(BigInteger.ONE); if(x.add(BigInteger.TWO).compareTo(max) <= 0) { counter += findPrime(x.add(BigInteger.TWO), x.add(BigInteger.TWO).sqrt().add(BigInteger.ONE)) && findPrime(x, sqrtNum) ? 1 : 0; } } System.out.println(counter + " twin prime pairs."); } public static boolean findPrime(BigInteger x, BigInteger sqrtNum){ for(BigInteger divisor = BigInteger.TWO; divisor.compareTo(sqrtNum) <= 0; divisor = divisor.add(BigInteger.ONE)){ if(x.remainder(divisor).compareTo(BigInteger.ZERO) == 0){ return false; } } return true; } }
Convert this C++ block to Java, preserving its control flow and logic.
#include <complex> #include <cmath> #include <iostream> double const pi = 4 * std::atan(1); int main() { for (int n = 2; n <= 10; ++n) { std::cout << n << ": "; for (int k = 0; k < n; ++k) std::cout << std::polar(1, 2*pi*k/n) << " "; std::cout << std::endl; } }
import java.util.Locale; public class Test { public static void main(String[] a) { for (int n = 2; n < 6; n++) unity(n); } public static void unity(int n) { System.out.printf("%n%d: ", n); for (double angle = 0; angle < 2 * Math.PI; angle += (2 * Math.PI) / n) { double real = Math.cos(angle); if (Math.abs(real) < 1.0E-3) real = 0.0; double imag = Math.sin(angle); if (Math.abs(imag) < 1.0E-3) imag = 0.0; System.out.printf(Locale.US, "(%9f,%9f) ", real, imag); } } }
Please provide an equivalent version of this C++ code in Java.
#include <iostream> #include <sstream> typedef long long bigInt; using namespace std; class number { public: number() { s = "0"; neg = false; } number( bigInt a ) { set( a ); } number( string a ) { set( a ); } void set( bigInt a ) { neg = false; if( a < 0 ) { a = -a; neg = true; } ostringstream o; o << a; s = o.str(); clearStr(); } void set( string a ) { neg = false; s = a; if( s.length() > 1 && s[0] == '-' ) { neg = true; } clearStr(); } number operator * ( const number& b ) { return this->mul( b ); } number& operator *= ( const number& b ) { *this = *this * b; return *this; } number& operator = ( const number& b ) { s = b.s; return *this; } friend ostream& operator << ( ostream& out, const number& a ) { if( a.neg ) out << "-"; out << a.s; return out; } friend istream& operator >> ( istream& in, number& a ){ string b; in >> b; a.set( b ); return in; } private: number mul( const number& b ) { number a; bool neg = false; string r, bs = b.s; r.resize( 2 * max( b.s.length(), s.length() ), '0' ); int xx, ss, rr, t, c, stp = 0; string::reverse_iterator xi = bs.rbegin(), si, ri; for( ; xi != bs.rend(); xi++ ) { c = 0; ri = r.rbegin() + stp; for( si = s.rbegin(); si != s.rend(); si++ ) { xx = ( *xi ) - 48; ss = ( *si ) - 48; rr = ( *ri ) - 48; ss = ss * xx + rr + c; t = ss % 10; c = ( ss - t ) / 10; ( *ri++ ) = t + 48; } if( c > 0 ) ( *ri ) = c + 48; stp++; } trimLeft( r ); t = b.neg ? 1 : 0; t += neg ? 1 : 0; if( t & 1 ) a.s = "-" + r; else a.s = r; return a; } void trimLeft( string& r ) { if( r.length() < 2 ) return; for( string::iterator x = r.begin(); x != ( r.end() - 1 ); ) { if( ( *x ) != '0' ) return; x = r.erase( x ); } } void clearStr() { for( string::iterator x = s.begin(); x != s.end(); ) { if( ( *x ) < '0' || ( *x ) > '9' ) x = s.erase( x ); else x++; } } string s; bool neg; }; int main( int argc, char* argv[] ) { number a, b; a.set( "18446744073709551616" ); b.set( "18446744073709551616" ); cout << a * b << endl << endl; cout << "Factor 1 = "; cin >> a; cout << "Factor 2 = "; cin >> b; cout << "Product: = " << a * b << endl << endl; return system( "pause" ); }
public class LongMult { private static byte[] stringToDigits(String num) { byte[] result = new byte[num.length()]; for (int i = 0; i < num.length(); i++) { char c = num.charAt(i); if (c < '0' || c > '9') { throw new IllegalArgumentException("Invalid digit " + c + " found at position " + i); } result[num.length() - 1 - i] = (byte) (c - '0'); } return result; } public static String longMult(String num1, String num2) { byte[] left = stringToDigits(num1); byte[] right = stringToDigits(num2); byte[] result = new byte[left.length + right.length]; for (int rightPos = 0; rightPos < right.length; rightPos++) { byte rightDigit = right[rightPos]; byte temp = 0; for (int leftPos = 0; leftPos < left.length; leftPos++) { temp += result[leftPos + rightPos]; temp += rightDigit * left[leftPos]; result[leftPos + rightPos] = (byte) (temp % 10); temp /= 10; } int destPos = rightPos + left.length; while (temp != 0) { temp += result[destPos] & 0xFFFFFFFFL; result[destPos] = (byte) (temp % 10); temp /= 10; destPos++; } } StringBuilder stringResultBuilder = new StringBuilder(result.length); for (int i = result.length - 1; i >= 0; i--) { byte digit = result[i]; if (digit != 0 || stringResultBuilder.length() > 0) { stringResultBuilder.append((char) (digit + '0')); } } return stringResultBuilder.toString(); } public static void main(String[] args) { System.out.println(longMult("18446744073709551616", "18446744073709551616")); } }
Write the same algorithm in Java as shown in this C++ implementation.
#include <iostream> #include <sstream> typedef long long bigInt; using namespace std; class number { public: number() { s = "0"; neg = false; } number( bigInt a ) { set( a ); } number( string a ) { set( a ); } void set( bigInt a ) { neg = false; if( a < 0 ) { a = -a; neg = true; } ostringstream o; o << a; s = o.str(); clearStr(); } void set( string a ) { neg = false; s = a; if( s.length() > 1 && s[0] == '-' ) { neg = true; } clearStr(); } number operator * ( const number& b ) { return this->mul( b ); } number& operator *= ( const number& b ) { *this = *this * b; return *this; } number& operator = ( const number& b ) { s = b.s; return *this; } friend ostream& operator << ( ostream& out, const number& a ) { if( a.neg ) out << "-"; out << a.s; return out; } friend istream& operator >> ( istream& in, number& a ){ string b; in >> b; a.set( b ); return in; } private: number mul( const number& b ) { number a; bool neg = false; string r, bs = b.s; r.resize( 2 * max( b.s.length(), s.length() ), '0' ); int xx, ss, rr, t, c, stp = 0; string::reverse_iterator xi = bs.rbegin(), si, ri; for( ; xi != bs.rend(); xi++ ) { c = 0; ri = r.rbegin() + stp; for( si = s.rbegin(); si != s.rend(); si++ ) { xx = ( *xi ) - 48; ss = ( *si ) - 48; rr = ( *ri ) - 48; ss = ss * xx + rr + c; t = ss % 10; c = ( ss - t ) / 10; ( *ri++ ) = t + 48; } if( c > 0 ) ( *ri ) = c + 48; stp++; } trimLeft( r ); t = b.neg ? 1 : 0; t += neg ? 1 : 0; if( t & 1 ) a.s = "-" + r; else a.s = r; return a; } void trimLeft( string& r ) { if( r.length() < 2 ) return; for( string::iterator x = r.begin(); x != ( r.end() - 1 ); ) { if( ( *x ) != '0' ) return; x = r.erase( x ); } } void clearStr() { for( string::iterator x = s.begin(); x != s.end(); ) { if( ( *x ) < '0' || ( *x ) > '9' ) x = s.erase( x ); else x++; } } string s; bool neg; }; int main( int argc, char* argv[] ) { number a, b; a.set( "18446744073709551616" ); b.set( "18446744073709551616" ); cout << a * b << endl << endl; cout << "Factor 1 = "; cin >> a; cout << "Factor 2 = "; cin >> b; cout << "Product: = " << a * b << endl << endl; return system( "pause" ); }
public class LongMult { private static byte[] stringToDigits(String num) { byte[] result = new byte[num.length()]; for (int i = 0; i < num.length(); i++) { char c = num.charAt(i); if (c < '0' || c > '9') { throw new IllegalArgumentException("Invalid digit " + c + " found at position " + i); } result[num.length() - 1 - i] = (byte) (c - '0'); } return result; } public static String longMult(String num1, String num2) { byte[] left = stringToDigits(num1); byte[] right = stringToDigits(num2); byte[] result = new byte[left.length + right.length]; for (int rightPos = 0; rightPos < right.length; rightPos++) { byte rightDigit = right[rightPos]; byte temp = 0; for (int leftPos = 0; leftPos < left.length; leftPos++) { temp += result[leftPos + rightPos]; temp += rightDigit * left[leftPos]; result[leftPos + rightPos] = (byte) (temp % 10); temp /= 10; } int destPos = rightPos + left.length; while (temp != 0) { temp += result[destPos] & 0xFFFFFFFFL; result[destPos] = (byte) (temp % 10); temp /= 10; destPos++; } } StringBuilder stringResultBuilder = new StringBuilder(result.length); for (int i = result.length - 1; i >= 0; i--) { byte digit = result[i]; if (digit != 0 || stringResultBuilder.length() > 0) { stringResultBuilder.append((char) (digit + '0')); } } return stringResultBuilder.toString(); } public static void main(String[] args) { System.out.println(longMult("18446744073709551616", "18446744073709551616")); } }
Convert this C++ snippet to Java and keep its semantics consistent.
