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Can you help me rewrite this code in Go instead of Java, keeping it the same logically?
import java.util.Collections; import java.util.HashMap; import java.util.Map; public class ImmutableMap { public static void main(String[] args) { Map<String,Integer> hashMap = getImmutableMap(); try { hashMap.put("Test", 23); } catch (UnsupportedOperationException e) { System.out.println("ERROR: Unable to put new value."); } try { hashMap.clear(); } catch (UnsupportedOperationException e) { System.out.println("ERROR: Unable to clear map."); } try { hashMap.putIfAbsent("Test", 23); } catch (UnsupportedOperationException e) { System.out.println("ERROR: Unable to put if absent."); } for ( String key : hashMap.keySet() ) { System.out.printf("key = %s, value = %s%n", key, hashMap.get(key)); } } private static Map<String,Integer> getImmutableMap() { Map<String,Integer> hashMap = new HashMap<>(); hashMap.put("Key 1", 34); hashMap.put("Key 2", 105); hashMap.put("Key 3", 144); return Collections.unmodifiableMap(hashMap); } }
package romap type Romap struct{ imap map[byte]int } func New(m map[byte]int) *Romap { if m == nil { return nil } return &Romap{m} } func (rom *Romap) Get(key byte) (int, bool) { i, ok := rom.imap[key] return i, ok } func (rom *Romap) Reset(key byte) { _, ok := rom.imap[key] if ok { rom.imap[key] = 0 } }
Ensure the translated Go code behaves exactly like the original Java snippet.
import java.io.File; import java.nio.file.Files; import java.util.ArrayList; import java.util.Arrays; public class Copypasta { public static void fatal_error(String errtext) { StackTraceElement[] stack = Thread.currentThread().getStackTrace(); StackTraceElement main = stack[stack.length - 1]; String mainClass = main.getClassName(); System.out.println("%" + errtext); System.out.println("usage: " + mainClass + " [filename.cp]"); System.exit(1); } public static void main(String[] args) { String fname = null; String source = null; try { fname = args[0]; source = new String(Files.readAllBytes(new File(fname).toPath())); } catch(Exception e) { fatal_error("error while trying to read from specified file"); } ArrayList<String> lines = new ArrayList<String>(Arrays.asList(source.split("\n"))); String clipboard = ""; int loc = 0; while(loc < lines.size()) { String command = lines.get(loc).trim(); try { if(command.equals("Copy")) clipboard += lines.get(loc + 1); else if(command.equals("CopyFile")) { if(lines.get(loc + 1).equals("TheF*ckingCode")) clipboard += source; else { String filetext = new String(Files.readAllBytes(new File(lines.get(loc + 1)).toPath())); clipboard += filetext; } } else if(command.equals("Duplicate")) { String origClipboard = clipboard; int amount = Integer.parseInt(lines.get(loc + 1)) - 1; for(int i = 0; i < amount; i++) clipboard += origClipboard; } else if(command.equals("Pasta!")) { System.out.println(clipboard); System.exit(0); } else fatal_error("unknown command '" + command + "' encountered on line " + new Integer(loc + 1).toString()); } catch(Exception e) { fatal_error("error while executing command '" + command + "' on line " + new Integer(loc + 1).toString()); } loc += 2; } } }
package main import ( "fmt" "github.com/atotto/clipboard" "io/ioutil" "log" "os" "runtime" "strconv" "strings" ) func check(err error) { if err != nil { clipboard.WriteAll("") log.Fatal(err) } } func interpret(source string) { source2 := source if runtime.GOOS == "windows" { source2 = strings.ReplaceAll(source, "\r\n", "\n") } lines := strings.Split(source2, "\n") le := len(lines) for i := 0; i < le; i++ { lines[i] = strings.TrimSpace(lines[i]) switch lines[i] { case "Copy": if i == le-1 { log.Fatal("There are no lines after the Copy command.") } i++ err := clipboard.WriteAll(lines[i]) check(err) case "CopyFile": if i == le-1 { log.Fatal("There are no lines after the CopyFile command.") } i++ if lines[i] == "TheF*ckingCode" { err := clipboard.WriteAll(source) check(err) } else { bytes, err := ioutil.ReadFile(lines[i]) check(err) err = clipboard.WriteAll(string(bytes)) check(err) } case "Duplicate": if i == le-1 { log.Fatal("There are no lines after the Duplicate command.") } i++ times, err := strconv.Atoi(lines[i]) check(err) if times < 0 { log.Fatal("Can't duplicate text a negative number of times.") } text, err := clipboard.ReadAll() check(err) err = clipboard.WriteAll(strings.Repeat(text, times+1)) check(err) case "Pasta!": text, err := clipboard.ReadAll() check(err) fmt.Println(text) return default: if lines[i] == "" { continue } log.Fatal("Unknown command, " + lines[i]) } } } func main() { if len(os.Args) != 2 { log.Fatal("There should be exactly one command line argument, the CopyPasta file path.") } bytes, err := ioutil.ReadFile(os.Args[1]) check(err) interpret(string(bytes)) err = clipboard.WriteAll("") check(err) }
Keep all operations the same but rewrite the snippet in Go.
import java.math.BigInteger; public class SquareRoot { public static final BigInteger ONE_HUNDRED = BigInteger.valueOf(100); public static final BigInteger TWENTY = BigInteger.valueOf(20); public static void main(String[] args) { var i = BigInteger.TWO; var j = BigInteger.valueOf((long) Math.floor(Math.sqrt(2.0))); var k = j; var d = j; int n = 500; int n0 = n; do { System.out.print(d); i = i.subtract(k.multiply(d)).multiply(ONE_HUNDRED); k = TWENTY.multiply(j); for (d = BigInteger.ONE; d.compareTo(BigInteger.TEN) <= 0; d = d.add(BigInteger.ONE)) { if (k.add(d).multiply(d).compareTo(i) > 0) { d = d.subtract(BigInteger.ONE); break; } } j = j.multiply(BigInteger.TEN).add(d); k = k.add(d); if (n0 > 0) { n--; } } while (n > 0); System.out.println(); } }
package main import ( "fmt" "math/big" ) var one = big.NewInt(1) var ten = big.NewInt(10) var twenty = big.NewInt(20) var hundred = big.NewInt(100) func sqrt(n float64, limit int) { if n < 0 { log.Fatal("Number cannot be negative") } count := 0 for n != math.Trunc(n) { n *= 100 count-- } i := big.NewInt(int64(n)) j := new(big.Int).Sqrt(i) count += len(j.String()) k := new(big.Int).Set(j) d := new(big.Int).Set(j) t := new(big.Int) digits := 0 var sb strings.Builder for digits < limit { sb.WriteString(d.String()) t.Mul(k, d) i.Sub(i, t) i.Mul(i, hundred) k.Mul(j, twenty) d.Set(one) for d.Cmp(ten) <= 0 { t.Add(k, d) t.Mul(t, d) if t.Cmp(i) > 0 { d.Sub(d, one) break } d.Add(d, one) } j.Mul(j, ten) j.Add(j, d) k.Add(k, d) digits = digits + 1 } root := strings.TrimRight(sb.String(), "0") if len(root) == 0 { root = "0" } if count > 0 { root = root[0:count] + "." + root[count:] } else if count == 0 { root = "0." + root } else { root = "0." + strings.Repeat("0", -count) + root } root = strings.TrimSuffix(root, ".") fmt.Println(root) } func main() { numbers := []float64{2, 0.2, 10.89, 625, 0.0001} digits := []int{500, 80, 8, 8, 8} for i, n := range numbers { fmt.Printf("First %d significant digits (at most) of the square root of %g:\n", digits[i], n) sqrt(n, digits[i]) fmt.Println() } }
Change the following Java code into Go without altering its purpose.
import java.math.BigInteger; public class SquareRoot { public static final BigInteger ONE_HUNDRED = BigInteger.valueOf(100); public static final BigInteger TWENTY = BigInteger.valueOf(20); public static void main(String[] args) { var i = BigInteger.TWO; var j = BigInteger.valueOf((long) Math.floor(Math.sqrt(2.0))); var k = j; var d = j; int n = 500; int n0 = n; do { System.out.print(d); i = i.subtract(k.multiply(d)).multiply(ONE_HUNDRED); k = TWENTY.multiply(j); for (d = BigInteger.ONE; d.compareTo(BigInteger.TEN) <= 0; d = d.add(BigInteger.ONE)) { if (k.add(d).multiply(d).compareTo(i) > 0) { d = d.subtract(BigInteger.ONE); break; } } j = j.multiply(BigInteger.TEN).add(d); k = k.add(d); if (n0 > 0) { n--; } } while (n > 0); System.out.println(); } }
package main import ( "fmt" "math/big" ) var one = big.NewInt(1) var ten = big.NewInt(10) var twenty = big.NewInt(20) var hundred = big.NewInt(100) func sqrt(n float64, limit int) { if n < 0 { log.Fatal("Number cannot be negative") } count := 0 for n != math.Trunc(n) { n *= 100 count-- } i := big.NewInt(int64(n)) j := new(big.Int).Sqrt(i) count += len(j.String()) k := new(big.Int).Set(j) d := new(big.Int).Set(j) t := new(big.Int) digits := 0 var sb strings.Builder for digits < limit { sb.WriteString(d.String()) t.Mul(k, d) i.Sub(i, t) i.Mul(i, hundred) k.Mul(j, twenty) d.Set(one) for d.Cmp(ten) <= 0 { t.Add(k, d) t.Mul(t, d) if t.Cmp(i) > 0 { d.Sub(d, one) break } d.Add(d, one) } j.Mul(j, ten) j.Add(j, d) k.Add(k, d) digits = digits + 1 } root := strings.TrimRight(sb.String(), "0") if len(root) == 0 { root = "0" } if count > 0 { root = root[0:count] + "." + root[count:] } else if count == 0 { root = "0." + root } else { root = "0." + strings.Repeat("0", -count) + root } root = strings.TrimSuffix(root, ".") fmt.Println(root) } func main() { numbers := []float64{2, 0.2, 10.89, 625, 0.0001} digits := []int{500, 80, 8, 8, 8} for i, n := range numbers { fmt.Printf("First %d significant digits (at most) of the square root of %g:\n", digits[i], n) sqrt(n, digits[i]) fmt.Println() } }
Preserve the algorithm and functionality while converting the code from Java to Go.
import java.lang.reflect.Field; public class ListFields { public int examplePublicField = 42; private boolean examplePrivateField = true; public static void main(String[] args) throws IllegalAccessException { ListFields obj = new ListFields(); Class clazz = obj.getClass(); System.out.println("All public fields (including inherited):"); for (Field f : clazz.getFields()) { System.out.printf("%s\t%s\n", f, f.get(obj)); } System.out.println(); System.out.println("All declared fields (excluding inherited):"); for (Field f : clazz.getDeclaredFields()) { System.out.printf("%s\t%s\n", f, f.get(obj)); } } }
package main import ( "fmt" "image" "reflect" ) type t struct { X int next *t } func main() { report(t{}) report(image.Point{}) } func report(x interface{}) { t := reflect.TypeOf(x) n := t.NumField() fmt.Printf("Type %v has %d fields:\n", t, n) fmt.Println("Name Type Exported") for i := 0; i < n; i++ { f := t.Field(i) fmt.Printf("%-8s %-8v %-8t\n", f.Name, f.Type, f.PkgPath == "", ) } fmt.Println() }
Translate the given Java code snippet into Go without altering its behavior.
import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class MinimalStepsDownToOne { public static void main(String[] args) { runTasks(getFunctions1()); runTasks(getFunctions2()); runTasks(getFunctions3()); } private static void runTasks(List<Function> functions) { Map<Integer,List<String>> minPath = getInitialMap(functions, 5); int max = 10; populateMap(minPath, functions, max); System.out.printf("%nWith functions: %s%n", functions); System.out.printf(" Minimum steps to 1:%n"); for ( int n = 2 ; n <= max ; n++ ) { int steps = minPath.get(n).size(); System.out.printf(" %2d: %d step%1s: %s%n", n, steps, steps == 1 ? "" : "s", minPath.get(n)); } displayMaxMin(minPath, functions, 2000); displayMaxMin(minPath, functions, 20000); displayMaxMin(minPath, functions, 100000); } private static void displayMaxMin(Map<Integer,List<String>> minPath, List<Function> functions, int max) { populateMap(minPath, functions, max); List<Integer> maxIntegers = getMaxMin(minPath, max); int maxSteps = maxIntegers.remove(0); int numCount = maxIntegers.size(); System.out.printf(" There %s %d number%s in the range 1-%d that have maximum 'minimal steps' of %d:%n %s%n", numCount == 1 ? "is" : "are", numCount, numCount == 1 ? "" : "s", max, maxSteps, maxIntegers); } private static List<Integer> getMaxMin(Map<Integer,List<String>> minPath, int max) { int maxSteps = Integer.MIN_VALUE; List<Integer> maxIntegers = new ArrayList<Integer>(); for ( int n = 2 ; n <= max ; n++ ) { int len = minPath.get(n).size(); if ( len > maxSteps ) { maxSteps = len; maxIntegers.clear(); maxIntegers.add(n); } else if ( len == maxSteps ) { maxIntegers.add(n); } } maxIntegers.add(0, maxSteps); return maxIntegers; } private static void populateMap(Map<Integer,List<String>> minPath, List<Function> functions, int max) { for ( int n = 2 ; n <= max ; n++ ) { if ( minPath.containsKey(n) ) { continue; } Function minFunction = null; int minSteps = Integer.MAX_VALUE; for ( Function f : functions ) { if ( f.actionOk(n) ) { int result = f.action(n); int steps = 1 + minPath.get(result).size(); if ( steps < minSteps ) { minFunction = f; minSteps = steps; } } } int result = minFunction.action(n); List<String> path = new ArrayList<String>(); path.add(minFunction.toString(n)); path.addAll(minPath.get(result)); minPath.put(n, path); } } private static Map<Integer,List<String>> getInitialMap(List<Function> functions, int max) { Map<Integer,List<String>> minPath = new HashMap<>(); for ( int i = 2 ; i <= max ; i++ ) { for ( Function f : functions ) { if ( f.actionOk(i) ) { int result = f.action(i); if ( result == 1 ) { List<String> path = new ArrayList<String>(); path.add(f.toString(i)); minPath.put(i, path); } } } } return minPath; } private static List<Function> getFunctions3() { List<Function> functions = new ArrayList<>(); functions.add(new Divide2Function()); functions.add(new Divide3Function()); functions.add(new Subtract2Function()); functions.add(new Subtract1Function()); return functions; } private static List<Function> getFunctions2() { List<Function> functions = new ArrayList<>(); functions.add(new Divide3Function()); functions.add(new Divide2Function()); functions.add(new Subtract2Function()); return functions; } private static List<Function> getFunctions1() { List<Function> functions = new ArrayList<>(); functions.add(new Divide3Function()); functions.add(new Divide2Function()); functions.add(new Subtract1Function()); return functions; } public abstract static class Function { abstract public int action(int n); abstract public boolean actionOk(int n); abstract public String toString(int n); } public static class Divide2Function extends Function { @Override public int action(int n) { return n/2; } @Override public boolean actionOk(int n) { return n % 2 == 0; } @Override public String toString(int n) { return "/2 -> " + n/2; } @Override public String toString() { return "Divisor 2"; } } public static class Divide3Function extends Function { @Override public int action(int n) { return n/3; } @Override public boolean actionOk(int n) { return n % 3 == 0; } @Override public String toString(int n) { return "/3 -> " + n/3; } @Override public String toString() { return "Divisor 3"; } } public static class Subtract1Function extends Function { @Override public int action(int n) { return n-1; } @Override public boolean actionOk(int n) { return true; } @Override public String toString(int n) { return "-1 -> " + (n-1); } @Override public String toString() { return "Subtractor 1"; } } public static class Subtract2Function extends Function { @Override public int action(int n) { return n-2; } @Override public boolean actionOk(int n) { return n > 2; } @Override public String toString(int n) { return "-2 -> " + (n-2); } @Override public String toString() { return "Subtractor 2"; } } }
package main import ( "fmt" "strings" ) const limit = 50000 var ( divs, subs []int mins [][]string ) func minsteps(n int) { if n == 1 { mins[1] = []string{} return } min := limit var p, q int var op byte for _, div := range divs { if n%div == 0 { d := n / div steps := len(mins[d]) + 1 if steps < min { min = steps p, q, op = d, div, '/' } } } for _, sub := range subs { if d := n - sub; d >= 1 { steps := len(mins[d]) + 1 if steps < min { min = steps p, q, op = d, sub, '-' } } } mins[n] = append(mins[n], fmt.Sprintf("%c%d -> %d", op, q, p)) mins[n] = append(mins[n], mins[p]...) } func main() { for r := 0; r < 2; r++ { divs = []int{2, 3} if r == 0 { subs = []int{1} } else { subs = []int{2} } mins = make([][]string, limit+1) fmt.Printf("With: Divisors: %v, Subtractors: %v =>\n", divs, subs) fmt.Println(" Minimum number of steps to diminish the following numbers down to 1 is:") for i := 1; i <= limit; i++ { minsteps(i) if i <= 10 { steps := len(mins[i]) plural := "s" if steps == 1 { plural = " " } fmt.Printf(" %2d: %d step%s: %s\n", i, steps, plural, strings.Join(mins[i], ", ")) } } for _, lim := range []int{2000, 20000, 50000} { max := 0 for _, min := range mins[0 : lim+1] { m := len(min) if m > max { max = m } } var maxs []int for i, min := range mins[0 : lim+1] { if len(min) == max { maxs = append(maxs, i) } } nums := len(maxs) verb, verb2, plural := "are", "have", "s" if nums == 1 { verb, verb2, plural = "is", "has", "" } fmt.Printf(" There %s %d number%s in the range 1-%d ", verb, nums, plural, lim) fmt.Printf("that %s maximum 'minimal steps' of %d:\n", verb2, max) fmt.Println(" ", maxs) } fmt.Println() } }
Write a version of this Java function in Go with identical behavior.
import java.io.IOException; import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.nio.file.Paths; import java.util.ArrayList; import java.util.List; import org.apache.commons.lang3.StringUtils; public class ColumnAligner { private List<String[]> words = new ArrayList<>(); private int columns = 0; private List<Integer> columnWidths = new ArrayList<>(); public ColumnAligner(String s) { String[] lines = s.split("\\n"); for (String line : lines) { processInputLine(line); } } public ColumnAligner(List<String> lines) { for (String line : lines) { processInputLine(line); } } private void processInputLine(String line) { String[] lineWords = line.split("\\$"); words.add(lineWords); columns = Math.max(columns, lineWords.length); for (int i = 0; i < lineWords.length; i++) { String word = lineWords[i]; if (i >= columnWidths.size()) { columnWidths.add(word.length()); } else { columnWidths.set(i, Math.max(columnWidths.get(i), word.length())); } } } interface AlignFunction { String align(String s, int length); } public String alignLeft() { return align(new AlignFunction() { @Override public String align(String s, int length) { return StringUtils.rightPad(s, length); } }); } public String alignRight() { return align(new AlignFunction() { @Override public String align(String s, int length) { return StringUtils.leftPad(s, length); } }); } public String alignCenter() { return align(new AlignFunction() { @Override public String align(String s, int length) { return StringUtils.center(s, length); } }); } private String align(AlignFunction a) { StringBuilder result = new StringBuilder(); for (String[] lineWords : words) { for (int i = 0; i < lineWords.length; i++) { String word = lineWords[i]; if (i == 0) { result.append("|"); } result.append(a.align(word, columnWidths.get(i)) + "|"); } result.append("\n"); } return result.toString(); } public static void main(String args[]) throws IOException { if (args.length < 1) { System.out.println("Usage: ColumnAligner file [left|right|center]"); return; } String filePath = args[0]; String alignment = "left"; if (args.length >= 2) { alignment = args[1]; } ColumnAligner ca = new ColumnAligner(Files.readAllLines(Paths.get(filePath), StandardCharsets.UTF_8)); switch (alignment) { case "left": System.out.print(ca.alignLeft()); break; case "right": System.out.print(ca.alignRight()); break; case "center": System.out.print(ca.alignCenter()); break; default: System.err.println(String.format("Error! Unknown alignment: '%s'", alignment)); break; } } }
package main import ( "fmt" "strings" ) const text = `Given$a$text$file$of$many$lines,$where$fields$within$a$line$ are$delineated$by$a$single$'dollar'$character,$write$a$program that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$ column$are$separated$by$at$least$one$space. Further,$allow$for$each$word$in$a$column$to$be$either$left$ justified,$right$justified,$or$center$justified$within$its$column.` type formatter struct { text [][]string width []int } func newFormatter(text string) *formatter { var f formatter for _, line := range strings.Split(text, "\n") { words := strings.Split(line, "$") for words[len(words)-1] == "" { words = words[:len(words)-1] } f.text = append(f.text, words) for i, word := range words { if i == len(f.width) { f.width = append(f.width, len(word)) } else if len(word) > f.width[i] { f.width[i] = len(word) } } } return &f } const ( left = iota middle right ) func (f formatter) print(j int) { for _, line := range f.text { for i, word := range line { fmt.Printf("%-*s ", f.width[i], fmt.Sprintf("%*s", len(word)+(f.width[i]-len(word))*j/2, word)) } fmt.Println("") } fmt.Println("") } func main() { f := newFormatter(text) f.print(left) f.print(middle) f.print(right) }
Convert this Java snippet to Go and keep its semantics consistent.
import java.net.URI; import java.net.URISyntaxException; public class WebAddressParser{ public static void main(String[] args){ parseAddress("foo: parseAddress("urn:example:animal:ferret:nose"); } static void parseAddress(String a){ System.out.println("Parsing " + a); try{ URI u = new URI(a); System.out.println("\tscheme = " + u.getScheme()); System.out.println("\tdomain = " + u.getHost()); System.out.println("\tport = " + (-1==u.getPort()?"default":u.getPort())); System.out.println("\tpath = " + (null==u.getPath()?u.getSchemeSpecificPart():u.getPath())); System.out.println("\tquery = " + u.getQuery()); System.out.println("\tfragment = " + u.getFragment()); } catch (URISyntaxException x){ System.err.println("Oops: " + x); } } }
package main import ( "fmt" "log" "net" "net/url" ) func main() { for _, in := range []string{ "foo: "urn:example:animal:ferret:nose", "jdbc:mysql: "ftp: "http: "ldap: "mailto:John.Doe@example.com", "news:comp.infosystems.www.servers.unix", "tel:+1-816-555-1212", "telnet: "urn:oasis:names:specification:docbook:dtd:xml:4.1.2", "ssh: "https: "http: } { fmt.Println(in) u, err := url.Parse(in) if err != nil { log.Println(err) continue } if in != u.String() { fmt.Printf("Note: reassmebles as %q\n", u) } printURL(u) } } func printURL(u *url.URL) { fmt.Println(" Scheme:", u.Scheme) if u.Opaque != "" { fmt.Println(" Opaque:", u.Opaque) } if u.User != nil { fmt.Println(" Username:", u.User.Username()) if pwd, ok := u.User.Password(); ok { fmt.Println(" Password:", pwd) } } if u.Host != "" { if host, port, err := net.SplitHostPort(u.Host); err == nil { fmt.Println(" Host:", host) fmt.Println(" Port:", port) } else { fmt.Println(" Host:", u.Host) } } if u.Path != "" { fmt.Println(" Path:", u.Path) } if u.RawQuery != "" { fmt.Println(" RawQuery:", u.RawQuery) m, err := url.ParseQuery(u.RawQuery) if err == nil { for k, v := range m { fmt.Printf(" Key: %q Values: %q\n", k, v) } } } if u.Fragment != "" { fmt.Println(" Fragment:", u.Fragment) } }
Can you help me rewrite this code in Go instead of Java, keeping it the same logically?
import java.net.URI; import java.net.URISyntaxException; public class WebAddressParser{ public static void main(String[] args){ parseAddress("foo: parseAddress("urn:example:animal:ferret:nose"); } static void parseAddress(String a){ System.out.println("Parsing " + a); try{ URI u = new URI(a); System.out.println("\tscheme = " + u.getScheme()); System.out.println("\tdomain = " + u.getHost()); System.out.println("\tport = " + (-1==u.getPort()?"default":u.getPort())); System.out.println("\tpath = " + (null==u.getPath()?u.getSchemeSpecificPart():u.getPath())); System.out.println("\tquery = " + u.getQuery()); System.out.println("\tfragment = " + u.getFragment()); } catch (URISyntaxException x){ System.err.println("Oops: " + x); } } }
package main import ( "fmt" "log" "net" "net/url" ) func main() { for _, in := range []string{ "foo: "urn:example:animal:ferret:nose", "jdbc:mysql: "ftp: "http: "ldap: "mailto:John.Doe@example.com", "news:comp.infosystems.www.servers.unix", "tel:+1-816-555-1212", "telnet: "urn:oasis:names:specification:docbook:dtd:xml:4.1.2", "ssh: "https: "http: } { fmt.Println(in) u, err := url.Parse(in) if err != nil { log.Println(err) continue } if in != u.String() { fmt.Printf("Note: reassmebles as %q\n", u) } printURL(u) } } func printURL(u *url.URL) { fmt.Println(" Scheme:", u.Scheme) if u.Opaque != "" { fmt.Println(" Opaque:", u.Opaque) } if u.User != nil { fmt.Println(" Username:", u.User.Username()) if pwd, ok := u.User.Password(); ok { fmt.Println(" Password:", pwd) } } if u.Host != "" { if host, port, err := net.SplitHostPort(u.Host); err == nil { fmt.Println(" Host:", host) fmt.Println(" Port:", port) } else { fmt.Println(" Host:", u.Host) } } if u.Path != "" { fmt.Println(" Path:", u.Path) } if u.RawQuery != "" { fmt.Println(" RawQuery:", u.RawQuery) m, err := url.ParseQuery(u.RawQuery) if err == nil { for k, v := range m { fmt.Printf(" Key: %q Values: %q\n", k, v) } } } if u.Fragment != "" { fmt.Println(" Fragment:", u.Fragment) } }
Produce a language-to-language conversion: from Java to Go, same semantics.
import java.math.BigInteger; import java.util.List; public class Base58CheckEncoding { private static final String ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"; private static final BigInteger BIG0 = BigInteger.ZERO; private static final BigInteger BIG58 = BigInteger.valueOf(58); private static String convertToBase58(String hash) { return convertToBase58(hash, 16); } private static String convertToBase58(String hash, int base) { BigInteger x; if (base == 16 && hash.substring(0, 2).equals("0x")) { x = new BigInteger(hash.substring(2), 16); } else { x = new BigInteger(hash, base); } StringBuilder sb = new StringBuilder(); while (x.compareTo(BIG0) > 0) { int r = x.mod(BIG58).intValue(); sb.append(ALPHABET.charAt(r)); x = x.divide(BIG58); } return sb.reverse().toString(); } public static void main(String[] args) { String s = "25420294593250030202636073700053352635053786165627414518"; String b = convertToBase58(s, 10); System.out.printf("%s -> %s\n", s, b); List<String> hashes = List.of( "0x61", "0x626262", "0x636363", "0x73696d706c792061206c6f6e6720737472696e67", "0x516b6fcd0f", "0xbf4f89001e670274dd", "0x572e4794", "0xecac89cad93923c02321", "0x10c8511e" ); for (String hash : hashes) { String b58 = convertToBase58(hash); System.out.printf("%-56s -> %s\n", hash, b58); } } }
package main import ( "fmt" "log" "math/big" "strings" ) const alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz" var big0 = new(big.Int) var big58 = big.NewInt(58) func reverse(s string) string { r := []rune(s) for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 { r[i], r[j] = r[j], r[i] } return string(r) } func convertToBase58(hash string, base int) (string, error) { var x, ok = new(big.Int).SetString(hash, base) if !ok { return "", fmt.Errorf("'%v' is not a valid integer in base '%d'", hash, base) } var sb strings.Builder var rem = new(big.Int) for x.Cmp(big0) == 1 { x.QuoRem(x, big58, rem) r := rem.Int64() sb.WriteByte(alphabet[r]) } return reverse(sb.String()), nil } func main() { s := "25420294593250030202636073700053352635053786165627414518" b, err := convertToBase58(s, 10) if err != nil { log.Fatal(err) } fmt.Println(s, "->", b) hashes := [...]string{ "0x61", "0x626262", "0x636363", "0x73696d706c792061206c6f6e6720737472696e67", "0x516b6fcd0f", "0xbf4f89001e670274dd", "0x572e4794", "0xecac89cad93923c02321", "0x10c8511e", } for _, hash := range hashes { b58, err := convertToBase58(hash, 0) if err != nil { log.Fatal(err) } fmt.Printf("%-56s -> %s\n", hash, b58) } }
Change the programming language of this snippet from Java to Go without modifying what it does.
import java.math.BigInteger; import java.util.List; public class Base58CheckEncoding { private static final String ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"; private static final BigInteger BIG0 = BigInteger.ZERO; private static final BigInteger BIG58 = BigInteger.valueOf(58); private static String convertToBase58(String hash) { return convertToBase58(hash, 16); } private static String convertToBase58(String hash, int base) { BigInteger x; if (base == 16 && hash.substring(0, 2).equals("0x")) { x = new BigInteger(hash.substring(2), 16); } else { x = new BigInteger(hash, base); } StringBuilder sb = new StringBuilder(); while (x.compareTo(BIG0) > 0) { int r = x.mod(BIG58).intValue(); sb.append(ALPHABET.charAt(r)); x = x.divide(BIG58); } return sb.reverse().toString(); } public static void main(String[] args) { String s = "25420294593250030202636073700053352635053786165627414518"; String b = convertToBase58(s, 10); System.out.printf("%s -> %s\n", s, b); List<String> hashes = List.of( "0x61", "0x626262", "0x636363", "0x73696d706c792061206c6f6e6720737472696e67", "0x516b6fcd0f", "0xbf4f89001e670274dd", "0x572e4794", "0xecac89cad93923c02321", "0x10c8511e" ); for (String hash : hashes) { String b58 = convertToBase58(hash); System.out.printf("%-56s -> %s\n", hash, b58); } } }
package main import ( "fmt" "log" "math/big" "strings" ) const alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz" var big0 = new(big.Int) var big58 = big.NewInt(58) func reverse(s string) string { r := []rune(s) for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 { r[i], r[j] = r[j], r[i] } return string(r) } func convertToBase58(hash string, base int) (string, error) { var x, ok = new(big.Int).SetString(hash, base) if !ok { return "", fmt.Errorf("'%v' is not a valid integer in base '%d'", hash, base) } var sb strings.Builder var rem = new(big.Int) for x.Cmp(big0) == 1 { x.QuoRem(x, big58, rem) r := rem.Int64() sb.WriteByte(alphabet[r]) } return reverse(sb.String()), nil } func main() { s := "25420294593250030202636073700053352635053786165627414518" b, err := convertToBase58(s, 10) if err != nil { log.Fatal(err) } fmt.Println(s, "->", b) hashes := [...]string{ "0x61", "0x626262", "0x636363", "0x73696d706c792061206c6f6e6720737472696e67", "0x516b6fcd0f", "0xbf4f89001e670274dd", "0x572e4794", "0xecac89cad93923c02321", "0x10c8511e", } for _, hash := range hashes { b58, err := convertToBase58(hash, 0) if err != nil { log.Fatal(err) } fmt.Printf("%-56s -> %s\n", hash, b58) } }
Can you help me rewrite this code in Go instead of Java, keeping it the same logically?