#include <iomanip> #include <iostream> #include <tuple> std::tuple<uint64_t, uint64_t> solvePell(int n) { int x = (int)sqrt(n); if (x * x == n) { return std::make_pair(1, 0); } int y = x; int z = 1; int r = 2 * x; std::tuple<uint64_t, uint64_t> e = std::make_pair(1, 0); std::tuple<uint64_t, uint64_t> f = std::make_pair(0, 1); uint64_t a = 0; uint64_t b = 0; while (true) { y = r * z - y; z = (n - y * y) / z; r = (x + y) / z; e = std::make_pair(std::get<1>(e), r * std::get<1>(e) + std::get<0>(e)); f = std::make_pair(std::get<1>(f), r * std::get<1>(f) + std::get<0>(f)); a = std::get<1>(e) + x * std::get<1>(f); b = std::get<1>(f); if (a * a - n * b * b == 1) { break; } } return std::make_pair(a, b); } void test(int n) { auto r = solvePell(n); std::cout << "x^2 - " << std::setw(3) << n << " * y^2 = 1 for x = " << std::setw(21) << std::get<0>(r) << " and y = " << std::setw(21) << std::get<1>(r) << '\n'; } int main() { test(61); test(109); test(181); test(277); return 0; }
import java.math.BigInteger; import java.text.NumberFormat; import java.util.ArrayList; import java.util.List; public class PellsEquation { public static void main(String[] args) { NumberFormat format = NumberFormat.getInstance(); for ( int n : new int[] {61, 109, 181, 277, 8941} ) { BigInteger[] pell = pellsEquation(n); System.out.printf("x^2 - %3d * y^2 = 1 for:%n x = %s%n y = %s%n%n", n, format.format(pell[0]), format.format(pell[1])); } } private static final BigInteger[] pellsEquation(int n) { int a0 = (int) Math.sqrt(n); if ( a0*a0 == n ) { throw new IllegalArgumentException("ERROR 102: Invalid n = " + n); } List<Integer> continuedFrac = continuedFraction(n); int count = 0; BigInteger ajm2 = BigInteger.ONE; BigInteger ajm1 = new BigInteger(a0 + ""); BigInteger bjm2 = BigInteger.ZERO; BigInteger bjm1 = BigInteger.ONE; boolean stop = (continuedFrac.size() % 2 == 1); if ( continuedFrac.size() == 2 ) { stop = true; } while ( true ) { count++; BigInteger bn = new BigInteger(continuedFrac.get(count) + ""); BigInteger aj = bn.multiply(ajm1).add(ajm2); BigInteger bj = bn.multiply(bjm1).add(bjm2); if ( stop && (count == continuedFrac.size()-2 || continuedFrac.size() == 2) ) { return new BigInteger[] {aj, bj}; } else if (continuedFrac.size() % 2 == 0 && count == continuedFrac.size()-2 ) { stop = true; } if ( count == continuedFrac.size()-1 ) { count = 0; } ajm2 = ajm1; ajm1 = aj; bjm2 = bjm1; bjm1 = bj; } } private static final List<Integer> continuedFraction(int n) { List<Integer> answer = new ArrayList<Integer>(); int a0 = (int) Math.sqrt(n); answer.add(a0); int a = -a0; int aStart = a; int b = 1; int bStart = b; while ( true ) { int[] values = iterateFrac(n, a, b); answer.add(values[0]); a = values[1]; b = values[2]; if (a == aStart && b == bStart) break; } return answer; } private static final int[] iterateFrac(int n, int a, int b) { int x = (int) Math.floor((b * Math.sqrt(n) - b * a)/(n - a * a)); int[] answer = new int[3]; answer[0] = x; answer[1] = -(b * a + x *(n - a * a)) / b; answer[2] = (n - a * a) / b; return answer; } }
Maintain the same structure and functionality when rewriting this code in Java.
#include <iomanip> #include <iostream> #include <tuple> std::tuple<uint64_t, uint64_t> solvePell(int n) { int x = (int)sqrt(n); if (x * x == n) { return std::make_pair(1, 0); } int y = x; int z = 1; int r = 2 * x; std::tuple<uint64_t, uint64_t> e = std::make_pair(1, 0); std::tuple<uint64_t, uint64_t> f = std::make_pair(0, 1); uint64_t a = 0; uint64_t b = 0; while (true) { y = r * z - y; z = (n - y * y) / z; r = (x + y) / z; e = std::make_pair(std::get<1>(e), r * std::get<1>(e) + std::get<0>(e)); f = std::make_pair(std::get<1>(f), r * std::get<1>(f) + std::get<0>(f)); a = std::get<1>(e) + x * std::get<1>(f); b = std::get<1>(f); if (a * a - n * b * b == 1) { break; } } return std::make_pair(a, b); } void test(int n) { auto r = solvePell(n); std::cout << "x^2 - " << std::setw(3) << n << " * y^2 = 1 for x = " << std::setw(21) << std::get<0>(r) << " and y = " << std::setw(21) << std::get<1>(r) << '\n'; } int main() { test(61); test(109); test(181); test(277); return 0; }
import java.math.BigInteger; import java.text.NumberFormat; import java.util.ArrayList; import java.util.List; public class PellsEquation { public static void main(String[] args) { NumberFormat format = NumberFormat.getInstance(); for ( int n : new int[] {61, 109, 181, 277, 8941} ) { BigInteger[] pell = pellsEquation(n); System.out.printf("x^2 - %3d * y^2 = 1 for:%n x = %s%n y = %s%n%n", n, format.format(pell[0]), format.format(pell[1])); } } private static final BigInteger[] pellsEquation(int n) { int a0 = (int) Math.sqrt(n); if ( a0*a0 == n ) { throw new IllegalArgumentException("ERROR 102: Invalid n = " + n); } List<Integer> continuedFrac = continuedFraction(n); int count = 0; BigInteger ajm2 = BigInteger.ONE; BigInteger ajm1 = new BigInteger(a0 + ""); BigInteger bjm2 = BigInteger.ZERO; BigInteger bjm1 = BigInteger.ONE; boolean stop = (continuedFrac.size() % 2 == 1); if ( continuedFrac.size() == 2 ) { stop = true; } while ( true ) { count++; BigInteger bn = new BigInteger(continuedFrac.get(count) + ""); BigInteger aj = bn.multiply(ajm1).add(ajm2); BigInteger bj = bn.multiply(bjm1).add(bjm2); if ( stop && (count == continuedFrac.size()-2 || continuedFrac.size() == 2) ) { return new BigInteger[] {aj, bj}; } else if (continuedFrac.size() % 2 == 0 && count == continuedFrac.size()-2 ) { stop = true; } if ( count == continuedFrac.size()-1 ) { count = 0; } ajm2 = ajm1; ajm1 = aj; bjm2 = bjm1; bjm1 = bj; } } private static final List<Integer> continuedFraction(int n) { List<Integer> answer = new ArrayList<Integer>(); int a0 = (int) Math.sqrt(n); answer.add(a0); int a = -a0; int aStart = a; int b = 1; int bStart = b; while ( true ) { int[] values = iterateFrac(n, a, b); answer.add(values[0]); a = values[1]; b = values[2]; if (a == aStart && b == bStart) break; } return answer; } private static final int[] iterateFrac(int n, int a, int b) { int x = (int) Math.floor((b * Math.sqrt(n) - b * a)/(n - a * a)); int[] answer = new int[3]; answer[0] = x; answer[1] = -(b * a + x *(n - a * a)) / b; answer[2] = (n - a * a) / b; return answer; } }
Rewrite this program in Java while keeping its functionality equivalent to the C++ version.