public static void main(String... args){ HashMap<String, Integer> vars = new HashMap<String, Integer>(); vars.put("Variable name", 3); vars.put("Next variable name", 5); Scanner sc = new Scanner(System.in); String str = sc.next(); vars.put(str, sc.nextInt()); System.out.println(vars.get("Variable name")); System.out.println(vars.get(str)); }
package main import ( "bufio" "fmt" "log" "os" "strconv" "strings" ) func check(err error) { if err != nil { log.Fatal(err) } } func main() { scanner := bufio.NewScanner(os.Stdin) n := 0 for n < 1 || n > 5 { fmt.Print("How many integer variables do you want to create (max 5) : ") scanner.Scan() n, _ = strconv.Atoi(scanner.Text()) check(scanner.Err()) } vars := make(map[string]int) fmt.Println("OK, enter the variable names and their values, below") for i := 1; i <= n; { fmt.Println("\n Variable", i) fmt.Print(" Name  : ") scanner.Scan() name := scanner.Text() check(scanner.Err()) if _, ok := vars[name]; ok { fmt.Println(" Sorry, you've already created a variable of that name, try again") continue } var value int var err error for { fmt.Print(" Value : ") scanner.Scan() value, err = strconv.Atoi(scanner.Text()) check(scanner.Err()) if err != nil { fmt.Println(" Not a valid integer, try again") } else { break } } vars[name] = value i++ } fmt.Println("\nEnter q to quit") for { fmt.Print("\nWhich variable do you want to inspect : ") scanner.Scan() name := scanner.Text() check(scanner.Err()) if s := strings.ToLower(name); s == "q" { return } v, ok := vars[name] if !ok { fmt.Println("Sorry there's no variable of that name, try again") } else { fmt.Println("It's value is", v) } } }
Change the following Java code into Go without altering its purpose.
public static void main(String... args){ HashMap<String, Integer> vars = new HashMap<String, Integer>(); vars.put("Variable name", 3); vars.put("Next variable name", 5); Scanner sc = new Scanner(System.in); String str = sc.next(); vars.put(str, sc.nextInt()); System.out.println(vars.get("Variable name")); System.out.println(vars.get(str)); }
package main import ( "bufio" "fmt" "log" "os" "strconv" "strings" ) func check(err error) { if err != nil { log.Fatal(err) } } func main() { scanner := bufio.NewScanner(os.Stdin) n := 0 for n < 1 || n > 5 { fmt.Print("How many integer variables do you want to create (max 5) : ") scanner.Scan() n, _ = strconv.Atoi(scanner.Text()) check(scanner.Err()) } vars := make(map[string]int) fmt.Println("OK, enter the variable names and their values, below") for i := 1; i <= n; { fmt.Println("\n Variable", i) fmt.Print(" Name  : ") scanner.Scan() name := scanner.Text() check(scanner.Err()) if _, ok := vars[name]; ok { fmt.Println(" Sorry, you've already created a variable of that name, try again") continue } var value int var err error for { fmt.Print(" Value : ") scanner.Scan() value, err = strconv.Atoi(scanner.Text()) check(scanner.Err()) if err != nil { fmt.Println(" Not a valid integer, try again") } else { break } } vars[name] = value i++ } fmt.Println("\nEnter q to quit") for { fmt.Print("\nWhich variable do you want to inspect : ") scanner.Scan() name := scanner.Text() check(scanner.Err()) if s := strings.ToLower(name); s == "q" { return } v, ok := vars[name] if !ok { fmt.Println("Sorry there's no variable of that name, try again") } else { fmt.Println("It's value is", v) } } }
Write the same algorithm in Go as shown in this Java implementation.
import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; public class DataEncryptionStandard { private static byte[] toHexByteArray(String self) { byte[] bytes = new byte[self.length() / 2]; for (int i = 0; i < bytes.length; ++i) { bytes[i] = ((byte) Integer.parseInt(self.substring(i * 2, i * 2 + 2), 16)); } return bytes; } private static void printHexBytes(byte[] self, String label) { System.out.printf("%s: ", label); for (byte b : self) { int bb = (b >= 0) ? ((int) b) : b + 256; String ts = Integer.toString(bb, 16); if (ts.length() < 2) { ts = "0" + ts; } System.out.print(ts); } System.out.println(); } public static void main(String[] args) throws Exception { String strKey = "0e329232ea6d0d73"; byte[] keyBytes = toHexByteArray(strKey); SecretKeySpec key = new SecretKeySpec(keyBytes, "DES"); Cipher encCipher = Cipher.getInstance("DES"); encCipher.init(Cipher.ENCRYPT_MODE, key); String strPlain = "8787878787878787"; byte[] plainBytes = toHexByteArray(strPlain); byte[] encBytes = encCipher.doFinal(plainBytes); printHexBytes(encBytes, "Encoded"); Cipher decCipher = Cipher.getInstance("DES"); decCipher.init(Cipher.DECRYPT_MODE, key); byte[] decBytes = decCipher.doFinal(encBytes); printHexBytes(decBytes, "Decoded"); } }
package main import ( "crypto/des" "encoding/hex" "fmt" "log" ) func main() { key, err := hex.DecodeString("0e329232ea6d0d73") if err != nil { log.Fatal(err) } c, err := des.NewCipher(key) if err != nil { log.Fatal(err) } src, err := hex.DecodeString("8787878787878787") if err != nil { log.Fatal(err) } dst := make([]byte, des.BlockSize) c.Encrypt(dst, src) fmt.Printf("%x\n", dst) }
Write a version of this Java function in Go with identical behavior.
import java.math.BigInteger; import java.util.Arrays; public class FibonacciMatrixExponentiation { public static void main(String[] args) { BigInteger mod = BigInteger.TEN.pow(20); for ( int exp : Arrays.asList(32, 64) ) { System.out.printf("Last 20 digits of fib(2^%d) = %s%n", exp, fibMod(BigInteger.valueOf(2).pow(exp), mod)); } for ( int i = 1 ; i <= 7 ; i++ ) { BigInteger n = BigInteger.TEN.pow(i); System.out.printf("fib(%,d) = %s%n", n, displayFib(fib(n))); } } private static String displayFib(BigInteger fib) { String s = fib.toString(); if ( s.length() <= 40 ) { return s; } return s.substring(0, 20) + " ... " + s.subSequence(s.length()-20, s.length()); } private static BigInteger fib(BigInteger k) { BigInteger aRes = BigInteger.ZERO; BigInteger bRes = BigInteger.ONE; BigInteger cRes = BigInteger.ONE; BigInteger aBase = BigInteger.ZERO; BigInteger bBase = BigInteger.ONE; BigInteger cBase = BigInteger.ONE; while ( k.compareTo(BigInteger.ZERO) > 0 ) { if ( k.mod(BigInteger.valueOf(2)).compareTo(BigInteger.ONE) == 0 ) { BigInteger temp1 = aRes.multiply(aBase).add(bRes.multiply(bBase)); BigInteger temp2 = aBase.multiply(bRes).add(bBase.multiply(cRes)); BigInteger temp3 = bBase.multiply(bRes).add(cBase.multiply(cRes)); aRes = temp1; bRes = temp2; cRes = temp3; } k = k.shiftRight(1); BigInteger temp1 = aBase.multiply(aBase).add(bBase.multiply(bBase)); BigInteger temp2 = aBase.multiply(bBase).add(bBase.multiply(cBase)); BigInteger temp3 = bBase.multiply(bBase).add(cBase.multiply(cBase)); aBase = temp1; bBase = temp2; cBase = temp3; } return aRes; } private static BigInteger fibMod(BigInteger k, BigInteger mod) { BigInteger aRes = BigInteger.ZERO; BigInteger bRes = BigInteger.ONE; BigInteger cRes = BigInteger.ONE; BigInteger aBase = BigInteger.ZERO; BigInteger bBase = BigInteger.ONE; BigInteger cBase = BigInteger.ONE; while ( k.compareTo(BigInteger.ZERO) > 0 ) { if ( k.mod(BigInteger.valueOf(2)).compareTo(BigInteger.ONE) == 0 ) { BigInteger temp1 = aRes.multiply(aBase).add(bRes.multiply(bBase)).mod(mod); BigInteger temp2 = aBase.multiply(bRes).add(bBase.multiply(cRes)).mod(mod); BigInteger temp3 = bBase.multiply(bRes).add(cBase.multiply(cRes)).mod(mod); aRes = temp1; bRes = temp2; cRes = temp3; } k = k.shiftRight(1); BigInteger temp1 = aBase.multiply(aBase).add(bBase.multiply(bBase)).mod(mod); BigInteger temp2 = aBase.multiply(bBase).add(bBase.multiply(cBase)).mod(mod); BigInteger temp3 = bBase.multiply(bBase).add(cBase.multiply(cBase)).mod(mod); aBase = temp1; bBase = temp2; cBase = temp3; } return aRes.mod(mod); } }
package main import ( "fmt" big "github.com/ncw/gmp" "time" ) type vector = []*big.Int type matrix []vector var ( zero = new(big.Int) one = big.NewInt(1) ) func (m1 matrix) mul(m2 matrix) matrix { rows1, cols1 := len(m1), len(m1[0]) rows2, cols2 := len(m2), len(m2[0]) if cols1 != rows2 { panic("Matrices cannot be multiplied.") } result := make(matrix, rows1) temp := new(big.Int) for i := 0; i < rows1; i++ { result[i] = make(vector, cols2) for j := 0; j < cols2; j++ { result[i][j] = new(big.Int) for k := 0; k < rows2; k++ { temp.Mul(m1[i][k], m2[k][j]) result[i][j].Add(result[i][j], temp) } } } return result } func identityMatrix(n uint64) matrix { if n < 1 { panic("Size of identity matrix can't be less than 1") } ident := make(matrix, n) for i := uint64(0); i < n; i++ { ident[i] = make(vector, n) for j := uint64(0); j < n; j++ { ident[i][j] = new(big.Int) if i == j { ident[i][j].Set(one) } } } return ident } func (m matrix) pow(n *big.Int) matrix { le := len(m) if le != len(m[0]) { panic("Not a square matrix") } switch { case n.Cmp(zero) == -1: panic("Negative exponents not supported") case n.Cmp(zero) == 0: return identityMatrix(uint64(le)) case n.Cmp(one) == 0: return m } pow := identityMatrix(uint64(le)) base := m e := new(big.Int).Set(n) temp := new(big.Int) for e.Cmp(zero) > 0 { temp.And(e, one) if temp.Cmp(one) == 0 { pow = pow.mul(base) } e.Rsh(e, 1) base = base.mul(base) } return pow } func fibonacci(n *big.Int) *big.Int { if n.Cmp(zero) == 0 { return zero } m := matrix{{one, one}, {one, zero}} m = m.pow(n.Sub(n, one)) return m[0][0] } func commatize(n uint64) string { s := fmt.Sprintf("%d", n) le := len(s) for i := le - 3; i >= 1; i -= 3 { s = s[0:i] + "," + s[i:] } return s } func main() { start := time.Now() n := new(big.Int) for i := uint64(10); i <= 1e7; i *= 10 { n.SetUint64(i) s := fibonacci(n).String() fmt.Printf("The digits of the %sth Fibonacci number (%s) are:\n", commatize(i), commatize(uint64(len(s)))) if len(s) > 20 { fmt.Printf(" First 20 : %s\n", s[0:20]) if len(s) < 40 { fmt.Printf(" Final %-2d : %s\n", len(s)-20, s[20:]) } else { fmt.Printf(" Final 20 : %s\n", s[len(s)-20:]) } } else { fmt.Printf(" All %-2d  : %s\n", len(s), s) } fmt.Println() } sfxs := []string{"nd", "th"} for i, e := range []uint{16, 32} { n.Lsh(one, e) s := fibonacci(n).String() fmt.Printf("The digits of the 2^%d%s Fibonacci number (%s) are:\n", e, sfxs[i], commatize(uint64(len(s)))) fmt.Printf(" First 20 : %s\n", s[0:20]) fmt.Printf(" Final 20 : %s\n", s[len(s)-20:]) fmt.Println() } fmt.Printf("Took %s\n\n", time.Since(start)) }
Convert this Java snippet to Go and keep its semantics consistent.