#include <iostream> #include <string> #include <algorithm> #include <cstdlib> bool contains_duplicates(std::string s) { std::sort(s.begin(), s.end()); return std::adjacent_find(s.begin(), s.end()) != s.end(); } void game() { typedef std::string::size_type index; std::string symbols = "0123456789"; unsigned int const selection_length = 4; std::random_shuffle(symbols.begin(), symbols.end()); std::string selection = symbols.substr(0, selection_length); std::string guess; while (std::cout << "Your guess? ", std::getline(std::cin, guess)) { if (guess.length() != selection_length || guess.find_first_not_of(symbols) != std::string::npos || contains_duplicates(guess)) { std::cout << guess << " is not a valid guess!"; continue; } unsigned int bulls = 0; unsigned int cows = 0; for (index i = 0; i != selection_length; ++i) { index pos = selection.find(guess[i]); if (pos == i) ++bulls; else if (pos != std::string::npos) ++cows; } std::cout << bulls << " bulls, " << cows << " cows.\n"; if (bulls == selection_length) { std::cout << "Congratulations! You have won!\n"; return; } } std::cerr << "Oops! Something went wrong with input, or you've entered end-of-file!\nExiting ...\n"; std::exit(EXIT_FAILURE); } int main() { std::cout << "Welcome to bulls and cows!\nDo you want to play? "; std::string answer; while (true) { while (true) { if (!std::getline(std::cin, answer)) { std::cout << "I can't get an answer. Exiting.\n"; return EXIT_FAILURE; } if (answer == "yes" || answer == "Yes" || answer == "y" || answer == "Y") break; if (answer == "no" || answer == "No" || answer == "n" || answer == "N") { std::cout << "Ok. Goodbye.\n"; return EXIT_SUCCESS; } std::cout << "Please answer yes or no: "; } game(); std::cout << "Another game? "; } }
import java.util.InputMismatchException; import java.util.Random; import java.util.Scanner; public class BullsAndCows{ public static void main(String[] args){ Random gen= new Random(); int target; while(hasDupes(target= (gen.nextInt(9000) + 1000))); String targetStr = target +""; boolean guessed = false; Scanner input = new Scanner(System.in); int guesses = 0; do{ int bulls = 0; int cows = 0; System.out.print("Guess a 4-digit number with no duplicate digits: "); int guess; try{ guess = input.nextInt(); if(hasDupes(guess) || guess < 1000) continue; }catch(InputMismatchException e){ continue; } guesses++; String guessStr = guess + ""; for(int i= 0;i < 4;i++){ if(guessStr.charAt(i) == targetStr.charAt(i)){ bulls++; }else if(targetStr.contains(guessStr.charAt(i)+"")){ cows++; } } if(bulls == 4){ guessed = true; }else{ System.out.println(cows+" Cows and "+bulls+" Bulls."); } }while(!guessed); System.out.println("You won after "+guesses+" guesses!"); } public static boolean hasDupes(int num){ boolean[] digs = new boolean[10]; while(num > 0){ if(digs[num%10]) return true; digs[num%10] = true; num/= 10; } return false; } }
Write the same code in Java as shown below in C++.
#include <iostream> #include <string> #include <algorithm> #include <cstdlib> bool contains_duplicates(std::string s) { std::sort(s.begin(), s.end()); return std::adjacent_find(s.begin(), s.end()) != s.end(); } void game() { typedef std::string::size_type index; std::string symbols = "0123456789"; unsigned int const selection_length = 4; std::random_shuffle(symbols.begin(), symbols.end()); std::string selection = symbols.substr(0, selection_length); std::string guess; while (std::cout << "Your guess? ", std::getline(std::cin, guess)) { if (guess.length() != selection_length || guess.find_first_not_of(symbols) != std::string::npos || contains_duplicates(guess)) { std::cout << guess << " is not a valid guess!"; continue; } unsigned int bulls = 0; unsigned int cows = 0; for (index i = 0; i != selection_length; ++i) { index pos = selection.find(guess[i]); if (pos == i) ++bulls; else if (pos != std::string::npos) ++cows; } std::cout << bulls << " bulls, " << cows << " cows.\n"; if (bulls == selection_length) { std::cout << "Congratulations! You have won!\n"; return; } } std::cerr << "Oops! Something went wrong with input, or you've entered end-of-file!\nExiting ...\n"; std::exit(EXIT_FAILURE); } int main() { std::cout << "Welcome to bulls and cows!\nDo you want to play? "; std::string answer; while (true) { while (true) { if (!std::getline(std::cin, answer)) { std::cout << "I can't get an answer. Exiting.\n"; return EXIT_FAILURE; } if (answer == "yes" || answer == "Yes" || answer == "y" || answer == "Y") break; if (answer == "no" || answer == "No" || answer == "n" || answer == "N") { std::cout << "Ok. Goodbye.\n"; return EXIT_SUCCESS; } std::cout << "Please answer yes or no: "; } game(); std::cout << "Another game? "; } }
import java.util.InputMismatchException; import java.util.Random; import java.util.Scanner; public class BullsAndCows{ public static void main(String[] args){ Random gen= new Random(); int target; while(hasDupes(target= (gen.nextInt(9000) + 1000))); String targetStr = target +""; boolean guessed = false; Scanner input = new Scanner(System.in); int guesses = 0; do{ int bulls = 0; int cows = 0; System.out.print("Guess a 4-digit number with no duplicate digits: "); int guess; try{ guess = input.nextInt(); if(hasDupes(guess) || guess < 1000) continue; }catch(InputMismatchException e){ continue; } guesses++; String guessStr = guess + ""; for(int i= 0;i < 4;i++){ if(guessStr.charAt(i) == targetStr.charAt(i)){ bulls++; }else if(targetStr.contains(guessStr.charAt(i)+"")){ cows++; } } if(bulls == 4){ guessed = true; }else{ System.out.println(cows+" Cows and "+bulls+" Bulls."); } }while(!guessed); System.out.println("You won after "+guesses+" guesses!"); } public static boolean hasDupes(int num){ boolean[] digs = new boolean[10]; while(num > 0){ if(digs[num%10]) return true; digs[num%10] = true; num/= 10; } return false; } }
Port the provided C++ code into Java while preserving the original functionality.
#include <algorithm> #include <iostream> #include <iterator> template <typename RandomAccessIterator> void bubble_sort(RandomAccessIterator begin, RandomAccessIterator end) { bool swapped = true; while (begin != end-- && swapped) { swapped = false; for (auto i = begin; i != end; ++i) { if (*(i + 1) < *i) { std::iter_swap(i, i + 1); swapped = true; } } } } int main() { int a[] = {100, 2, 56, 200, -52, 3, 99, 33, 177, -199}; bubble_sort(std::begin(a), std::end(a)); copy(std::begin(a), std::end(a), std::ostream_iterator<int>(std::cout, " ")); std::cout << "\n"; }
public static <E extends Comparable<? super E>> void bubbleSort(E[] comparable) { boolean changed = false; do { changed = false; for (int a = 0; a < comparable.length - 1; a++) { if (comparable[a].compareTo(comparable[a + 1]) > 0) { E tmp = comparable[a]; comparable[a] = comparable[a + 1]; comparable[a + 1] = tmp; changed = true; } } } while (changed); }
Write a version of this C++ function in Java with identical behavior.
#include <cmath> #include <iomanip> #include <iostream> unsigned int divisor_count(unsigned int n) { unsigned int total = 1; for (; (n & 1) == 0; n >>= 1) ++total; for (unsigned int p = 3; p * p <= n; p += 2) { unsigned int count = 1; for (; n % p == 0; n /= p) ++count; total *= count; } if (n > 1) total *= 2; return total; } unsigned int divisor_product(unsigned int n) { return static_cast<unsigned int>(std::pow(n, divisor_count(n)/2.0)); } int main() { const unsigned int limit = 50; std::cout << "Product of divisors for the first " << limit << " positive integers:\n"; for (unsigned int n = 1; n <= limit; ++n) { std::cout << std::setw(11) << divisor_product(n); if (n % 5 == 0) std::cout << '\n'; } }
public class ProductOfDivisors { private static long divisorCount(long n) { long total = 1; for (; (n & 1) == 0; n >>= 1) { ++total; } for (long p = 3; p * p <= n; p += 2) { long count = 1; for (; n % p == 0; n /= p) { ++count; } total *= count; } if (n > 1) { total *= 2; } return total; } private static long divisorProduct(long n) { return (long) Math.pow(n, divisorCount(n) / 2.0); } public static void main(String[] args) { final long limit = 50; System.out.printf("Product of divisors for the first %d positive integers:%n", limit); for (long n = 1; n <= limit; n++) { System.out.printf("%11d", divisorProduct(n)); if (n % 5 == 0) { System.out.println(); } } } }
Produce a functionally identical Java code for the snippet given in C++.
#include <cmath> #include <iomanip> #include <iostream> unsigned int divisor_count(unsigned int n) { unsigned int total = 1; for (; (n & 1) == 0; n >>= 1) ++total; for (unsigned int p = 3; p * p <= n; p += 2) { unsigned int count = 1; for (; n % p == 0; n /= p) ++count; total *= count; } if (n > 1) total *= 2; return total; } unsigned int divisor_product(unsigned int n) { return static_cast<unsigned int>(std::pow(n, divisor_count(n)/2.0)); } int main() { const unsigned int limit = 50; std::cout << "Product of divisors for the first " << limit << " positive integers:\n"; for (unsigned int n = 1; n <= limit; ++n) { std::cout << std::setw(11) << divisor_product(n); if (n % 5 == 0) std::cout << '\n'; } }
public class ProductOfDivisors { private static long divisorCount(long n) { long total = 1; for (; (n & 1) == 0; n >>= 1) { ++total; } for (long p = 3; p * p <= n; p += 2) { long count = 1; for (; n % p == 0; n /= p) { ++count; } total *= count; } if (n > 1) { total *= 2; } return total; } private static long divisorProduct(long n) { return (long) Math.pow(n, divisorCount(n) / 2.0); } public static void main(String[] args) { final long limit = 50; System.out.printf("Product of divisors for the first %d positive integers:%n", limit); for (long n = 1; n <= limit; n++) { System.out.printf("%11d", divisorProduct(n)); if (n % 5 == 0) { System.out.println(); } } } }
Rewrite the snippet below in Java so it works the same as the original C++ code.
#include <cmath> #include <iomanip> #include <iostream> unsigned int divisor_count(unsigned int n) { unsigned int total = 1; for (; (n & 1) == 0; n >>= 1) ++total; for (unsigned int p = 3; p * p <= n; p += 2) { unsigned int count = 1; for (; n % p == 0; n /= p) ++count; total *= count; } if (n > 1) total *= 2; return total; } unsigned int divisor_product(unsigned int n) { return static_cast<unsigned int>(std::pow(n, divisor_count(n)/2.0)); } int main() { const unsigned int limit = 50; std::cout << "Product of divisors for the first " << limit << " positive integers:\n"; for (unsigned int n = 1; n <= limit; ++n) { std::cout << std::setw(11) << divisor_product(n); if (n % 5 == 0) std::cout << '\n'; } }
public class ProductOfDivisors { private static long divisorCount(long n) { long total = 1; for (; (n & 1) == 0; n >>= 1) { ++total; } for (long p = 3; p * p <= n; p += 2) { long count = 1; for (; n % p == 0; n /= p) { ++count; } total *= count; } if (n > 1) { total *= 2; } return total; } private static long divisorProduct(long n) { return (long) Math.pow(n, divisorCount(n) / 2.0); } public static void main(String[] args) { final long limit = 50; System.out.printf("Product of divisors for the first %d positive integers:%n", limit); for (long n = 1; n <= limit; n++) { System.out.printf("%11d", divisorProduct(n)); if (n % 5 == 0) { System.out.println(); } } } }
Convert this C++ snippet to Java and keep its semantics consistent.
#include <iostream> #include <fstream> #include <string> using namespace std; int main() { string line; ifstream input ( "input.txt" ); ofstream output ("output.txt"); if (output.is_open()) { if (input.is_open()){ while (getline (input,line)) { output << line << endl; } input.close(); } else { cout << "input.txt cannot be opened!\n"; } output.close(); } else { cout << "output.txt cannot be written to!\n"; } return 0; }
import java.io.*; public class FileIODemo { public static void main(String[] args) { try { FileInputStream in = new FileInputStream("input.txt"); FileOutputStream out = new FileOutputStream("ouput.txt"); int c; while ((c = in.read()) != -1) { out.write(c); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e){ e.printStackTrace(); } } }
Write a version of this C++ function in Java with identical behavior.
#include <iostream> int main() { int a, b; std::cin >> a >> b; std::cout << "a+b = " << a+b << "\n"; std::cout << "a-b = " << a-b << "\n"; std::cout << "a*b = " << a*b << "\n"; std::cout << "a/b = " << a/b << ", remainder " << a%b << "\n"; return 0; }
import java.util.Scanner; public class IntegerArithmetic { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int a = sc.nextInt(); int b = sc.nextInt(); int sum = a + b; int difference = a - b; int product = a * b; int division = a / b; int remainder = a % b; System.out.println("a + b = " + sum); System.out.println("a - b = " + difference); System.out.println("a * b = " + product); System.out.println("quotient of a / b = " + division); System.out.println("remainder of a / b = " + remainder); } }
Rewrite this program in Java while keeping its functionality equivalent to the C++ version.
#include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/io.hpp> int main() { using namespace boost::numeric::ublas; matrix<double> m(3,3); for(int i=0; i!=m.size1(); ++i) for(int j=0; j!=m.size2(); ++j) m(i,j)=3*i+j; std::cout << trans(m) << std::endl; }
import java.util.Arrays; public class Transpose{ public static void main(String[] args){ double[][] m = {{1, 1, 1, 1}, {2, 4, 8, 16}, {3, 9, 27, 81}, {4, 16, 64, 256}, {5, 25, 125, 625}}; double[][] ans = new double[m[0].length][m.length]; for(int rows = 0; rows < m.length; rows++){ for(int cols = 0; cols < m[0].length; cols++){ ans[cols][rows] = m[rows][cols]; } } for(double[] i:ans){ System.out.println(Arrays.toString(i)); } } }
Ensure the translated Java code behaves exactly like the original C++ snippet.
#include <iostream> #include <tr1/memory> using std::tr1::shared_ptr; using std::tr1::enable_shared_from_this; struct Arg { virtual int run() = 0; virtual ~Arg() { }; }; int A(int, shared_ptr<Arg>, shared_ptr<Arg>, shared_ptr<Arg>, shared_ptr<Arg>, shared_ptr<Arg>); class B : public Arg, public enable_shared_from_this<B> { private: int k; const shared_ptr<Arg> x1, x2, x3, x4; public: B(int _k, shared_ptr<Arg> _x1, shared_ptr<Arg> _x2, shared_ptr<Arg> _x3, shared_ptr<Arg> _x4) : k(_k), x1(_x1), x2(_x2), x3(_x3), x4(_x4) { } int run() { return A(--k, shared_from_this(), x1, x2, x3, x4); } }; class Const : public Arg { private: const int x; public: Const(int _x) : x(_x) { } int run () { return x; } }; int A(int k, shared_ptr<Arg> x1, shared_ptr<Arg> x2, shared_ptr<Arg> x3, shared_ptr<Arg> x4, shared_ptr<Arg> x5) { if (k <= 0) return x4->run() + x5->run(); else { shared_ptr<Arg> b(new B(k, x1, x2, x3, x4)); return b->run(); } } int main() { std::cout << A(10, shared_ptr<Arg>(new Const(1)), shared_ptr<Arg>(new Const(-1)), shared_ptr<Arg>(new Const(-1)), shared_ptr<Arg>(new Const(1)), shared_ptr<Arg>(new Const(0))) << std::endl; return 0; }
import java.util.function.DoubleSupplier; public class ManOrBoy { static double A(int k, DoubleSupplier x1, DoubleSupplier x2, DoubleSupplier x3, DoubleSupplier x4, DoubleSupplier x5) { DoubleSupplier B = new DoubleSupplier() { int m = k; public double getAsDouble() { return A(--m, this, x1, x2, x3, x4); } }; return k <= 0 ? x4.getAsDouble() + x5.getAsDouble() : B.getAsDouble(); } public static void main(String[] args) { System.out.println(A(10, () -> 1.0, () -> -1.0, () -> -1.0, () -> 1.0, () -> 0.0)); } }
Write the same code in Java as shown below in C++.
#include <iostream> bool a(bool in) { std::cout << "a" << std::endl; return in; } bool b(bool in) { std::cout << "b" << std::endl; return in; } void test(bool i, bool j) { std::cout << std::boolalpha << i << " and " << j << " = " << (a(i) && b(j)) << std::endl; std::cout << std::boolalpha << i << " or " << j << " = " << (a(i) || b(j)) << std::endl; } int main() { test(false, false); test(false, true); test(true, false); test(true, true); return 0; }
module test { @Inject Console console; static Boolean show(String name, Boolean value) { console.print($"{name}()={value}"); return value; } void run() { val a = show("a", _); val b = show("b", _); for (Boolean v1 : False..True) { for (Boolean v2 : False..True) { console.print($"a({v1}) && b({v2}) == {a(v1) && b(v2)}"); console.print(); console.print($"a({v1}) || b({v2}) == {a(v1) || b(v2)}"); console.print(); } } } }
Ensure the translated Java code behaves exactly like the original C++ snippet.
#include <iostream> void recurse(unsigned int i) { std::cout<<i<<"\n"; recurse(i+1); } int main() { recurse(0); }
public class RecursionTest { private static void recurse(int i) { try { recurse(i+1); } catch (StackOverflowError e) { System.out.print("Recursion depth on this system is " + i + "."); } } public static void main(String[] args) { recurse(0); } }
Write the same algorithm in Java as shown in this C++ implementation.
#include <iostream> void recurse(unsigned int i) { std::cout<<i<<"\n"; recurse(i+1); } int main() { recurse(0); }
public class RecursionTest { private static void recurse(int i) { try { recurse(i+1); } catch (StackOverflowError e) { System.out.print("Recursion depth on this system is " + i + "."); } } public static void main(String[] args) { recurse(0); } }
Change the following C++ code into Java without altering its purpose.