import java.math.BigInteger; import java.util.Arrays; public class FibonacciMatrixExponentiation { public static void main(String[] args) { BigInteger mod = BigInteger.TEN.pow(20); for ( int exp : Arrays.asList(32, 64) ) { System.out.printf("Last 20 digits of fib(2^%d) = %s%n", exp, fibMod(BigInteger.valueOf(2).pow(exp), mod)); } for ( int i = 1 ; i <= 7 ; i++ ) { BigInteger n = BigInteger.TEN.pow(i); System.out.printf("fib(%,d) = %s%n", n, displayFib(fib(n))); } } private static String displayFib(BigInteger fib) { String s = fib.toString(); if ( s.length() <= 40 ) { return s; } return s.substring(0, 20) + " ... " + s.subSequence(s.length()-20, s.length()); } private static BigInteger fib(BigInteger k) { BigInteger aRes = BigInteger.ZERO; BigInteger bRes = BigInteger.ONE; BigInteger cRes = BigInteger.ONE; BigInteger aBase = BigInteger.ZERO; BigInteger bBase = BigInteger.ONE; BigInteger cBase = BigInteger.ONE; while ( k.compareTo(BigInteger.ZERO) > 0 ) { if ( k.mod(BigInteger.valueOf(2)).compareTo(BigInteger.ONE) == 0 ) { BigInteger temp1 = aRes.multiply(aBase).add(bRes.multiply(bBase)); BigInteger temp2 = aBase.multiply(bRes).add(bBase.multiply(cRes)); BigInteger temp3 = bBase.multiply(bRes).add(cBase.multiply(cRes)); aRes = temp1; bRes = temp2; cRes = temp3; } k = k.shiftRight(1); BigInteger temp1 = aBase.multiply(aBase).add(bBase.multiply(bBase)); BigInteger temp2 = aBase.multiply(bBase).add(bBase.multiply(cBase)); BigInteger temp3 = bBase.multiply(bBase).add(cBase.multiply(cBase)); aBase = temp1; bBase = temp2; cBase = temp3; } return aRes; } private static BigInteger fibMod(BigInteger k, BigInteger mod) { BigInteger aRes = BigInteger.ZERO; BigInteger bRes = BigInteger.ONE; BigInteger cRes = BigInteger.ONE; BigInteger aBase = BigInteger.ZERO; BigInteger bBase = BigInteger.ONE; BigInteger cBase = BigInteger.ONE; while ( k.compareTo(BigInteger.ZERO) > 0 ) { if ( k.mod(BigInteger.valueOf(2)).compareTo(BigInteger.ONE) == 0 ) { BigInteger temp1 = aRes.multiply(aBase).add(bRes.multiply(bBase)).mod(mod); BigInteger temp2 = aBase.multiply(bRes).add(bBase.multiply(cRes)).mod(mod); BigInteger temp3 = bBase.multiply(bRes).add(cBase.multiply(cRes)).mod(mod); aRes = temp1; bRes = temp2; cRes = temp3; } k = k.shiftRight(1); BigInteger temp1 = aBase.multiply(aBase).add(bBase.multiply(bBase)).mod(mod); BigInteger temp2 = aBase.multiply(bBase).add(bBase.multiply(cBase)).mod(mod); BigInteger temp3 = bBase.multiply(bBase).add(cBase.multiply(cBase)).mod(mod); aBase = temp1; bBase = temp2; cBase = temp3; } return aRes.mod(mod); } }
package main import ( "fmt" big "github.com/ncw/gmp" "time" ) type vector = []*big.Int type matrix []vector var ( zero = new(big.Int) one = big.NewInt(1) ) func (m1 matrix) mul(m2 matrix) matrix { rows1, cols1 := len(m1), len(m1[0]) rows2, cols2 := len(m2), len(m2[0]) if cols1 != rows2 { panic("Matrices cannot be multiplied.") } result := make(matrix, rows1) temp := new(big.Int) for i := 0; i < rows1; i++ { result[i] = make(vector, cols2) for j := 0; j < cols2; j++ { result[i][j] = new(big.Int) for k := 0; k < rows2; k++ { temp.Mul(m1[i][k], m2[k][j]) result[i][j].Add(result[i][j], temp) } } } return result } func identityMatrix(n uint64) matrix { if n < 1 { panic("Size of identity matrix can't be less than 1") } ident := make(matrix, n) for i := uint64(0); i < n; i++ { ident[i] = make(vector, n) for j := uint64(0); j < n; j++ { ident[i][j] = new(big.Int) if i == j { ident[i][j].Set(one) } } } return ident } func (m matrix) pow(n *big.Int) matrix { le := len(m) if le != len(m[0]) { panic("Not a square matrix") } switch { case n.Cmp(zero) == -1: panic("Negative exponents not supported") case n.Cmp(zero) == 0: return identityMatrix(uint64(le)) case n.Cmp(one) == 0: return m } pow := identityMatrix(uint64(le)) base := m e := new(big.Int).Set(n) temp := new(big.Int) for e.Cmp(zero) > 0 { temp.And(e, one) if temp.Cmp(one) == 0 { pow = pow.mul(base) } e.Rsh(e, 1) base = base.mul(base) } return pow } func fibonacci(n *big.Int) *big.Int { if n.Cmp(zero) == 0 { return zero } m := matrix{{one, one}, {one, zero}} m = m.pow(n.Sub(n, one)) return m[0][0] } func commatize(n uint64) string { s := fmt.Sprintf("%d", n) le := len(s) for i := le - 3; i >= 1; i -= 3 { s = s[0:i] + "," + s[i:] } return s } func main() { start := time.Now() n := new(big.Int) for i := uint64(10); i <= 1e7; i *= 10 { n.SetUint64(i) s := fibonacci(n).String() fmt.Printf("The digits of the %sth Fibonacci number (%s) are:\n", commatize(i), commatize(uint64(len(s)))) if len(s) > 20 { fmt.Printf(" First 20 : %s\n", s[0:20]) if len(s) < 40 { fmt.Printf(" Final %-2d : %s\n", len(s)-20, s[20:]) } else { fmt.Printf(" Final 20 : %s\n", s[len(s)-20:]) } } else { fmt.Printf(" All %-2d  : %s\n", len(s), s) } fmt.Println() } sfxs := []string{"nd", "th"} for i, e := range []uint{16, 32} { n.Lsh(one, e) s := fibonacci(n).String() fmt.Printf("The digits of the 2^%d%s Fibonacci number (%s) are:\n", e, sfxs[i], commatize(uint64(len(s)))) fmt.Printf(" First 20 : %s\n", s[0:20]) fmt.Printf(" Final 20 : %s\n", s[len(s)-20:]) fmt.Println() } fmt.Printf("Took %s\n\n", time.Since(start)) }
Write the same algorithm in Go as shown in this Java implementation.
import java.math.BigInteger; import java.util.Arrays; public class FibonacciMatrixExponentiation { public static void main(String[] args) { BigInteger mod = BigInteger.TEN.pow(20); for ( int exp : Arrays.asList(32, 64) ) { System.out.printf("Last 20 digits of fib(2^%d) = %s%n", exp, fibMod(BigInteger.valueOf(2).pow(exp), mod)); } for ( int i = 1 ; i <= 7 ; i++ ) { BigInteger n = BigInteger.TEN.pow(i); System.out.printf("fib(%,d) = %s%n", n, displayFib(fib(n))); } } private static String displayFib(BigInteger fib) { String s = fib.toString(); if ( s.length() <= 40 ) { return s; } return s.substring(0, 20) + " ... " + s.subSequence(s.length()-20, s.length()); } private static BigInteger fib(BigInteger k) { BigInteger aRes = BigInteger.ZERO; BigInteger bRes = BigInteger.ONE; BigInteger cRes = BigInteger.ONE; BigInteger aBase = BigInteger.ZERO; BigInteger bBase = BigInteger.ONE; BigInteger cBase = BigInteger.ONE; while ( k.compareTo(BigInteger.ZERO) > 0 ) { if ( k.mod(BigInteger.valueOf(2)).compareTo(BigInteger.ONE) == 0 ) { BigInteger temp1 = aRes.multiply(aBase).add(bRes.multiply(bBase)); BigInteger temp2 = aBase.multiply(bRes).add(bBase.multiply(cRes)); BigInteger temp3 = bBase.multiply(bRes).add(cBase.multiply(cRes)); aRes = temp1; bRes = temp2; cRes = temp3; } k = k.shiftRight(1); BigInteger temp1 = aBase.multiply(aBase).add(bBase.multiply(bBase)); BigInteger temp2 = aBase.multiply(bBase).add(bBase.multiply(cBase)); BigInteger temp3 = bBase.multiply(bBase).add(cBase.multiply(cBase)); aBase = temp1; bBase = temp2; cBase = temp3; } return aRes; } private static BigInteger fibMod(BigInteger k, BigInteger mod) { BigInteger aRes = BigInteger.ZERO; BigInteger bRes = BigInteger.ONE; BigInteger cRes = BigInteger.ONE; BigInteger aBase = BigInteger.ZERO; BigInteger bBase = BigInteger.ONE; BigInteger cBase = BigInteger.ONE; while ( k.compareTo(BigInteger.ZERO) > 0 ) { if ( k.mod(BigInteger.valueOf(2)).compareTo(BigInteger.ONE) == 0 ) { BigInteger temp1 = aRes.multiply(aBase).add(bRes.multiply(bBase)).mod(mod); BigInteger temp2 = aBase.multiply(bRes).add(bBase.multiply(cRes)).mod(mod); BigInteger temp3 = bBase.multiply(bRes).add(cBase.multiply(cRes)).mod(mod); aRes = temp1; bRes = temp2; cRes = temp3; } k = k.shiftRight(1); BigInteger temp1 = aBase.multiply(aBase).add(bBase.multiply(bBase)).mod(mod); BigInteger temp2 = aBase.multiply(bBase).add(bBase.multiply(cBase)).mod(mod); BigInteger temp3 = bBase.multiply(bBase).add(cBase.multiply(cBase)).mod(mod); aBase = temp1; bBase = temp2; cBase = temp3; } return aRes.mod(mod); } }
package main import ( "fmt" big "github.com/ncw/gmp" "time" ) type vector = []*big.Int type matrix []vector var ( zero = new(big.Int) one = big.NewInt(1) ) func (m1 matrix) mul(m2 matrix) matrix { rows1, cols1 := len(m1), len(m1[0]) rows2, cols2 := len(m2), len(m2[0]) if cols1 != rows2 { panic("Matrices cannot be multiplied.") } result := make(matrix, rows1) temp := new(big.Int) for i := 0; i < rows1; i++ { result[i] = make(vector, cols2) for j := 0; j < cols2; j++ { result[i][j] = new(big.Int) for k := 0; k < rows2; k++ { temp.Mul(m1[i][k], m2[k][j]) result[i][j].Add(result[i][j], temp) } } } return result } func identityMatrix(n uint64) matrix { if n < 1 { panic("Size of identity matrix can't be less than 1") } ident := make(matrix, n) for i := uint64(0); i < n; i++ { ident[i] = make(vector, n) for j := uint64(0); j < n; j++ { ident[i][j] = new(big.Int) if i == j { ident[i][j].Set(one) } } } return ident } func (m matrix) pow(n *big.Int) matrix { le := len(m) if le != len(m[0]) { panic("Not a square matrix") } switch { case n.Cmp(zero) == -1: panic("Negative exponents not supported") case n.Cmp(zero) == 0: return identityMatrix(uint64(le)) case n.Cmp(one) == 0: return m } pow := identityMatrix(uint64(le)) base := m e := new(big.Int).Set(n) temp := new(big.Int) for e.Cmp(zero) > 0 { temp.And(e, one) if temp.Cmp(one) == 0 { pow = pow.mul(base) } e.Rsh(e, 1) base = base.mul(base) } return pow } func fibonacci(n *big.Int) *big.Int { if n.Cmp(zero) == 0 { return zero } m := matrix{{one, one}, {one, zero}} m = m.pow(n.Sub(n, one)) return m[0][0] } func commatize(n uint64) string { s := fmt.Sprintf("%d", n) le := len(s) for i := le - 3; i >= 1; i -= 3 { s = s[0:i] + "," + s[i:] } return s } func main() { start := time.Now() n := new(big.Int) for i := uint64(10); i <= 1e7; i *= 10 { n.SetUint64(i) s := fibonacci(n).String() fmt.Printf("The digits of the %sth Fibonacci number (%s) are:\n", commatize(i), commatize(uint64(len(s)))) if len(s) > 20 { fmt.Printf(" First 20 : %s\n", s[0:20]) if len(s) < 40 { fmt.Printf(" Final %-2d : %s\n", len(s)-20, s[20:]) } else { fmt.Printf(" Final 20 : %s\n", s[len(s)-20:]) } } else { fmt.Printf(" All %-2d  : %s\n", len(s), s) } fmt.Println() } sfxs := []string{"nd", "th"} for i, e := range []uint{16, 32} { n.Lsh(one, e) s := fibonacci(n).String() fmt.Printf("The digits of the 2^%d%s Fibonacci number (%s) are:\n", e, sfxs[i], commatize(uint64(len(s)))) fmt.Printf(" First 20 : %s\n", s[0:20]) fmt.Printf(" Final 20 : %s\n", s[len(s)-20:]) fmt.Println() } fmt.Printf("Took %s\n\n", time.Since(start)) }
Can you help me rewrite this code in Go instead of Java, keeping it the same logically?
import java.io.File; import java.util.*; import java.util.regex.*; public class CommatizingNumbers { public static void main(String[] args) throws Exception { commatize("pi=3.14159265358979323846264338327950288419716939937510582" + "097494459231", 6, 5, " "); commatize("The author has two Z$100000000000000 Zimbabwe notes (100 " + "trillion).", 0, 3, "."); try (Scanner sc = new Scanner(new File("input.txt"))) { while(sc.hasNext()) commatize(sc.nextLine()); } } static void commatize(String s) { commatize(s, 0, 3, ","); } static void commatize(String s, int start, int step, String ins) { if (start < 0 || start > s.length() || step < 1 || step > s.length()) return; Matcher m = Pattern.compile("([1-9][0-9]*)").matcher(s.substring(start)); StringBuffer result = new StringBuffer(s.substring(0, start)); if (m.find()) { StringBuilder sb = new StringBuilder(m.group(1)).reverse(); for (int i = step; i < sb.length(); i += step) sb.insert(i++, ins); m.appendReplacement(result, sb.reverse().toString()); } System.out.println(m.appendTail(result)); } }
package main import ( "fmt" "regexp" "strings" ) var reg = regexp.MustCompile(`(\.[0-9]+|[1-9]([0-9]+)?(\.[0-9]+)?)`) func reverse(s string) string { r := []rune(s) for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 { r[i], r[j] = r[j], r[i] } return string(r) } func commatize(s string, startIndex, period int, sep string) string { if startIndex < 0 || startIndex >= len(s) || period < 1 || sep == "" { return s } m := reg.FindString(s[startIndex:]) if m == "" { return s } splits := strings.Split(m, ".") ip := splits[0] if len(ip) > period { pi := reverse(ip) for i := (len(ip) - 1) / period * period; i >= period; i -= period { pi = pi[:i] + sep + pi[i:] } ip = reverse(pi) } if strings.Contains(m, ".") { dp := splits[1] if len(dp) > period { for i := (len(dp) - 1) / period * period; i >= period; i -= period { dp = dp[:i] + sep + dp[i:] } } ip += "." + dp } return s[:startIndex] + strings.Replace(s[startIndex:], m, ip, 1) } func main() { tests := [...]string{ "123456789.123456789", ".123456789", "57256.1D-4", "pi=3.14159265358979323846264338327950288419716939937510582097494459231", "The author has two Z$100000000000000 Zimbabwe notes (100 trillion).", "-in Aus$+1411.8millions", "===US$0017440 millions=== (in 2000 dollars)", "123.e8000 is pretty big.", "The land area of the earth is 57268900(29% of the surface) square miles.", "Ain't no numbers in this here words, nohow, no way, Jose.", "James was never known as 0000000007", "Arthur Eddington wrote: I believe there are " + "15747724136275002577605653961181555468044717914527116709366231425076185631031296" + " protons in the universe.", " $-140000±100 millions.", "6/9/1946 was a good year for some.", } fmt.Println(commatize(tests[0], 0, 2, "*")) fmt.Println(commatize(tests[1], 0, 3, "-")) fmt.Println(commatize(tests[2], 0, 4, "__")) fmt.Println(commatize(tests[3], 0, 5, " ")) fmt.Println(commatize(tests[4], 0, 3, ".")) for _, test := range tests[5:] { fmt.Println(commatize(test, 0, 3, ",")) } }
Rewrite this program in Go while keeping its functionality equivalent to the Java version.