#include <iomanip> #include <iostream> int mod(int n, int d) { return (d + n % d) % d; } bool is_prime(int n) { if (n < 2) return false; if (n % 2 == 0) return n == 2; if (n % 3 == 0) return n == 3; for (int p = 5; p * p <= n; p += 4) { if (n % p == 0) return false; p += 2; if (n % p == 0) return false; } return true; } void print_carmichael_numbers(int prime1) { for (int h3 = 1; h3 < prime1; ++h3) { for (int d = 1; d < h3 + prime1; ++d) { if (mod((h3 + prime1) * (prime1 - 1), d) != 0 || mod(-prime1 * prime1, h3) != mod(d, h3)) continue; int prime2 = 1 + (prime1 - 1) * (h3 + prime1)/d; if (!is_prime(prime2)) continue; int prime3 = 1 + prime1 * prime2/h3; if (!is_prime(prime3)) continue; if (mod(prime2 * prime3, prime1 - 1) != 1) continue; unsigned int c = prime1 * prime2 * prime3; std::cout << std::setw(2) << prime1 << " x " << std::setw(4) << prime2 << " x " << std::setw(5) << prime3 << " = " << std::setw(10) << c << '\n'; } } } int main() { for (int p = 2; p <= 61; ++p) { if (is_prime(p)) print_carmichael_numbers(p); } return 0; }
public class Test { static int mod(int n, int m) { return ((n % m) + m) % m; } static boolean isPrime(int n) { if (n == 2 || n == 3) return true; else if (n < 2 || n % 2 == 0 || n % 3 == 0) return false; for (int div = 5, inc = 2; Math.pow(div, 2) <= n; div += inc, inc = 6 - inc) if (n % div == 0) return false; return true; } public static void main(String[] args) { for (int p = 2; p < 62; p++) { if (!isPrime(p)) continue; for (int h3 = 2; h3 < p; h3++) { int g = h3 + p; for (int d = 1; d < g; d++) { if ((g * (p - 1)) % d != 0 || mod(-p * p, h3) != d % h3) continue; int q = 1 + (p - 1) * g / d; if (!isPrime(q)) continue; int r = 1 + (p * q / h3); if (!isPrime(r) || (q * r) % (p - 1) != 1) continue; System.out.printf("%d x %d x %d%n", p, q, r); } } } } }
Transform the following C++ implementation into Java, maintaining the same output and logic.
#include <windows.h> #include <sstream> #include <tchar.h> using namespace std; const unsigned int BMP_WID = 320, BMP_HEI = 240, WHITE = 16777215, BLACK = 0; class myBitmap { public: myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {} ~myBitmap() { DeleteObject( pen ); DeleteObject( brush ); DeleteDC( hdc ); DeleteObject( bmp ); } bool create( int w, int h ) { BITMAPINFO bi; ZeroMemory( &bi, sizeof( bi ) ); bi.bmiHeader.biSize = sizeof( bi.bmiHeader ); bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8; bi.bmiHeader.biCompression = BI_RGB; bi.bmiHeader.biPlanes = 1; bi.bmiHeader.biWidth = w; bi.bmiHeader.biHeight = -h; HDC dc = GetDC( GetConsoleWindow() ); bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 ); if( !bmp ) return false; hdc = CreateCompatibleDC( dc ); SelectObject( hdc, bmp ); ReleaseDC( GetConsoleWindow(), dc ); width = w; height = h; return true; } void clear( BYTE clr = 0 ) { memset( pBits, clr, width * height * sizeof( DWORD ) ); } void setBrushColor( DWORD bClr ) { if( brush ) DeleteObject( brush ); brush = CreateSolidBrush( bClr ); SelectObject( hdc, brush ); } void setPenColor( DWORD c ) { clr = c; createPen(); } void setPenWidth( int w ) { wid = w; createPen(); } void saveBitmap( string path ) { BITMAPFILEHEADER fileheader; BITMAPINFO infoheader; BITMAP bitmap; DWORD wb; GetObject( bmp, sizeof( bitmap ), &bitmap ); DWORD* dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight]; ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) ); ZeroMemory( &infoheader, sizeof( BITMAPINFO ) ); ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) ); infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8; infoheader.bmiHeader.biCompression = BI_RGB; infoheader.bmiHeader.biPlanes = 1; infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader ); infoheader.bmiHeader.biHeight = bitmap.bmHeight; infoheader.bmiHeader.biWidth = bitmap.bmWidth; infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ); fileheader.bfType = 0x4D42; fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER ); fileheader.bfSize = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage; GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS ); HANDLE file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL ); WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL ); WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL ); WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL ); CloseHandle( file ); delete [] dwpBits; } void* getBits( void ) const { return pBits; } HDC getDC() const { return hdc; } int getWidth() const { return width; } int getHeight() const { return height; } private: void createPen() { if( pen ) DeleteObject( pen ); pen = CreatePen( PS_SOLID, wid, clr ); SelectObject( hdc, pen ); } HBITMAP bmp; HDC hdc; HPEN pen; HBRUSH brush; void* pBits; int width, height, wid; DWORD clr; }; class bmpNoise { public: bmpNoise() { QueryPerformanceFrequency( &_frequency ); _bmp.create( BMP_WID, BMP_HEI ); _frameTime = _fps = 0; _start = getTime(); _frames = 0; } void mainLoop() { float now = getTime(); if( now - _start > 1.0f ) { _fps = static_cast<float>( _frames ) / ( now - _start ); _start = now; _frames = 0; } HDC wdc, dc = _bmp.getDC(); unsigned int* bits = reinterpret_cast<unsigned int*>( _bmp.getBits() ); for( int y = 0; y < BMP_HEI; y++ ) { for( int x = 0; x < BMP_WID; x++ ) { if( rand() % 10 < 5 ) memset( bits, 255, 3 ); else memset( bits, 0, 3 ); bits++; } } ostringstream o; o << _fps; TextOut( dc, 0, 0, o.str().c_str(), o.str().size() ); wdc = GetDC( _hwnd ); BitBlt( wdc, 0, 0, BMP_WID, BMP_HEI, dc, 0, 0, SRCCOPY ); ReleaseDC( _hwnd, wdc ); _frames++; _frameTime = getTime() - now; if( _frameTime > 1.0f ) _frameTime = 1.0f; } void setHWND( HWND hwnd ) { _hwnd = hwnd; } private: float getTime() { LARGE_INTEGER liTime; QueryPerformanceCounter( &liTime ); return liTime.QuadPart / ( float )_frequency.QuadPart; } myBitmap _bmp; HWND _hwnd; float _start, _fps, _frameTime; unsigned int _frames; LARGE_INTEGER _frequency; }; class wnd { public: wnd() { _inst = this; } int wnd::Run( HINSTANCE hInst ) { _hInst = hInst; _hwnd = InitAll(); _noise.setHWND( _hwnd ); ShowWindow( _hwnd, SW_SHOW ); UpdateWindow( _hwnd ); MSG msg; ZeroMemory( &msg, sizeof( msg ) ); while( msg.message != WM_QUIT ) { if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) != 0 ) { TranslateMessage( &msg ); DispatchMessage( &msg ); } else { _noise.mainLoop(); } } return UnregisterClass( "_MY_NOISE_", _hInst ); } private: static int WINAPI wnd::WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ) { switch( msg ) { case WM_DESTROY: PostQuitMessage( 0 ); break; default: return DefWindowProc( hWnd, msg, wParam, lParam ); } return 0; } HWND InitAll() { WNDCLASSEX wcex; ZeroMemory( &wcex, sizeof( wcex ) ); wcex.cbSize = sizeof( WNDCLASSEX ); wcex.style = CS_HREDRAW | CS_VREDRAW; wcex.lpfnWndProc = ( WNDPROC )WndProc; wcex.hInstance = _hInst; wcex.hCursor = LoadCursor( NULL, IDC_ARROW ); wcex.hbrBackground = ( HBRUSH )( COLOR_WINDOW + 1 ); wcex.lpszClassName = "_MY_NOISE_"; RegisterClassEx( &wcex ); RECT rc = { 0, 0, BMP_WID, BMP_HEI }; AdjustWindowRect( &rc, WS_SYSMENU | WS_CAPTION, FALSE ); int w = rc.right - rc.left, h = rc.bottom - rc.top; return CreateWindow( "_MY_NOISE_", ".: Noise image -- PJorente :.", WS_SYSMENU, CW_USEDEFAULT, 0, w, h, NULL, NULL, _hInst, NULL ); } static wnd* _inst; HINSTANCE _hInst; HWND _hwnd; bmpNoise _noise; }; wnd* wnd::_inst = 0; int APIENTRY _tWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow ) { srand( GetTickCount() ); wnd myWnd; return myWnd.Run( hInstance ); }
import java.awt.*; import java.awt.event.*; import java.awt.image.*; import java.util.Arrays; import java.util.Random; import javax.swing.*; public class ImageNoise { int framecount = 0; int fps = 0; BufferedImage image; Kernel kernel; ConvolveOp cop; JFrame frame = new JFrame("Java Image Noise"); JPanel panel = new JPanel() { private int show_fps = 0; private MouseAdapter ma = new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { show_fps = (show_fps + 1) % 3; } }; {addMouseListener(ma);} @Override public Dimension getPreferredSize() { return new Dimension(320, 240); } @Override @SuppressWarnings("fallthrough") public void paintComponent(Graphics g1) { Graphics2D g = (Graphics2D) g1; drawNoise(); g.drawImage(image, 0, 0, null); switch (show_fps) { case 0: int xblur = getWidth() - 130, yblur = getHeight() - 32; BufferedImage bc = image.getSubimage(xblur, yblur, 115, 32); BufferedImage bs = new BufferedImage(bc.getWidth(), bc.getHeight(), BufferedImage.TYPE_BYTE_GRAY); cop.filter(bc, bs); g.drawImage(bs, xblur, yblur , null); case 1: g.setColor(Color.RED); g.setFont(new Font("Monospaced", Font.BOLD, 20)); g.drawString("FPS: " + fps, getWidth() - 120, getHeight() - 10); } framecount++; } }; Timer repainter = new Timer(1, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { panel.repaint(); } }); Timer framerateChecker = new Timer(1000, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { fps = framecount; framecount = 0; } }); public ImageNoise() { float[] vals = new float[121]; Arrays.fill(vals, 1/121f); kernel = new Kernel(11, 11, vals); cop = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null); frame.add(panel); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.pack(); frame.setVisible(true); repainter.start(); framerateChecker.start(); } void drawNoise() { int w = panel.getWidth(), h = panel.getHeight(); if (null == image || image.getWidth() != w || image.getHeight() != h) { image = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY); } Random rand = new Random(); int[] data = new int[w * h]; for (int x = 0; x < w * h / 32; x++) { int r = rand.nextInt(); for (int i = 0; i < 32; i++) { data[x * 32 + i] = (r & 1) * Integer.MAX_VALUE; r >>>= 1; } } image.getRaster().setPixels(0, 0, w, h, data); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { ImageNoise i = new ImageNoise(); } }); } }
Rewrite the snippet below in Java so it works the same as the original C++ code.