import java.math.BigInteger; import java.util.HashMap; import java.util.Map; import java.util.Objects; public class ArithmeticCoding { private static class Triple<A, B, C> { A a; B b; C c; Triple(A a, B b, C c) { this.a = a; this.b = b; this.c = c; } } private static class Freq extends HashMap<Character, Long> { } private static Freq cumulativeFreq(Freq freq) { long total = 0; Freq cf = new Freq(); for (int i = 0; i < 256; ++i) { char c = (char) i; Long v = freq.get(c); if (v != null) { cf.put(c, total); total += v; } } return cf; } private static Triple<BigInteger, Integer, Freq> arithmeticCoding(String str, Long radix) { char[] chars = str.toCharArray(); Freq freq = new Freq(); for (char c : chars) { if (!freq.containsKey(c)) freq.put(c, 1L); else freq.put(c, freq.get(c) + 1); } Freq cf = cumulativeFreq(freq); BigInteger base = BigInteger.valueOf(chars.length); BigInteger lower = BigInteger.ZERO; BigInteger pf = BigInteger.ONE; for (char c : chars) { BigInteger x = BigInteger.valueOf(cf.get(c)); lower = lower.multiply(base).add(x.multiply(pf)); pf = pf.multiply(BigInteger.valueOf(freq.get(c))); } BigInteger upper = lower.add(pf); int powr = 0; BigInteger bigRadix = BigInteger.valueOf(radix); while (true) { pf = pf.divide(bigRadix); if (pf.equals(BigInteger.ZERO)) break; powr++; } BigInteger diff = upper.subtract(BigInteger.ONE).divide(bigRadix.pow(powr)); return new Triple<>(diff, powr, freq); } private static String arithmeticDecoding(BigInteger num, long radix, int pwr, Freq freq) { BigInteger powr = BigInteger.valueOf(radix); BigInteger enc = num.multiply(powr.pow(pwr)); long base = 0; for (Long v : freq.values()) base += v; Freq cf = cumulativeFreq(freq); Map<Long, Character> dict = new HashMap<>(); for (Map.Entry<Character, Long> entry : cf.entrySet()) dict.put(entry.getValue(), entry.getKey()); long lchar = -1; for (long i = 0; i < base; ++i) { Character v = dict.get(i); if (v != null) { lchar = v; } else if (lchar != -1) { dict.put(i, (char) lchar); } } StringBuilder decoded = new StringBuilder((int) base); BigInteger bigBase = BigInteger.valueOf(base); for (long i = base - 1; i >= 0; --i) { BigInteger pow = bigBase.pow((int) i); BigInteger div = enc.divide(pow); Character c = dict.get(div.longValue()); BigInteger fv = BigInteger.valueOf(freq.get(c)); BigInteger cv = BigInteger.valueOf(cf.get(c)); BigInteger diff = enc.subtract(pow.multiply(cv)); enc = diff.divide(fv); decoded.append(c); } return decoded.toString(); } public static void main(String[] args) { long radix = 10; String[] strings = {"DABDDB", "DABDDBBDDBA", "ABRACADABRA", "TOBEORNOTTOBEORTOBEORNOT"}; String fmt = "%-25s=> %19s * %d^%s\n"; for (String str : strings) { Triple<BigInteger, Integer, Freq> encoded = arithmeticCoding(str, radix); String dec = arithmeticDecoding(encoded.a, radix, encoded.b, encoded.c); System.out.printf(fmt, str, encoded.a, radix, encoded.b); if (!Objects.equals(str, dec)) throw new RuntimeException("\tHowever that is incorrect!"); } } }
package main import ( "fmt" "math/big" ) func cumulative_freq(freq map[byte]int64) map[byte]int64 { total := int64(0) cf := make(map[byte]int64) for i := 0; i < 256; i++ { b := byte(i) if v, ok := freq[b]; ok { cf[b] = total total += v } } return cf } func arithmethic_coding(str string, radix int64) (*big.Int, *big.Int, map[byte]int64) { chars := []byte(str) freq := make(map[byte]int64) for _, c := range chars { freq[c] += 1 } cf := cumulative_freq(freq) base := len(chars) L := big.NewInt(0) pf := big.NewInt(1) bigBase := big.NewInt(int64(base)) for _, c := range chars { x := big.NewInt(cf[c]) L.Mul(L, bigBase) L.Add(L, x.Mul(x, pf)) pf.Mul(pf, big.NewInt(freq[c])) } U := big.NewInt(0) U.Set(L) U.Add(U, pf) bigOne := big.NewInt(1) bigZero := big.NewInt(0) bigRadix := big.NewInt(radix) tmp := big.NewInt(0).Set(pf) powr := big.NewInt(0) for { tmp.Div(tmp, bigRadix) if tmp.Cmp(bigZero) == 0 { break } powr.Add(powr, bigOne) } diff := big.NewInt(0) diff.Sub(U, bigOne) diff.Div(diff, big.NewInt(0).Exp(bigRadix, powr, nil)) return diff, powr, freq } func arithmethic_decoding(num *big.Int, radix int64, pow *big.Int, freq map[byte]int64) string { powr := big.NewInt(radix) enc := big.NewInt(0).Set(num) enc.Mul(enc, powr.Exp(powr, pow, nil)) base := int64(0) for _, v := range freq { base += v } cf := cumulative_freq(freq) dict := make(map[int64]byte) for k, v := range cf { dict[v] = k } lchar := -1 for i := int64(0); i < base; i++ { if v, ok := dict[i]; ok { lchar = int(v) } else if lchar != -1 { dict[i] = byte(lchar) } } decoded := make([]byte, base) bigBase := big.NewInt(base) for i := base - 1; i >= 0; i-- { pow := big.NewInt(0) pow.Exp(bigBase, big.NewInt(i), nil) div := big.NewInt(0) div.Div(enc, pow) c := dict[div.Int64()] fv := freq[c] cv := cf[c] prod := big.NewInt(0).Mul(pow, big.NewInt(cv)) diff := big.NewInt(0).Sub(enc, prod) enc.Div(diff, big.NewInt(fv)) decoded[base-i-1] = c } return string(decoded) } func main() { var radix = int64(10) strSlice := []string{ `DABDDB`, `DABDDBBDDBA`, `ABRACADABRA`, `TOBEORNOTTOBEORTOBEORNOT`, } for _, str := range strSlice { enc, pow, freq := arithmethic_coding(str, radix) dec := arithmethic_decoding(enc, radix, pow, freq) fmt.Printf("%-25s=> %19s * %d^%s\n", str, enc, radix, pow) if str != dec { panic("\tHowever that is incorrect!") } } }
Transform the following Java implementation into Go, maintaining the same output and logic.
import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.concurrent.atomic.AtomicInteger; import java.util.function.BiConsumer; import java.util.function.IntConsumer; import java.util.stream.Collectors; public class Kosaraju { static class Recursive<I> { I func; } private static List<Integer> kosaraju(List<List<Integer>> g) { int size = g.size(); boolean[] vis = new boolean[size]; int[] l = new int[size]; AtomicInteger x = new AtomicInteger(size); List<List<Integer>> t = new ArrayList<>(); for (int i = 0; i < size; ++i) { t.add(new ArrayList<>()); } Recursive<IntConsumer> visit = new Recursive<>(); visit.func = (int u) -> { if (!vis[u]) { vis[u] = true; for (Integer v : g.get(u)) { visit.func.accept(v); t.get(v).add(u); } int xval = x.decrementAndGet(); l[xval] = u; } }; for (int i = 0; i < size; ++i) { visit.func.accept(i); } int[] c = new int[size]; Recursive<BiConsumer<Integer, Integer>> assign = new Recursive<>(); assign.func = (Integer u, Integer root) -> { if (vis[u]) { vis[u] = false; c[u] = root; for (Integer v : t.get(u)) { assign.func.accept(v, root); } } }; for (int u : l) { assign.func.accept(u, u); } return Arrays.stream(c).boxed().collect(Collectors.toList()); } public static void main(String[] args) { List<List<Integer>> g = new ArrayList<>(); for (int i = 0; i < 8; ++i) { g.add(new ArrayList<>()); } g.get(0).add(1); g.get(1).add(2); g.get(2).add(0); g.get(3).add(1); g.get(3).add(2); g.get(3).add(4); g.get(4).add(3); g.get(4).add(5); g.get(5).add(2); g.get(5).add(6); g.get(6).add(5); g.get(7).add(4); g.get(7).add(6); g.get(7).add(7); List<Integer> output = kosaraju(g); System.out.println(output); } }
package main import "fmt" var g = [][]int{ 0: {1}, 1: {2}, 2: {0}, 3: {1, 2, 4}, 4: {3, 5}, 5: {2, 6}, 6: {5}, 7: {4, 6, 7}, } func main() { fmt.Println(kosaraju(g)) } func kosaraju(g [][]int) []int { vis := make([]bool, len(g)) L := make([]int, len(g)) x := len(L) t := make([][]int, len(g)) var Visit func(int) Visit = func(u int) { if !vis[u] { vis[u] = true for _, v := range g[u] { Visit(v) t[v] = append(t[v], u) } x-- L[x] = u } } for u := range g { Visit(u) } c := make([]int, len(g)) var Assign func(int, int) Assign = func(u, root int) { if vis[u] { vis[u] = false c[u] = root for _, v := range t[u] { Assign(v, root) } } } for _, u := range L { Assign(u, u) } return c }
Produce a functionally identical Go code for the snippet given in Java.
import java.lang.reflect.Method; public class ListMethods { public int examplePublicInstanceMethod(char c, double d) { return 42; } private boolean examplePrivateInstanceMethod(String s) { return true; } public static void main(String[] args) { Class clazz = ListMethods.class; System.out.println("All public methods (including inherited):"); for (Method m : clazz.getMethods()) { System.out.println(m); } System.out.println(); System.out.println("All declared methods (excluding inherited):"); for (Method m : clazz.getDeclaredMethods()) { System.out.println(m); } } }
package main import ( "fmt" "image" "reflect" ) type t int func (r t) Twice() t { return r * 2 } func (r t) Half() t { return r / 2 } func (r t) Less(r2 t) bool { return r < r2 } func (r t) privateMethod() {} func main() { report(t(0)) report(image.Point{}) } func report(x interface{}) { v := reflect.ValueOf(x) t := reflect.TypeOf(x) n := t.NumMethod() fmt.Printf("Type %v has %d exported methods:\n", t, n) const format = "%-6s %-46s %s\n" fmt.Printf(format, "Name", "Method expression", "Method value") for i := 0; i < n; i++ { fmt.Printf(format, t.Method(i).Name, t.Method(i).Func.Type(), v.Method(i).Type(), ) } fmt.Println() }
Generate a Go translation of this Java snippet without changing its computational steps.
import java.lang.reflect.Method; class Example { public int foo(int x) { return 42 + x; } } public class Main { public static void main(String[] args) throws Exception { Object example = new Example(); String name = "foo"; Class<?> clazz = example.getClass(); Method meth = clazz.getMethod(name, int.class); Object result = meth.invoke(example, 5); System.out.println(result); } }
package main import ( "fmt" "reflect" ) type example struct{} func (example) Foo() int { return 42 } func main() { var e example m := reflect.ValueOf(e).MethodByName("Foo") r := m.Call(nil) fmt.Println(r[0].Int()) }
Generate a Go translation of this Java snippet without changing its computational steps.
import java.util.Arrays; import java.util.Objects; import java.util.Random; import java.util.function.Function; public class App { static class Parameters { double omega; double phip; double phig; Parameters(double omega, double phip, double phig) { this.omega = omega; this.phip = phip; this.phig = phig; } } static class State { int iter; double[] gbpos; double gbval; double[] min; double[] max; Parameters parameters; double[][] pos; double[][] vel; double[][] bpos; double[] bval; int nParticles; int nDims; State(int iter, double[] gbpos, double gbval, double[] min, double[] max, Parameters parameters, double[][] pos, double[][] vel, double[][] bpos, double[] bval, int nParticles, int nDims) { this.iter = iter; this.gbpos = gbpos; this.gbval = gbval; this.min = min; this.max = max; this.parameters = parameters; this.pos = pos; this.vel = vel; this.bpos = bpos; this.bval = bval; this.nParticles = nParticles; this.nDims = nDims; } void report(String testfunc) { System.out.printf("Test Function  : %s\n", testfunc); System.out.printf("Iterations  : %d\n", iter); System.out.printf("Global Best Position : %s\n", Arrays.toString(gbpos)); System.out.printf("Global Best value  : %.15f\n", gbval); } } private static State psoInit(double[] min, double[] max, Parameters parameters, int nParticles) { int nDims = min.length; double[][] pos = new double[nParticles][]; for (int i = 0; i < nParticles; ++i) { pos[i] = min.clone(); } double[][] vel = new double[nParticles][nDims]; double[][] bpos = new double[nParticles][]; for (int i = 0; i < nParticles; ++i) { bpos[i] = min.clone(); } double[] bval = new double[nParticles]; for (int i = 0; i < bval.length; ++i) { bval[i] = Double.POSITIVE_INFINITY; } int iter = 0; double[] gbpos = new double[nDims]; for (int i = 0; i < gbpos.length; ++i) { gbpos[i] = Double.POSITIVE_INFINITY; } double gbval = Double.POSITIVE_INFINITY; return new State(iter, gbpos, gbval, min, max, parameters, pos, vel, bpos, bval, nParticles, nDims); } private static Random r = new Random(); private static State pso(Function<double[], Double> fn, State y) { Parameters p = y.parameters; double[] v = new double[y.nParticles]; double[][] bpos = new double[y.nParticles][]; for (int i = 0; i < y.nParticles; ++i) { bpos[i] = y.min.clone(); } double[] bval = new double[y.nParticles]; double[] gbpos = new double[y.nDims]; double gbval = Double.POSITIVE_INFINITY; for (int j = 0; j < y.nParticles; ++j) { v[j] = fn.apply(y.pos[j]); if (v[j] < y.bval[j]) { bpos[j] = y.pos[j]; bval[j] = v[j]; } else { bpos[j] = y.bpos[j]; bval[j] = y.bval[j]; } if (bval[j] < gbval) { gbval = bval[j]; gbpos = bpos[j]; } } double rg = r.nextDouble(); double[][] pos = new double[y.nParticles][y.nDims]; double[][] vel = new double[y.nParticles][y.nDims]; for (int j = 0; j < y.nParticles; ++j) { double rp = r.nextDouble(); boolean ok = true; Arrays.fill(vel[j], 0.0); Arrays.fill(pos[j], 0.0); for (int k = 0; k < y.nDims; ++k) { vel[j][k] = p.omega * y.vel[j][k] + p.phip * rp * (bpos[j][k] - y.pos[j][k]) + p.phig * rg * (gbpos[k] - y.pos[j][k]); pos[j][k] = y.pos[j][k] + vel[j][k]; ok = ok && y.min[k] < pos[j][k] && y.max[k] > pos[j][k]; } if (!ok) { for (int k = 0; k < y.nDims; ++k) { pos[j][k] = y.min[k] + (y.max[k] - y.min[k]) * r.nextDouble(); } } } int iter = 1 + y.iter; return new State( iter, gbpos, gbval, y.min, y.max, y.parameters, pos, vel, bpos, bval, y.nParticles, y.nDims ); } private static State iterate(Function<double[], Double> fn, int n, State y) { State r = y; if (n == Integer.MAX_VALUE) { State old = y; while (true) { r = pso(fn, r); if (Objects.equals(r, old)) break; old = r; } } else { for (int i = 0; i < n; ++i) { r = pso(fn, r); } } return r; } private static double mccormick(double[] x) { double a = x[0]; double b = x[1]; return Math.sin(a + b) + (a - b) * (a - b) + 1.0 + 2.5 * b - 1.5 * a; } private static double michalewicz(double[] x) { int m = 10; int d = x.length; double sum = 0.0; for (int i = 1; i < d; ++i) { double j = x[i - 1]; double k = Math.sin(i * j * j / Math.PI); sum += Math.sin(j) * Math.pow(k, 2.0 * m); } return -sum; } public static void main(String[] args) { State state = psoInit( new double[]{-1.5, -3.0}, new double[]{4.0, 4.0}, new Parameters(0.0, 0.6, 0.3), 100 ); state = iterate(App::mccormick, 40, state); state.report("McCormick"); System.out.printf("f(-.54719, -1.54719) : %.15f\n", mccormick(new double[]{-.54719, -1.54719})); System.out.println(); state = psoInit( new double[]{0.0, 0.0}, new double[]{Math.PI, Math.PI}, new Parameters(0.3, 3.0, 0.3), 1000 ); state = iterate(App::michalewicz, 30, state); state.report("Michalewicz (2D)"); System.out.printf("f(2.20, 1.57)  : %.15f\n", michalewicz(new double[]{2.20, 1.57})); } }
package main import ( "fmt" "math" "math/rand" "time" ) type ff = func([]float64) float64 type parameters struct{ omega, phip, phig float64 } type state struct { iter int gbpos []float64 gbval float64 min []float64 max []float64 params parameters pos [][]float64 vel [][]float64 bpos [][]float64 bval []float64 nParticles int nDims int } func (s state) report(testfunc string) { fmt.Println("Test Function  :", testfunc) fmt.Println("Iterations  :", s.iter) fmt.Println("Global Best Position :", s.gbpos) fmt.Println("Global Best Value  :", s.gbval) } func psoInit(min, max []float64, params parameters, nParticles int) *state { nDims := len(min) pos := make([][]float64, nParticles) vel := make([][]float64, nParticles) bpos := make([][]float64, nParticles) bval := make([]float64, nParticles) for i := 0; i < nParticles; i++ { pos[i] = min vel[i] = make([]float64, nDims) bpos[i] = min bval[i] = math.Inf(1) } iter := 0 gbpos := make([]float64, nDims) for i := 0; i < nDims; i++ { gbpos[i] = math.Inf(1) } gbval := math.Inf(1) return &state{iter, gbpos, gbval, min, max, params, pos, vel, bpos, bval, nParticles, nDims} } func pso(fn ff, y *state) *state { p := y.params v := make([]float64, y.nParticles) bpos := make([][]float64, y.nParticles) bval := make([]float64, y.nParticles) gbpos := make([]float64, y.nDims) gbval := math.Inf(1) for j := 0; j < y.nParticles; j++ { v[j] = fn(y.pos[j]) if v[j] < y.bval[j] { bpos[j] = y.pos[j] bval[j] = v[j] } else { bpos[j] = y.bpos[j] bval[j] = y.bval[j] } if bval[j] < gbval { gbval = bval[j] gbpos = bpos[j] } } rg := rand.Float64() pos := make([][]float64, y.nParticles) vel := make([][]float64, y.nParticles) for j := 0; j < y.nParticles; j++ { pos[j] = make([]float64, y.nDims) vel[j] = make([]float64, y.nDims) rp := rand.Float64() ok := true for z := 0; z < y.nDims; z++ { pos[j][z] = 0 vel[j][z] = 0 } for k := 0; k < y.nDims; k++ { vel[j][k] = p.omega*y.vel[j][k] + p.phip*rp*(bpos[j][k]-y.pos[j][k]) + p.phig*rg*(gbpos[k]-y.pos[j][k]) pos[j][k] = y.pos[j][k] + vel[j][k] ok = ok && y.min[k] < pos[j][k] && y.max[k] > pos[j][k] } if !ok { for k := 0; k < y.nDims; k++ { pos[j][k] = y.min[k] + (y.max[k]-y.min[k])*rand.Float64() } } } iter := 1 + y.iter return &state{iter, gbpos, gbval, y.min, y.max, y.params, pos, vel, bpos, bval, y.nParticles, y.nDims} } func iterate(fn ff, n int, y *state) *state { r := y for i := 0; i < n; i++ { r = pso(fn, r) } return r } func mccormick(x []float64) float64 { a, b := x[0], x[1] return math.Sin(a+b) + (a-b)*(a-b) + 1.0 + 2.5*b - 1.5*a } func michalewicz(x []float64) float64 { m := 10.0 sum := 0.0 for i := 1; i <= len(x); i++ { j := x[i-1] k := math.Sin(float64(i) * j * j / math.Pi) sum += math.Sin(j) * math.Pow(k, 2*m) } return -sum } func main() { rand.Seed(time.Now().UnixNano()) st := psoInit( []float64{-1.5, -3.0}, []float64{4.0, 4.0}, parameters{0.0, 0.6, 0.3}, 100, ) st = iterate(mccormick, 40, st) st.report("McCormick") fmt.Println("f(-.54719, -1.54719) :", mccormick([]float64{-.54719, -1.54719})) fmt.Println() st = psoInit( []float64{0.0, 0.0}, []float64{math.Pi, math.Pi}, parameters{0.3, 0.3, 0.3}, 1000, ) st = iterate(michalewicz, 30, st) st.report("Michalewicz (2D)") fmt.Println("f(2.20, 1.57)  :", michalewicz([]float64{2.2, 1.57}))
Preserve the algorithm and functionality while converting the code from Java to Go.
public static void main(String[] args) { System.out.println(concat("Rosetta", "Code", ":")); } public static String concat(String a, String b, String c) { return a + c + c + b; } Rosetta::Code
package main import "fmt" func f(s1, s2, sep string) string { return s1 + sep + sep + s2 } func main() { fmt.Println(f("Rosetta", "Code", ":")) }
Rewrite the snippet below in Go so it works the same as the original Java code.
import java.math.BigInteger; import static java.util.Arrays.stream; import java.util.*; import static java.util.stream.Collectors.*; public class Test3 { static BigInteger rank(int[] x) { String s = stream(x).mapToObj(String::valueOf).collect(joining("F")); return new BigInteger(s, 16); } static List<BigInteger> unrank(BigInteger n) { BigInteger sixteen = BigInteger.valueOf(16); String s = ""; while (!n.equals(BigInteger.ZERO)) { s = "0123456789ABCDEF".charAt(n.mod(sixteen).intValue()) + s; n = n.divide(sixteen); } return stream(s.split("F")).map(x -> new BigInteger(x)).collect(toList()); } public static void main(String[] args) { int[] s = {1, 2, 3, 10, 100, 987654321}; System.out.println(Arrays.toString(s)); System.out.println(rank(s)); System.out.println(unrank(rank(s))); } }
package main import ( "fmt" "math/big" ) func rank(l []uint) (r big.Int) { for _, n := range l { r.Lsh(&r, n+1) r.SetBit(&r, int(n), 1) } return } func unrank(n big.Int) (l []uint) { m := new(big.Int).Set(&n) for a := m.BitLen(); a > 0; { m.SetBit(m, a-1, 0) b := m.BitLen() l = append(l, uint(a-b-1)) a = b } return } func main() { var b big.Int for i := 0; i <= 10; i++ { b.SetInt64(int64(i)) u := unrank(b) r := rank(u) fmt.Println(i, u, &r) } b.SetString("12345678901234567890", 10) u := unrank(b) r := rank(u) fmt.Printf("\n%v\n%d\n%d\n", &b, u, &r) }
Maintain the same structure and functionality when rewriting this code in Go.
import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.nio.file.*; public class Backup { public static void saveWithBackup(String filename, String... data) throws IOException { Path file = Paths.get(filename).toRealPath(); File backFile = new File(filename + ".backup"); if(!backFile.exists()) { backFile.createNewFile(); } Path back = Paths.get(filename + ".backup").toRealPath(); Files.move(file, back, StandardCopyOption.REPLACE_EXISTING); try(PrintWriter out = new PrintWriter(file.toFile())){ for(int i = 0; i < data.length; i++) { out.print(data[i]); if(i < data.length - 1) { out.println(); } } } } public static void main(String[] args) { try { saveWithBackup("original.txt", "fourth", "fifth", "sixth"); } catch (IOException e) { System.err.println(e); } } }
package main import ( "fmt" "io/ioutil" "os" ) func main() { fn := "myth" bx := ".backup" var err error if tf, err := os.Readlink(fn); err == nil { fn = tf } var fi os.FileInfo if fi, err = os.Stat(fn); err != nil { fmt.Println(err) return } if err = os.Rename(fn, fn+bx); err != nil { fmt.Println(err) return } err = ioutil.WriteFile(fn, []byte("you too!\n"), fi.Mode().Perm()) if err != nil { fmt.Println(err) } }
Maintain the same structure and functionality when rewriting this code in Go.
import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.nio.file.*; public class Backup { public static void saveWithBackup(String filename, String... data) throws IOException { Path file = Paths.get(filename).toRealPath(); File backFile = new File(filename + ".backup"); if(!backFile.exists()) { backFile.createNewFile(); } Path back = Paths.get(filename + ".backup").toRealPath(); Files.move(file, back, StandardCopyOption.REPLACE_EXISTING); try(PrintWriter out = new PrintWriter(file.toFile())){ for(int i = 0; i < data.length; i++) { out.print(data[i]); if(i < data.length - 1) { out.println(); } } } } public static void main(String[] args) { try { saveWithBackup("original.txt", "fourth", "fifth", "sixth"); } catch (IOException e) { System.err.println(e); } } }
package main import ( "fmt" "io/ioutil" "os" ) func main() { fn := "myth" bx := ".backup" var err error if tf, err := os.Readlink(fn); err == nil { fn = tf } var fi os.FileInfo if fi, err = os.Stat(fn); err != nil { fmt.Println(err) return } if err = os.Rename(fn, fn+bx); err != nil { fmt.Println(err) return } err = ioutil.WriteFile(fn, []byte("you too!\n"), fi.Mode().Perm()) if err != nil { fmt.Println(err) } }
Port the following code from Java to Go with equivalent syntax and logic.
import java.math.BigDecimal; public class GeneralisedFloatingPointAddition { public static void main(String[] args) { BigDecimal oneExp72 = new BigDecimal("1E72"); for ( int i = 0 ; i <= 21+7 ; i++ ) { String s = "12345679"; for ( int j = 0 ; j < i ; j++ ) { s += "012345679"; } int exp = 63 - 9*i; s += "E" + exp; BigDecimal num = new BigDecimal(s).multiply(BigDecimal.valueOf(81)).add(new BigDecimal("1E" + exp)); System.out.printf("Test value (%s) equals computed value: %b. Computed = %s%n", oneExp72, num.compareTo(oneExp72) == 0 , num); } } }
package main import ( "fmt" "math/big" ) func repeatedAdd(bf *big.Float, times int) *big.Float { if times < 2 { return bf } var sum big.Float for i := 0; i < times; i++ { sum.Add(&sum, bf) } return &sum } func main() { s := "12345679" t := "123456790" e := 63 var bf, extra big.Float for n := -7; n <= 21; n++ { bf.SetString(fmt.Sprintf("%se%d", s, e)) extra.SetString(fmt.Sprintf("1e%d", e)) bf = *repeatedAdd(&bf, 81) bf.Add(&bf, &extra) fmt.Printf("%2d : %s\n", n, bf.String()) s = t + s e -= 9 } }
Change the programming language of this snippet from Java to Go without modifying what it does.
import java.math.BigDecimal; public class GeneralisedFloatingPointAddition { public static void main(String[] args) { BigDecimal oneExp72 = new BigDecimal("1E72"); for ( int i = 0 ; i <= 21+7 ; i++ ) { String s = "12345679"; for ( int j = 0 ; j < i ; j++ ) { s += "012345679"; } int exp = 63 - 9*i; s += "E" + exp; BigDecimal num = new BigDecimal(s).multiply(BigDecimal.valueOf(81)).add(new BigDecimal("1E" + exp)); System.out.printf("Test value (%s) equals computed value: %b. Computed = %s%n", oneExp72, num.compareTo(oneExp72) == 0 , num); } } }
package main import ( "fmt" "math/big" ) func repeatedAdd(bf *big.Float, times int) *big.Float { if times < 2 { return bf } var sum big.Float for i := 0; i < times; i++ { sum.Add(&sum, bf) } return &sum } func main() { s := "12345679" t := "123456790" e := 63 var bf, extra big.Float for n := -7; n <= 21; n++ { bf.SetString(fmt.Sprintf("%se%d", s, e)) extra.SetString(fmt.Sprintf("1e%d", e)) bf = *repeatedAdd(&bf, 81) bf.Add(&bf, &extra) fmt.Printf("%2d : %s\n", n, bf.String()) s = t + s e -= 9 } }
Write a version of this Java function in Go with identical behavior.
public class ReallyLameTranslationOfJ { public static void main(String[] args) { String s = "She was a soul stripper. She took my heart!"; System.out.println(cheapTrick(s)); System.out.println(cheapTrick(cheapTrick(s))); } static String cheapTrick(String s) { if (s.contains("She")) return s.replaceAll("She", "He"); else if(s.contains("He")) return s.replaceAll("He", "She"); return s; } }
package main import ( "fmt" "strings" ) func reverseGender(s string) string { if strings.Contains(s, "She") { return strings.Replace(s, "She", "He", -1) } else if strings.Contains(s, "He") { return strings.Replace(s, "He", "She", -1) } return s } func main() { s := "She was a soul stripper. She took my heart!" t := reverseGender(s) fmt.Println(t) fmt.Println(reverseGender(t)) }
Change the programming language of this snippet from Java to Go without modifying what it does.
public class ReallyLameTranslationOfJ { public static void main(String[] args) { String s = "She was a soul stripper. She took my heart!"; System.out.println(cheapTrick(s)); System.out.println(cheapTrick(cheapTrick(s))); } static String cheapTrick(String s) { if (s.contains("She")) return s.replaceAll("She", "He"); else if(s.contains("He")) return s.replaceAll("He", "She"); return s; } }
package main import ( "fmt" "strings" ) func reverseGender(s string) string { if strings.Contains(s, "She") { return strings.Replace(s, "She", "He", -1) } else if strings.Contains(s, "He") { return strings.Replace(s, "He", "She", -1) } return s } func main() { s := "She was a soul stripper. She took my heart!" t := reverseGender(s) fmt.Println(t) fmt.Println(reverseGender(t)) }
Rewrite the snippet below in Go so it works the same as the original Java code.