#include <windows.h> #include <sstream> #include <tchar.h> using namespace std; const unsigned int BMP_WID = 320, BMP_HEI = 240, WHITE = 16777215, BLACK = 0; class myBitmap { public: myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {} ~myBitmap() { DeleteObject( pen ); DeleteObject( brush ); DeleteDC( hdc ); DeleteObject( bmp ); } bool create( int w, int h ) { BITMAPINFO bi; ZeroMemory( &bi, sizeof( bi ) ); bi.bmiHeader.biSize = sizeof( bi.bmiHeader ); bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8; bi.bmiHeader.biCompression = BI_RGB; bi.bmiHeader.biPlanes = 1; bi.bmiHeader.biWidth = w; bi.bmiHeader.biHeight = -h; HDC dc = GetDC( GetConsoleWindow() ); bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 ); if( !bmp ) return false; hdc = CreateCompatibleDC( dc ); SelectObject( hdc, bmp ); ReleaseDC( GetConsoleWindow(), dc ); width = w; height = h; return true; } void clear( BYTE clr = 0 ) { memset( pBits, clr, width * height * sizeof( DWORD ) ); } void setBrushColor( DWORD bClr ) { if( brush ) DeleteObject( brush ); brush = CreateSolidBrush( bClr ); SelectObject( hdc, brush ); } void setPenColor( DWORD c ) { clr = c; createPen(); } void setPenWidth( int w ) { wid = w; createPen(); } void saveBitmap( string path ) { BITMAPFILEHEADER fileheader; BITMAPINFO infoheader; BITMAP bitmap; DWORD wb; GetObject( bmp, sizeof( bitmap ), &bitmap ); DWORD* dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight]; ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) ); ZeroMemory( &infoheader, sizeof( BITMAPINFO ) ); ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) ); infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8; infoheader.bmiHeader.biCompression = BI_RGB; infoheader.bmiHeader.biPlanes = 1; infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader ); infoheader.bmiHeader.biHeight = bitmap.bmHeight; infoheader.bmiHeader.biWidth = bitmap.bmWidth; infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ); fileheader.bfType = 0x4D42; fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER ); fileheader.bfSize = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage; GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS ); HANDLE file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL ); WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL ); WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL ); WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL ); CloseHandle( file ); delete [] dwpBits; } void* getBits( void ) const { return pBits; } HDC getDC() const { return hdc; } int getWidth() const { return width; } int getHeight() const { return height; } private: void createPen() { if( pen ) DeleteObject( pen ); pen = CreatePen( PS_SOLID, wid, clr ); SelectObject( hdc, pen ); } HBITMAP bmp; HDC hdc; HPEN pen; HBRUSH brush; void* pBits; int width, height, wid; DWORD clr; }; class bmpNoise { public: bmpNoise() { QueryPerformanceFrequency( &_frequency ); _bmp.create( BMP_WID, BMP_HEI ); _frameTime = _fps = 0; _start = getTime(); _frames = 0; } void mainLoop() { float now = getTime(); if( now - _start > 1.0f ) { _fps = static_cast<float>( _frames ) / ( now - _start ); _start = now; _frames = 0; } HDC wdc, dc = _bmp.getDC(); unsigned int* bits = reinterpret_cast<unsigned int*>( _bmp.getBits() ); for( int y = 0; y < BMP_HEI; y++ ) { for( int x = 0; x < BMP_WID; x++ ) { if( rand() % 10 < 5 ) memset( bits, 255, 3 ); else memset( bits, 0, 3 ); bits++; } } ostringstream o; o << _fps; TextOut( dc, 0, 0, o.str().c_str(), o.str().size() ); wdc = GetDC( _hwnd ); BitBlt( wdc, 0, 0, BMP_WID, BMP_HEI, dc, 0, 0, SRCCOPY ); ReleaseDC( _hwnd, wdc ); _frames++; _frameTime = getTime() - now; if( _frameTime > 1.0f ) _frameTime = 1.0f; } void setHWND( HWND hwnd ) { _hwnd = hwnd; } private: float getTime() { LARGE_INTEGER liTime; QueryPerformanceCounter( &liTime ); return liTime.QuadPart / ( float )_frequency.QuadPart; } myBitmap _bmp; HWND _hwnd; float _start, _fps, _frameTime; unsigned int _frames; LARGE_INTEGER _frequency; }; class wnd { public: wnd() { _inst = this; } int wnd::Run( HINSTANCE hInst ) { _hInst = hInst; _hwnd = InitAll(); _noise.setHWND( _hwnd ); ShowWindow( _hwnd, SW_SHOW ); UpdateWindow( _hwnd ); MSG msg; ZeroMemory( &msg, sizeof( msg ) ); while( msg.message != WM_QUIT ) { if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) != 0 ) { TranslateMessage( &msg ); DispatchMessage( &msg ); } else { _noise.mainLoop(); } } return UnregisterClass( "_MY_NOISE_", _hInst ); } private: static int WINAPI wnd::WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ) { switch( msg ) { case WM_DESTROY: PostQuitMessage( 0 ); break; default: return DefWindowProc( hWnd, msg, wParam, lParam ); } return 0; } HWND InitAll() { WNDCLASSEX wcex; ZeroMemory( &wcex, sizeof( wcex ) ); wcex.cbSize = sizeof( WNDCLASSEX ); wcex.style = CS_HREDRAW | CS_VREDRAW; wcex.lpfnWndProc = ( WNDPROC )WndProc; wcex.hInstance = _hInst; wcex.hCursor = LoadCursor( NULL, IDC_ARROW ); wcex.hbrBackground = ( HBRUSH )( COLOR_WINDOW + 1 ); wcex.lpszClassName = "_MY_NOISE_"; RegisterClassEx( &wcex ); RECT rc = { 0, 0, BMP_WID, BMP_HEI }; AdjustWindowRect( &rc, WS_SYSMENU | WS_CAPTION, FALSE ); int w = rc.right - rc.left, h = rc.bottom - rc.top; return CreateWindow( "_MY_NOISE_", ".: Noise image -- PJorente :.", WS_SYSMENU, CW_USEDEFAULT, 0, w, h, NULL, NULL, _hInst, NULL ); } static wnd* _inst; HINSTANCE _hInst; HWND _hwnd; bmpNoise _noise; }; wnd* wnd::_inst = 0; int APIENTRY _tWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow ) { srand( GetTickCount() ); wnd myWnd; return myWnd.Run( hInstance ); }
import java.awt.*; import java.awt.event.*; import java.awt.image.*; import java.util.Arrays; import java.util.Random; import javax.swing.*; public class ImageNoise { int framecount = 0; int fps = 0; BufferedImage image; Kernel kernel; ConvolveOp cop; JFrame frame = new JFrame("Java Image Noise"); JPanel panel = new JPanel() { private int show_fps = 0; private MouseAdapter ma = new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { show_fps = (show_fps + 1) % 3; } }; {addMouseListener(ma);} @Override public Dimension getPreferredSize() { return new Dimension(320, 240); } @Override @SuppressWarnings("fallthrough") public void paintComponent(Graphics g1) { Graphics2D g = (Graphics2D) g1; drawNoise(); g.drawImage(image, 0, 0, null); switch (show_fps) { case 0: int xblur = getWidth() - 130, yblur = getHeight() - 32; BufferedImage bc = image.getSubimage(xblur, yblur, 115, 32); BufferedImage bs = new BufferedImage(bc.getWidth(), bc.getHeight(), BufferedImage.TYPE_BYTE_GRAY); cop.filter(bc, bs); g.drawImage(bs, xblur, yblur , null); case 1: g.setColor(Color.RED); g.setFont(new Font("Monospaced", Font.BOLD, 20)); g.drawString("FPS: " + fps, getWidth() - 120, getHeight() - 10); } framecount++; } }; Timer repainter = new Timer(1, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { panel.repaint(); } }); Timer framerateChecker = new Timer(1000, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { fps = framecount; framecount = 0; } }); public ImageNoise() { float[] vals = new float[121]; Arrays.fill(vals, 1/121f); kernel = new Kernel(11, 11, vals); cop = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null); frame.add(panel); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.pack(); frame.setVisible(true); repainter.start(); framerateChecker.start(); } void drawNoise() { int w = panel.getWidth(), h = panel.getHeight(); if (null == image || image.getWidth() != w || image.getHeight() != h) { image = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY); } Random rand = new Random(); int[] data = new int[w * h]; for (int x = 0; x < w * h / 32; x++) { int r = rand.nextInt(); for (int i = 0; i < 32; i++) { data[x * 32 + i] = (r & 1) * Integer.MAX_VALUE; r >>>= 1; } } image.getRaster().setPixels(0, 0, w, h, data); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { ImageNoise i = new ImageNoise(); } }); } }
Translate this program into Java but keep the logic exactly as in C++.