import com.sun.javafx.application.PlatformImpl; import java.io.File; import java.util.Scanner; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicBoolean; import javafx.scene.media.Media; import javafx.scene.media.MediaPlayer; public class AudioAlarm { public static void main(String[] args) throws InterruptedException { Scanner input = new Scanner(System.in); System.out.print("Enter a number of seconds: "); int seconds = Integer.parseInt(input.nextLine()); System.out.print("Enter a filename (must end with .mp3 or .wav): "); String audio = input.nextLine(); TimeUnit.SECONDS.sleep(seconds); Media media = new Media(new File(audio).toURI().toString()); AtomicBoolean stop = new AtomicBoolean(); Runnable onEnd = () -> stop.set(true); PlatformImpl.startup(() -> {}); MediaPlayer player = new MediaPlayer(media); player.setOnEndOfMedia(onEnd); player.setOnError(onEnd); player.setOnHalted(onEnd); player.play(); while (!stop.get()) { Thread.sleep(100); } System.exit(0); } }
package main import ( "bufio" "fmt" "log" "os" "os/exec" "strconv" "time" ) func main() { scanner := bufio.NewScanner(os.Stdin) number := 0 for number < 1 { fmt.Print("Enter number of seconds delay > 0 : ") scanner.Scan() input := scanner.Text() if err := scanner.Err(); err != nil { log.Fatal(err) } number, _ = strconv.Atoi(input) } filename := "" for filename == "" { fmt.Print("Enter name of .mp3 file to play (without extension) : ") scanner.Scan() filename = scanner.Text() if err := scanner.Err(); err != nil { log.Fatal(err) } } cls := "\033[2J\033[0;0H" fmt.Printf("%sAlarm will sound in %d seconds...", cls, number) time.Sleep(time.Duration(number) * time.Second) fmt.Printf(cls) cmd := exec.Command("play", filename+".mp3") if err := cmd.Run(); err != nil { log.Fatal(err) } }
Port the provided Java code into Go while preserving the original functionality.
import java.math.BigDecimal; import java.math.MathContext; import java.math.RoundingMode; public class DecimalToBinary { public static void main(String[] args) { for ( String s : new String[] {"23.34375", ".1", "3.1415926535897932"} ) { String binary = decimalToBinary(new BigDecimal(s)); System.out.printf("%s => %s%n", s, binary); System.out.printf("%s => %s%n", binary, binaryToDecimal(binary)); } } private static BigDecimal binaryToDecimal(String binary) { return binaryToDecimal(binary, 50); } private static BigDecimal binaryToDecimal(String binary, int digits) { int decimalPosition = binary.indexOf("."); String integer = decimalPosition >= 0 ? binary.substring(0, decimalPosition) : binary; String fractional = decimalPosition >= 0 ? binary.substring(decimalPosition+1) : ""; BigDecimal result = BigDecimal.ZERO; BigDecimal powTwo = BigDecimal.ONE; BigDecimal two = BigDecimal.valueOf(2); for ( char c : new StringBuilder(integer).reverse().toString().toCharArray() ) { result = result.add(powTwo.multiply(BigDecimal.valueOf(c - '0'))); powTwo = powTwo.multiply(two); } MathContext mc = new MathContext(digits); powTwo = BigDecimal.ONE; for ( char c : fractional.toCharArray() ) { powTwo = powTwo.divide(two); result = result.add(powTwo.multiply(BigDecimal.valueOf(c - '0')), mc); } return result; } private static String decimalToBinary(BigDecimal decimal) { return decimalToBinary(decimal, 50); } private static String decimalToBinary(BigDecimal decimal, int digits) { BigDecimal integer = decimal.setScale(0, RoundingMode.FLOOR); BigDecimal fractional = decimal.subtract(integer); StringBuilder sb = new StringBuilder(); BigDecimal two = BigDecimal.valueOf(2); BigDecimal zero = BigDecimal.ZERO; while ( integer.compareTo(zero) > 0 ) { BigDecimal[] result = integer.divideAndRemainder(two); sb.append(result[1]); integer = result[0]; } sb.reverse(); int count = 0; if ( fractional.compareTo(zero) != 0 ) { sb.append("."); } while ( fractional.compareTo(zero) != 0 ) { count++; fractional = fractional.multiply(two); sb.append(fractional.setScale(0, RoundingMode.FLOOR)); if ( fractional.compareTo(BigDecimal.ONE) >= 0 ) { fractional = fractional.subtract(BigDecimal.ONE); } if ( count >= digits ) { break; } } return sb.toString(); } }
package main import ( "fmt" "math" "strconv" "strings" ) func decToBin(d float64) string { whole := int64(math.Floor(d)) binary := strconv.FormatInt(whole, 2) + "." dd := d - float64(whole) for dd > 0.0 { r := dd * 2.0 if r >= 1.0 { binary += "1" dd = r - 1.0 } else { binary += "0" dd = r } } return binary } func binToDec(s string) float64 { ss := strings.Replace(s, ".", "", 1) num, _ := strconv.ParseInt(ss, 2, 64) ss = strings.Split(s, ".")[1] ss = strings.Replace(ss, "1", "0", -1) den, _ := strconv.ParseInt("1" + ss, 2, 64) return float64(num) / float64(den) } func main() { f := 23.34375 fmt.Printf("%v\t => %s\n", f, decToBin(f)) s := "1011.11101" fmt.Printf("%s\t => %v\n", s, binToDec(s)) }
Please provide an equivalent version of this Java code in Go.
import java.math.BigDecimal; import java.math.MathContext; import java.math.RoundingMode; public class DecimalToBinary { public static void main(String[] args) { for ( String s : new String[] {"23.34375", ".1", "3.1415926535897932"} ) { String binary = decimalToBinary(new BigDecimal(s)); System.out.printf("%s => %s%n", s, binary); System.out.printf("%s => %s%n", binary, binaryToDecimal(binary)); } } private static BigDecimal binaryToDecimal(String binary) { return binaryToDecimal(binary, 50); } private static BigDecimal binaryToDecimal(String binary, int digits) { int decimalPosition = binary.indexOf("."); String integer = decimalPosition >= 0 ? binary.substring(0, decimalPosition) : binary; String fractional = decimalPosition >= 0 ? binary.substring(decimalPosition+1) : ""; BigDecimal result = BigDecimal.ZERO; BigDecimal powTwo = BigDecimal.ONE; BigDecimal two = BigDecimal.valueOf(2); for ( char c : new StringBuilder(integer).reverse().toString().toCharArray() ) { result = result.add(powTwo.multiply(BigDecimal.valueOf(c - '0'))); powTwo = powTwo.multiply(two); } MathContext mc = new MathContext(digits); powTwo = BigDecimal.ONE; for ( char c : fractional.toCharArray() ) { powTwo = powTwo.divide(two); result = result.add(powTwo.multiply(BigDecimal.valueOf(c - '0')), mc); } return result; } private static String decimalToBinary(BigDecimal decimal) { return decimalToBinary(decimal, 50); } private static String decimalToBinary(BigDecimal decimal, int digits) { BigDecimal integer = decimal.setScale(0, RoundingMode.FLOOR); BigDecimal fractional = decimal.subtract(integer); StringBuilder sb = new StringBuilder(); BigDecimal two = BigDecimal.valueOf(2); BigDecimal zero = BigDecimal.ZERO; while ( integer.compareTo(zero) > 0 ) { BigDecimal[] result = integer.divideAndRemainder(two); sb.append(result[1]); integer = result[0]; } sb.reverse(); int count = 0; if ( fractional.compareTo(zero) != 0 ) { sb.append("."); } while ( fractional.compareTo(zero) != 0 ) { count++; fractional = fractional.multiply(two); sb.append(fractional.setScale(0, RoundingMode.FLOOR)); if ( fractional.compareTo(BigDecimal.ONE) >= 0 ) { fractional = fractional.subtract(BigDecimal.ONE); } if ( count >= digits ) { break; } } return sb.toString(); } }
package main import ( "fmt" "math" "strconv" "strings" ) func decToBin(d float64) string { whole := int64(math.Floor(d)) binary := strconv.FormatInt(whole, 2) + "." dd := d - float64(whole) for dd > 0.0 { r := dd * 2.0 if r >= 1.0 { binary += "1" dd = r - 1.0 } else { binary += "0" dd = r } } return binary } func binToDec(s string) float64 { ss := strings.Replace(s, ".", "", 1) num, _ := strconv.ParseInt(ss, 2, 64) ss = strings.Split(s, ".")[1] ss = strings.Replace(ss, "1", "0", -1) den, _ := strconv.ParseInt("1" + ss, 2, 64) return float64(num) / float64(den) } func main() { f := 23.34375 fmt.Printf("%v\t => %s\n", f, decToBin(f)) s := "1011.11101" fmt.Printf("%s\t => %v\n", s, binToDec(s)) }
Change the following Java code into Go without altering its purpose.
import java.io.File; import java.lang.reflect.Method; import java.net.URI; import java.util.Arrays; import javax.tools.JavaCompiler; import javax.tools.SimpleJavaFileObject; import javax.tools.ToolProvider; public class Eval { private static final String CLASS_NAME = "TempPleaseDeleteMe"; private static class StringCompiler extends SimpleJavaFileObject { final String m_sourceCode; private StringCompiler( final String sourceCode ) { super( URI.create( "string: m_sourceCode = sourceCode; } @Override public CharSequence getCharContent( final boolean ignoreEncodingErrors ) { return m_sourceCode; } private boolean compile() { final JavaCompiler javac = ToolProvider.getSystemJavaCompiler(); return javac.getTask( null, javac.getStandardFileManager( null, null, null ), null, null, null, Arrays.asList( this ) ).call(); } private double callEval( final double x ) throws Exception { final Class<?> clarse = Class.forName( CLASS_NAME ); final Method eval = clarse.getMethod( "eval", double.class ); return ( Double ) eval.invoke( null, x ); } } public static double evalWithX( final String code, final double x ) throws Exception { final StringCompiler sc = new StringCompiler( "class " + CLASS_NAME + "{public static double eval(double x){return (" + code + ");}}" ); if ( ! sc.compile() ) throw new RuntimeException( "Compiler error" ); return sc.callEval( x ); } public static void main( final String [] args ) throws Exception { final String expression = args [ 0 ]; final double x1 = Double.parseDouble( args [ 1 ] ); final double x2 = Double.parseDouble( args [ 2 ] ); System.out.println( evalWithX( expression, x1 ) - evalWithX( expression, x2 ) ); } }
package main import ( "bitbucket.org/binet/go-eval/pkg/eval" "fmt" "go/parser" "go/token" ) func main() { squareExpr := "x*x" fset := token.NewFileSet() squareAst, err := parser.ParseExpr(squareExpr) if err != nil { fmt.Println(err) return } w := eval.NewWorld() wVar := new(intV) err = w.DefineVar("x", eval.IntType, wVar) if err != nil { fmt.Println(err) return } squareCode, err := w.CompileExpr(fset, squareAst) if err != nil { fmt.Println(err) return } *wVar = 5 r0, err := squareCode.Run() if err != nil { fmt.Println(err) return } *wVar-- r1, err := squareCode.Run() if err != nil { fmt.Println(err) return } fmt.Println(r0.(eval.IntValue).Get(nil) - r1.(eval.IntValue).Get(nil)) } type intV int64 func (v *intV) String() string { return fmt.Sprint(*v) } func (v *intV) Get(*eval.Thread) int64 { return int64(*v) } func (v *intV) Set(_ *eval.Thread, x int64) { *v = intV(x) } func (v *intV) Assign(t *eval.Thread, o eval.Value) { *v = intV(o.(eval.IntValue).Get(t)) }
Generate an equivalent Go version of this Java code.
import java.io.File; import java.lang.reflect.Method; import java.net.URI; import java.util.Arrays; import javax.tools.JavaCompiler; import javax.tools.SimpleJavaFileObject; import javax.tools.ToolProvider; public class Eval { private static final String CLASS_NAME = "TempPleaseDeleteMe"; private static class StringCompiler extends SimpleJavaFileObject { final String m_sourceCode; private StringCompiler( final String sourceCode ) { super( URI.create( "string: m_sourceCode = sourceCode; } @Override public CharSequence getCharContent( final boolean ignoreEncodingErrors ) { return m_sourceCode; } private boolean compile() { final JavaCompiler javac = ToolProvider.getSystemJavaCompiler(); return javac.getTask( null, javac.getStandardFileManager( null, null, null ), null, null, null, Arrays.asList( this ) ).call(); } private double callEval( final double x ) throws Exception { final Class<?> clarse = Class.forName( CLASS_NAME ); final Method eval = clarse.getMethod( "eval", double.class ); return ( Double ) eval.invoke( null, x ); } } public static double evalWithX( final String code, final double x ) throws Exception { final StringCompiler sc = new StringCompiler( "class " + CLASS_NAME + "{public static double eval(double x){return (" + code + ");}}" ); if ( ! sc.compile() ) throw new RuntimeException( "Compiler error" ); return sc.callEval( x ); } public static void main( final String [] args ) throws Exception { final String expression = args [ 0 ]; final double x1 = Double.parseDouble( args [ 1 ] ); final double x2 = Double.parseDouble( args [ 2 ] ); System.out.println( evalWithX( expression, x1 ) - evalWithX( expression, x2 ) ); } }
package main import ( "bitbucket.org/binet/go-eval/pkg/eval" "fmt" "go/parser" "go/token" ) func main() { squareExpr := "x*x" fset := token.NewFileSet() squareAst, err := parser.ParseExpr(squareExpr) if err != nil { fmt.Println(err) return } w := eval.NewWorld() wVar := new(intV) err = w.DefineVar("x", eval.IntType, wVar) if err != nil { fmt.Println(err) return } squareCode, err := w.CompileExpr(fset, squareAst) if err != nil { fmt.Println(err) return } *wVar = 5 r0, err := squareCode.Run() if err != nil { fmt.Println(err) return } *wVar-- r1, err := squareCode.Run() if err != nil { fmt.Println(err) return } fmt.Println(r0.(eval.IntValue).Get(nil) - r1.(eval.IntValue).Get(nil)) } type intV int64 func (v *intV) String() string { return fmt.Sprint(*v) } func (v *intV) Get(*eval.Thread) int64 { return int64(*v) } func (v *intV) Set(_ *eval.Thread, x int64) { *v = intV(x) } func (v *intV) Assign(t *eval.Thread, o eval.Value) { *v = intV(o.(eval.IntValue).Get(t)) }
Write the same code in Go as shown below in Java.