#include <iostream> using namespace std ; int divisor_sum( int number ) { int sum = 0 ; for ( int i = 1 ; i < number ; i++ ) if ( number % i == 0 ) sum += i ; return sum; } int main( ) { cout << "Perfect numbers from 1 to 33550337:\n" ; for ( int num = 1 ; num < 33550337 ; num++ ) { if (divisor_sum(num) == num) cout << num << '\n' ; } return 0 ; }
public static boolean perf(int n){ int sum= 0; for(int i= 1;i < n;i++){ if(n % i == 0){ sum+= i; } } return sum == n; }
Generate a Java translation of this C++ snippet without changing its computational steps.
#include <iostream> #include <vector> using std::cout; using std::vector; void distribute(int dist, vector<int> &List) { if (dist > List.size() ) List.resize(dist); for (int i=0; i < dist; i++) List[i]++; } vector<int> beadSort(int *myints, int n) { vector<int> list, list2, fifth (myints, myints + n); cout << "#1 Beads falling down: "; for (int i=0; i < fifth.size(); i++) distribute (fifth[i], list); cout << '\n'; cout << "\nBeads on their sides: "; for (int i=0; i < list.size(); i++) cout << " " << list[i]; cout << '\n'; cout << "#2 Beads right side up: "; for (int i=0; i < list.size(); i++) distribute (list[i], list2); cout << '\n'; return list2; } int main() { int myints[] = {734,3,1,24,324,324,32,432,42,3,4,1,1}; vector<int> sorted = beadSort(myints, sizeof(myints)/sizeof(int)); cout << "Sorted list/array: "; for(unsigned int i=0; i<sorted.size(); i++) cout << sorted[i] << ' '; }
public class BeadSort { public static void main(String[] args) { BeadSort now=new BeadSort(); int[] arr=new int[(int)(Math.random()*11)+5]; for(int i=0;i<arr.length;i++) arr[i]=(int)(Math.random()*10); System.out.print("Unsorted: "); now.display1D(arr); int[] sort=now.beadSort(arr); System.out.print("Sorted: "); now.display1D(sort); } int[] beadSort(int[] arr) { int max=a[0]; for(int i=1;i<arr.length;i++) if(arr[i]>max) max=arr[i]; char[][] grid=new char[arr.length][max]; int[] levelcount=new int[max]; for(int i=0;i<max;i++) { levelcount[i]=0; for(int j=0;j<arr.length;j++) grid[j][i]='_'; } for(int i=0;i<arr.length;i++) { int num=arr[i]; for(int j=0;num>0;j++) { grid[levelcount[j]++][j]='*'; num--; } } System.out.println(); display2D(grid); int[] sorted=new int[arr.length]; for(int i=0;i<arr.length;i++) { int putt=0; for(int j=0;j<max&&grid[arr.length-1-i][j]=='*';j++) putt++; sorted[i]=putt; } return sorted; } void display1D(int[] arr) { for(int i=0;i<arr.length;i++) System.out.print(arr[i]+" "); System.out.println(); } void display1D(char[] arr) { for(int i=0;i<arr.length;i++) System.out.print(arr[i]+" "); System.out.println(); } void display2D(char[][] arr) { for(int i=0;i<arr.length;i++) display1D(arr[i]); System.out.println(); } }
Write a version of this C++ function in Java with identical behavior.
#include <array> #include <iostream> template<typename T, size_t S> using FixedSquareGrid = std::array<std::array<T, S>, S>; struct Cistercian { public: Cistercian() { initN(); } Cistercian(int v) { initN(); draw(v); } Cistercian &operator=(int v) { initN(); draw(v); } friend std::ostream &operator<<(std::ostream &, const Cistercian &); private: FixedSquareGrid<char, 15> canvas; void initN() { for (auto &row : canvas) { row.fill(' '); row[5] = 'x'; } } void horizontal(size_t c1, size_t c2, size_t r) { for (size_t c = c1; c <= c2; c++) { canvas[r][c] = 'x'; } } void vertical(size_t r1, size_t r2, size_t c) { for (size_t r = r1; r <= r2; r++) { canvas[r][c] = 'x'; } } void diagd(size_t c1, size_t c2, size_t r) { for (size_t c = c1; c <= c2; c++) { canvas[r + c - c1][c] = 'x'; } } void diagu(size_t c1, size_t c2, size_t r) { for (size_t c = c1; c <= c2; c++) { canvas[r - c + c1][c] = 'x'; } } void drawOnes(int v) { switch (v) { case 1: horizontal(6, 10, 0); break; case 2: horizontal(6, 10, 4); break; case 3: diagd(6, 10, 0); break; case 4: diagu(6, 10, 4); break; case 5: drawOnes(1); drawOnes(4); break; case 6: vertical(0, 4, 10); break; case 7: drawOnes(1); drawOnes(6); break; case 8: drawOnes(2); drawOnes(6); break; case 9: drawOnes(1); drawOnes(8); break; default: break; } } void drawTens(int v) { switch (v) { case 1: horizontal(0, 4, 0); break; case 2: horizontal(0, 4, 4); break; case 3: diagu(0, 4, 4); break; case 4: diagd(0, 4, 0); break; case 5: drawTens(1); drawTens(4); break; case 6: vertical(0, 4, 0); break; case 7: drawTens(1); drawTens(6); break; case 8: drawTens(2); drawTens(6); break; case 9: drawTens(1); drawTens(8); break; default: break; } } void drawHundreds(int hundreds) { switch (hundreds) { case 1: horizontal(6, 10, 14); break; case 2: horizontal(6, 10, 10); break; case 3: diagu(6, 10, 14); break; case 4: diagd(6, 10, 10); break; case 5: drawHundreds(1); drawHundreds(4); break; case 6: vertical(10, 14, 10); break; case 7: drawHundreds(1); drawHundreds(6); break; case 8: drawHundreds(2); drawHundreds(6); break; case 9: drawHundreds(1); drawHundreds(8); break; default: break; } } void drawThousands(int thousands) { switch (thousands) { case 1: horizontal(0, 4, 14); break; case 2: horizontal(0, 4, 10); break; case 3: diagd(0, 4, 10); break; case 4: diagu(0, 4, 14); break; case 5: drawThousands(1); drawThousands(4); break; case 6: vertical(10, 14, 0); break; case 7: drawThousands(1); drawThousands(6); break; case 8: drawThousands(2); drawThousands(6); break; case 9: drawThousands(1); drawThousands(8); break; default: break; } } void draw(int v) { int thousands = v / 1000; v %= 1000; int hundreds = v / 100; v %= 100; int tens = v / 10; int ones = v % 10; if (thousands > 0) { drawThousands(thousands); } if (hundreds > 0) { drawHundreds(hundreds); } if (tens > 0) { drawTens(tens); } if (ones > 0) { drawOnes(ones); } } }; std::ostream &operator<<(std::ostream &os, const Cistercian &c) { for (auto &row : c.canvas) { for (auto cell : row) { os << cell; } os << '\n'; } return os; } int main() { for (auto number : { 0, 1, 20, 300, 4000, 5555, 6789, 9999 }) { std::cout << number << ":\n"; Cistercian c(number); std::cout << c << '\n'; } return 0; }
import java.util.Arrays; import java.util.List; public class Cistercian { private static final int SIZE = 15; private final char[][] canvas = new char[SIZE][SIZE]; public Cistercian(int n) { initN(); draw(n); } public void initN() { for (var row : canvas) { Arrays.fill(row, ' '); row[5] = 'x'; } } private void horizontal(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r][c] = 'x'; } } private void vertical(int r1, int r2, int c) { for (int r = r1; r <= r2; r++) { canvas[r][c] = 'x'; } } private void diagd(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r + c - c1][c] = 'x'; } } private void diagu(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r - c + c1][c] = 'x'; } } private void draw(int v) { var thousands = v / 1000; v %= 1000; var hundreds = v / 100; v %= 100; var tens = v / 10; var ones = v % 10; drawPart(1000 * thousands); drawPart(100 * hundreds); drawPart(10 * tens); drawPart(ones); } private void drawPart(int v) { switch (v) { case 1: horizontal(6, 10, 0); break; case 2: horizontal(6, 10, 4); break; case 3: diagd(6, 10, 0); break; case 4: diagu(6, 10, 4); break; case 5: drawPart(1); drawPart(4); break; case 6: vertical(0, 4, 10); break; case 7: drawPart(1); drawPart(6); break; case 8: drawPart(2); drawPart(6); break; case 9: drawPart(1); drawPart(8); break; case 10: horizontal(0, 4, 0); break; case 20: horizontal(0, 4, 4); break; case 30: diagu(0, 4, 4); break; case 40: diagd(0, 4, 0); break; case 50: drawPart(10); drawPart(40); break; case 60: vertical(0, 4, 0); break; case 70: drawPart(10); drawPart(60); break; case 80: drawPart(20); drawPart(60); break; case 90: drawPart(10); drawPart(80); break; case 100: horizontal(6, 10, 14); break; case 200: horizontal(6, 10, 10); break; case 300: diagu(6, 10, 14); break; case 400: diagd(6, 10, 10); break; case 500: drawPart(100); drawPart(400); break; case 600: vertical(10, 14, 10); break; case 700: drawPart(100); drawPart(600); break; case 800: drawPart(200); drawPart(600); break; case 900: drawPart(100); drawPart(800); break; case 1000: horizontal(0, 4, 14); break; case 2000: horizontal(0, 4, 10); break; case 3000: diagd(0, 4, 10); break; case 4000: diagu(0, 4, 14); break; case 5000: drawPart(1000); drawPart(4000); break; case 6000: vertical(10, 14, 0); break; case 7000: drawPart(1000); drawPart(6000); break; case 8000: drawPart(2000); drawPart(6000); break; case 9000: drawPart(1000); drawPart(8000); break; } } @Override public String toString() { StringBuilder builder = new StringBuilder(); for (var row : canvas) { builder.append(row); builder.append('\n'); } return builder.toString(); } public static void main(String[] args) { for (int number : List.of(0, 1, 20, 300, 4000, 5555, 6789, 9999)) { System.out.printf("%d:\n", number); var c = new Cistercian(number); System.out.println(c); } } }
Preserve the algorithm and functionality while converting the code from C++ to Java.
#include <array> #include <iostream> template<typename T, size_t S> using FixedSquareGrid = std::array<std::array<T, S>, S>; struct Cistercian { public: Cistercian() { initN(); } Cistercian(int v) { initN(); draw(v); } Cistercian &operator=(int v) { initN(); draw(v); } friend std::ostream &operator<<(std::ostream &, const Cistercian &); private: FixedSquareGrid<char, 15> canvas; void initN() { for (auto &row : canvas) { row.fill(' '); row[5] = 'x'; } } void horizontal(size_t c1, size_t c2, size_t r) { for (size_t c = c1; c <= c2; c++) { canvas[r][c] = 'x'; } } void vertical(size_t r1, size_t r2, size_t c) { for (size_t r = r1; r <= r2; r++) { canvas[r][c] = 'x'; } } void diagd(size_t c1, size_t c2, size_t r) { for (size_t c = c1; c <= c2; c++) { canvas[r + c - c1][c] = 'x'; } } void diagu(size_t c1, size_t c2, size_t r) { for (size_t c = c1; c <= c2; c++) { canvas[r - c + c1][c] = 'x'; } } void drawOnes(int v) { switch (v) { case 1: horizontal(6, 10, 0); break; case 2: horizontal(6, 10, 4); break; case 3: diagd(6, 10, 0); break; case 4: diagu(6, 10, 4); break; case 5: drawOnes(1); drawOnes(4); break; case 6: vertical(0, 4, 10); break; case 7: drawOnes(1); drawOnes(6); break; case 8: drawOnes(2); drawOnes(6); break; case 9: drawOnes(1); drawOnes(8); break; default: break; } } void drawTens(int v) { switch (v) { case 1: horizontal(0, 4, 0); break; case 2: horizontal(0, 4, 4); break; case 3: diagu(0, 4, 4); break; case 4: diagd(0, 4, 0); break; case 5: drawTens(1); drawTens(4); break; case 6: vertical(0, 4, 0); break; case 7: drawTens(1); drawTens(6); break; case 8: drawTens(2); drawTens(6); break; case 9: drawTens(1); drawTens(8); break; default: break; } } void drawHundreds(int hundreds) { switch (hundreds) { case 1: horizontal(6, 10, 14); break; case 2: horizontal(6, 10, 10); break; case 3: diagu(6, 10, 14); break; case 4: diagd(6, 10, 10); break; case 5: drawHundreds(1); drawHundreds(4); break; case 6: vertical(10, 14, 10); break; case 7: drawHundreds(1); drawHundreds(6); break; case 8: drawHundreds(2); drawHundreds(6); break; case 9: drawHundreds(1); drawHundreds(8); break; default: break; } } void drawThousands(int thousands) { switch (thousands) { case 1: horizontal(0, 4, 14); break; case 2: horizontal(0, 4, 10); break; case 3: diagd(0, 4, 10); break; case 4: diagu(0, 4, 14); break; case 5: drawThousands(1); drawThousands(4); break; case 6: vertical(10, 14, 0); break; case 7: drawThousands(1); drawThousands(6); break; case 8: drawThousands(2); drawThousands(6); break; case 9: drawThousands(1); drawThousands(8); break; default: break; } } void draw(int v) { int thousands = v / 1000; v %= 1000; int hundreds = v / 100; v %= 100; int tens = v / 10; int ones = v % 10; if (thousands > 0) { drawThousands(thousands); } if (hundreds > 0) { drawHundreds(hundreds); } if (tens > 0) { drawTens(tens); } if (ones > 0) { drawOnes(ones); } } }; std::ostream &operator<<(std::ostream &os, const Cistercian &c) { for (auto &row : c.canvas) { for (auto cell : row) { os << cell; } os << '\n'; } return os; } int main() { for (auto number : { 0, 1, 20, 300, 4000, 5555, 6789, 9999 }) { std::cout << number << ":\n"; Cistercian c(number); std::cout << c << '\n'; } return 0; }
import java.util.Arrays; import java.util.List; public class Cistercian { private static final int SIZE = 15; private final char[][] canvas = new char[SIZE][SIZE]; public Cistercian(int n) { initN(); draw(n); } public void initN() { for (var row : canvas) { Arrays.fill(row, ' '); row[5] = 'x'; } } private void horizontal(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r][c] = 'x'; } } private void vertical(int r1, int r2, int c) { for (int r = r1; r <= r2; r++) { canvas[r][c] = 'x'; } } private void diagd(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r + c - c1][c] = 'x'; } } private void diagu(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r - c + c1][c] = 'x'; } } private void draw(int v) { var thousands = v / 1000; v %= 1000; var hundreds = v / 100; v %= 100; var tens = v / 10; var ones = v % 10; drawPart(1000 * thousands); drawPart(100 * hundreds); drawPart(10 * tens); drawPart(ones); } private void drawPart(int v) { switch (v) { case 1: horizontal(6, 10, 0); break; case 2: horizontal(6, 10, 4); break; case 3: diagd(6, 10, 0); break; case 4: diagu(6, 10, 4); break; case 5: drawPart(1); drawPart(4); break; case 6: vertical(0, 4, 10); break; case 7: drawPart(1); drawPart(6); break; case 8: drawPart(2); drawPart(6); break; case 9: drawPart(1); drawPart(8); break; case 10: horizontal(0, 4, 0); break; case 20: horizontal(0, 4, 4); break; case 30: diagu(0, 4, 4); break; case 40: diagd(0, 4, 0); break; case 50: drawPart(10); drawPart(40); break; case 60: vertical(0, 4, 0); break; case 70: drawPart(10); drawPart(60); break; case 80: drawPart(20); drawPart(60); break; case 90: drawPart(10); drawPart(80); break; case 100: horizontal(6, 10, 14); break; case 200: horizontal(6, 10, 10); break; case 300: diagu(6, 10, 14); break; case 400: diagd(6, 10, 10); break; case 500: drawPart(100); drawPart(400); break; case 600: vertical(10, 14, 10); break; case 700: drawPart(100); drawPart(600); break; case 800: drawPart(200); drawPart(600); break; case 900: drawPart(100); drawPart(800); break; case 1000: horizontal(0, 4, 14); break; case 2000: horizontal(0, 4, 10); break; case 3000: diagd(0, 4, 10); break; case 4000: diagu(0, 4, 14); break; case 5000: drawPart(1000); drawPart(4000); break; case 6000: vertical(10, 14, 0); break; case 7000: drawPart(1000); drawPart(6000); break; case 8000: drawPart(2000); drawPart(6000); break; case 9000: drawPart(1000); drawPart(8000); break; } } @Override public String toString() { StringBuilder builder = new StringBuilder(); for (var row : canvas) { builder.append(row); builder.append('\n'); } return builder.toString(); } public static void main(String[] args) { for (int number : List.of(0, 1, 20, 300, 4000, 5555, 6789, 9999)) { System.out.printf("%d:\n", number); var c = new Cistercian(number); System.out.println(c); } } }