import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.math.BigInteger; import java.util.ArrayList; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; public class CheckMachinFormula { private static String FILE_NAME = "MachinFormula.txt"; public static void main(String[] args) { try { runPrivate(); } catch (Exception e) { e.printStackTrace(); } } private static void runPrivate() throws IOException { try (BufferedReader reader = new BufferedReader(new FileReader(new File(FILE_NAME)));) { String inLine = null; while ( (inLine = reader.readLine()) != null ) { String[] split = inLine.split("="); System.out.println(tanLeft(split[0].trim()) + " = " + split[1].trim().replaceAll("\\s+", " ") + " = " + tanRight(split[1].trim())); } } } private static String tanLeft(String formula) { if ( formula.compareTo("pi/4") == 0 ) { return "1"; } throw new RuntimeException("ERROR 104: Unknown left side: " + formula); } private static final Pattern ARCTAN_PATTERN = Pattern.compile("(-{0,1}\\d+)\\*arctan\\((\\d+)/(\\d+)\\)"); private static Fraction tanRight(String formula) { Matcher matcher = ARCTAN_PATTERN.matcher(formula); List<Term> terms = new ArrayList<>(); while ( matcher.find() ) { terms.add(new Term(Integer.parseInt(matcher.group(1)), new Fraction(matcher.group(2), matcher.group(3)))); } return evaluateArctan(terms); } private static Fraction evaluateArctan(List<Term> terms) { if ( terms.size() == 1 ) { Term term = terms.get(0); return evaluateArctan(term.coefficient, term.fraction); } int size = terms.size(); List<Term> left = terms.subList(0, (size+1) / 2); List<Term> right = terms.subList((size+1) / 2, size); return arctanFormula(evaluateArctan(left), evaluateArctan(right)); } private static Fraction evaluateArctan(int coefficient, Fraction fraction) { if ( coefficient == 1 ) { return fraction; } else if ( coefficient < 0 ) { return evaluateArctan(-coefficient, fraction).negate(); } if ( coefficient % 2 == 0 ) { Fraction f = evaluateArctan(coefficient/2, fraction); return arctanFormula(f, f); } Fraction a = evaluateArctan(coefficient/2, fraction); Fraction b = evaluateArctan(coefficient - (coefficient/2), fraction); return arctanFormula(a, b); } private static Fraction arctanFormula(Fraction f1, Fraction f2) { return f1.add(f2).divide(Fraction.ONE.subtract(f1.multiply(f2))); } private static class Fraction { public static final Fraction ONE = new Fraction("1", "1"); private BigInteger numerator; private BigInteger denominator; public Fraction(String num, String den) { numerator = new BigInteger(num); denominator = new BigInteger(den); } public Fraction(BigInteger num, BigInteger den) { numerator = num; denominator = den; } public Fraction negate() { return new Fraction(numerator.negate(), denominator); } public Fraction add(Fraction f) { BigInteger gcd = denominator.gcd(f.denominator); BigInteger first = numerator.multiply(f.denominator.divide(gcd)); BigInteger second = f.numerator.multiply(denominator.divide(gcd)); return new Fraction(first.add(second), denominator.multiply(f.denominator).divide(gcd)); } public Fraction subtract(Fraction f) { return add(f.negate()); } public Fraction multiply(Fraction f) { BigInteger num = numerator.multiply(f.numerator); BigInteger den = denominator.multiply(f.denominator); BigInteger gcd = num.gcd(den); return new Fraction(num.divide(gcd), den.divide(gcd)); } public Fraction divide(Fraction f) { return multiply(new Fraction(f.denominator, f.numerator)); } @Override public String toString() { if ( denominator.compareTo(BigInteger.ONE) == 0 ) { return numerator.toString(); } return numerator + " / " + denominator; } } private static class Term { private int coefficient; private Fraction fraction; public Term(int c, Fraction f) { coefficient = c; fraction = f; } } }
package main import ( "fmt" "math/big" ) type mTerm struct { a, n, d int64 } var testCases = [][]mTerm{ {{1, 1, 2}, {1, 1, 3}}, {{2, 1, 3}, {1, 1, 7}}, {{4, 1, 5}, {-1, 1, 239}}, {{5, 1, 7}, {2, 3, 79}}, {{1, 1, 2}, {1, 1, 5}, {1, 1, 8}}, {{4, 1, 5}, {-1, 1, 70}, {1, 1, 99}}, {{5, 1, 7}, {4, 1, 53}, {2, 1, 4443}}, {{6, 1, 8}, {2, 1, 57}, {1, 1, 239}}, {{8, 1, 10}, {-1, 1, 239}, {-4, 1, 515}}, {{12, 1, 18}, {8, 1, 57}, {-5, 1, 239}}, {{16, 1, 21}, {3, 1, 239}, {4, 3, 1042}}, {{22, 1, 28}, {2, 1, 443}, {-5, 1, 1393}, {-10, 1, 11018}}, {{22, 1, 38}, {17, 7, 601}, {10, 7, 8149}}, {{44, 1, 57}, {7, 1, 239}, {-12, 1, 682}, {24, 1, 12943}}, {{88, 1, 172}, {51, 1, 239}, {32, 1, 682}, {44, 1, 5357}, {68, 1, 12943}}, {{88, 1, 172}, {51, 1, 239}, {32, 1, 682}, {44, 1, 5357}, {68, 1, 12944}}, } func main() { for _, m := range testCases { fmt.Printf("tan %v = %v\n", m, tans(m)) } } var one = big.NewRat(1, 1) func tans(m []mTerm) *big.Rat { if len(m) == 1 { return tanEval(m[0].a, big.NewRat(m[0].n, m[0].d)) } half := len(m) / 2 a := tans(m[:half]) b := tans(m[half:]) r := new(big.Rat) return r.Quo(new(big.Rat).Add(a, b), r.Sub(one, r.Mul(a, b))) } func tanEval(coef int64, f *big.Rat) *big.Rat { if coef == 1 { return f } if coef < 0 { r := tanEval(-coef, f) return r.Neg(r) } ca := coef / 2 cb := coef - ca a := tanEval(ca, f) b := tanEval(cb, f) r := new(big.Rat) return r.Quo(new(big.Rat).Add(a, b), r.Sub(one, r.Mul(a, b))) }
Write the same code in Go as shown below in Java.
import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.math.BigInteger; import java.util.ArrayList; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; public class CheckMachinFormula { private static String FILE_NAME = "MachinFormula.txt"; public static void main(String[] args) { try { runPrivate(); } catch (Exception e) { e.printStackTrace(); } } private static void runPrivate() throws IOException { try (BufferedReader reader = new BufferedReader(new FileReader(new File(FILE_NAME)));) { String inLine = null; while ( (inLine = reader.readLine()) != null ) { String[] split = inLine.split("="); System.out.println(tanLeft(split[0].trim()) + " = " + split[1].trim().replaceAll("\\s+", " ") + " = " + tanRight(split[1].trim())); } } } private static String tanLeft(String formula) { if ( formula.compareTo("pi/4") == 0 ) { return "1"; } throw new RuntimeException("ERROR 104: Unknown left side: " + formula); } private static final Pattern ARCTAN_PATTERN = Pattern.compile("(-{0,1}\\d+)\\*arctan\\((\\d+)/(\\d+)\\)"); private static Fraction tanRight(String formula) { Matcher matcher = ARCTAN_PATTERN.matcher(formula); List<Term> terms = new ArrayList<>(); while ( matcher.find() ) { terms.add(new Term(Integer.parseInt(matcher.group(1)), new Fraction(matcher.group(2), matcher.group(3)))); } return evaluateArctan(terms); } private static Fraction evaluateArctan(List<Term> terms) { if ( terms.size() == 1 ) { Term term = terms.get(0); return evaluateArctan(term.coefficient, term.fraction); } int size = terms.size(); List<Term> left = terms.subList(0, (size+1) / 2); List<Term> right = terms.subList((size+1) / 2, size); return arctanFormula(evaluateArctan(left), evaluateArctan(right)); } private static Fraction evaluateArctan(int coefficient, Fraction fraction) { if ( coefficient == 1 ) { return fraction; } else if ( coefficient < 0 ) { return evaluateArctan(-coefficient, fraction).negate(); } if ( coefficient % 2 == 0 ) { Fraction f = evaluateArctan(coefficient/2, fraction); return arctanFormula(f, f); } Fraction a = evaluateArctan(coefficient/2, fraction); Fraction b = evaluateArctan(coefficient - (coefficient/2), fraction); return arctanFormula(a, b); } private static Fraction arctanFormula(Fraction f1, Fraction f2) { return f1.add(f2).divide(Fraction.ONE.subtract(f1.multiply(f2))); } private static class Fraction { public static final Fraction ONE = new Fraction("1", "1"); private BigInteger numerator; private BigInteger denominator; public Fraction(String num, String den) { numerator = new BigInteger(num); denominator = new BigInteger(den); } public Fraction(BigInteger num, BigInteger den) { numerator = num; denominator = den; } public Fraction negate() { return new Fraction(numerator.negate(), denominator); } public Fraction add(Fraction f) { BigInteger gcd = denominator.gcd(f.denominator); BigInteger first = numerator.multiply(f.denominator.divide(gcd)); BigInteger second = f.numerator.multiply(denominator.divide(gcd)); return new Fraction(first.add(second), denominator.multiply(f.denominator).divide(gcd)); } public Fraction subtract(Fraction f) { return add(f.negate()); } public Fraction multiply(Fraction f) { BigInteger num = numerator.multiply(f.numerator); BigInteger den = denominator.multiply(f.denominator); BigInteger gcd = num.gcd(den); return new Fraction(num.divide(gcd), den.divide(gcd)); } public Fraction divide(Fraction f) { return multiply(new Fraction(f.denominator, f.numerator)); } @Override public String toString() { if ( denominator.compareTo(BigInteger.ONE) == 0 ) { return numerator.toString(); } return numerator + " / " + denominator; } } private static class Term { private int coefficient; private Fraction fraction; public Term(int c, Fraction f) { coefficient = c; fraction = f; } } }
package main import ( "fmt" "math/big" ) type mTerm struct { a, n, d int64 } var testCases = [][]mTerm{ {{1, 1, 2}, {1, 1, 3}}, {{2, 1, 3}, {1, 1, 7}}, {{4, 1, 5}, {-1, 1, 239}}, {{5, 1, 7}, {2, 3, 79}}, {{1, 1, 2}, {1, 1, 5}, {1, 1, 8}}, {{4, 1, 5}, {-1, 1, 70}, {1, 1, 99}}, {{5, 1, 7}, {4, 1, 53}, {2, 1, 4443}}, {{6, 1, 8}, {2, 1, 57}, {1, 1, 239}}, {{8, 1, 10}, {-1, 1, 239}, {-4, 1, 515}}, {{12, 1, 18}, {8, 1, 57}, {-5, 1, 239}}, {{16, 1, 21}, {3, 1, 239}, {4, 3, 1042}}, {{22, 1, 28}, {2, 1, 443}, {-5, 1, 1393}, {-10, 1, 11018}}, {{22, 1, 38}, {17, 7, 601}, {10, 7, 8149}}, {{44, 1, 57}, {7, 1, 239}, {-12, 1, 682}, {24, 1, 12943}}, {{88, 1, 172}, {51, 1, 239}, {32, 1, 682}, {44, 1, 5357}, {68, 1, 12943}}, {{88, 1, 172}, {51, 1, 239}, {32, 1, 682}, {44, 1, 5357}, {68, 1, 12944}}, } func main() { for _, m := range testCases { fmt.Printf("tan %v = %v\n", m, tans(m)) } } var one = big.NewRat(1, 1) func tans(m []mTerm) *big.Rat { if len(m) == 1 { return tanEval(m[0].a, big.NewRat(m[0].n, m[0].d)) } half := len(m) / 2 a := tans(m[:half]) b := tans(m[half:]) r := new(big.Rat) return r.Quo(new(big.Rat).Add(a, b), r.Sub(one, r.Mul(a, b))) } func tanEval(coef int64, f *big.Rat) *big.Rat { if coef == 1 { return f } if coef < 0 { r := tanEval(-coef, f) return r.Neg(r) } ca := coef / 2 cb := coef - ca a := tanEval(ca, f) b := tanEval(cb, f) r := new(big.Rat) return r.Quo(new(big.Rat).Add(a, b), r.Sub(one, r.Mul(a, b))) }
Ensure the translated Go code behaves exactly like the original Java snippet.
class MD5 { private static final int INIT_A = 0x67452301; private static final int INIT_B = (int)0xEFCDAB89L; private static final int INIT_C = (int)0x98BADCFEL; private static final int INIT_D = 0x10325476; private static final int[] SHIFT_AMTS = { 7, 12, 17, 22, 5, 9, 14, 20, 4, 11, 16, 23, 6, 10, 15, 21 }; private static final int[] TABLE_T = new int[64]; static { for (int i = 0; i < 64; i++) TABLE_T[i] = (int)(long)((1L << 32) * Math.abs(Math.sin(i + 1))); } public static byte[] computeMD5(byte[] message) { int messageLenBytes = message.length; int numBlocks = ((messageLenBytes + 8) >>> 6) + 1; int totalLen = numBlocks << 6; byte[] paddingBytes = new byte[totalLen - messageLenBytes]; paddingBytes[0] = (byte)0x80; long messageLenBits = (long)messageLenBytes << 3; for (int i = 0; i < 8; i++) { paddingBytes[paddingBytes.length - 8 + i] = (byte)messageLenBits; messageLenBits >>>= 8; } int a = INIT_A; int b = INIT_B; int c = INIT_C; int d = INIT_D; int[] buffer = new int[16]; for (int i = 0; i < numBlocks; i ++) { int index = i << 6; for (int j = 0; j < 64; j++, index++) buffer[j >>> 2] = ((int)((index < messageLenBytes) ? message[index] : paddingBytes[index - messageLenBytes]) << 24) | (buffer[j >>> 2] >>> 8); int originalA = a; int originalB = b; int originalC = c; int originalD = d; for (int j = 0; j < 64; j++) { int div16 = j >>> 4; int f = 0; int bufferIndex = j; switch (div16) { case 0: f = (b & c) | (~b & d); break; case 1: f = (b & d) | (c & ~d); bufferIndex = (bufferIndex * 5 + 1) & 0x0F; break; case 2: f = b ^ c ^ d; bufferIndex = (bufferIndex * 3 + 5) & 0x0F; break; case 3: f = c ^ (b | ~d); bufferIndex = (bufferIndex * 7) & 0x0F; break; } int temp = b + Integer.rotateLeft(a + f + buffer[bufferIndex] + TABLE_T[j], SHIFT_AMTS[(div16 << 2) | (j & 3)]); a = d; d = c; c = b; b = temp; } a += originalA; b += originalB; c += originalC; d += originalD; } byte[] md5 = new byte[16]; int count = 0; for (int i = 0; i < 4; i++) { int n = (i == 0) ? a : ((i == 1) ? b : ((i == 2) ? c : d)); for (int j = 0; j < 4; j++) { md5[count++] = (byte)n; n >>>= 8; } } return md5; } public static String toHexString(byte[] b) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < b.length; i++) { sb.append(String.format("%02X", b[i] & 0xFF)); } return sb.toString(); } public static void main(String[] args) { String[] testStrings = { "", "a", "abc", "message digest", "abcdefghijklmnopqrstuvwxyz", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", "12345678901234567890123456789012345678901234567890123456789012345678901234567890" }; for (String s : testStrings) System.out.println("0x" + toHexString(computeMD5(s.getBytes())) + " <== \"" + s + "\""); return; } }
package main import ( "fmt" "math" "bytes" "encoding/binary" ) type testCase struct { hashCode string string } var testCases = []testCase{ {"d41d8cd98f00b204e9800998ecf8427e", ""}, {"0cc175b9c0f1b6a831c399e269772661", "a"}, {"900150983cd24fb0d6963f7d28e17f72", "abc"}, {"f96b697d7cb7938d525a2f31aaf161d0", "message digest"}, {"c3fcd3d76192e4007dfb496cca67e13b", "abcdefghijklmnopqrstuvwxyz"}, {"d174ab98d277d9f5a5611c2c9f419d9f", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"}, {"57edf4a22be3c955ac49da2e2107b67a", "12345678901234567890" + "123456789012345678901234567890123456789012345678901234567890"}, } func main() { for _, tc := range testCases { fmt.Printf("%s\n%x\n\n", tc.hashCode, md5(tc.string)) } } var shift = [...]uint{7, 12, 17, 22, 5, 9, 14, 20, 4, 11, 16, 23, 6, 10, 15, 21} var table [64]uint32 func init() { for i := range table { table[i] = uint32((1 << 32) * math.Abs(math.Sin(float64(i + 1)))) } } func md5(s string) (r [16]byte) { padded := bytes.NewBuffer([]byte(s)) padded.WriteByte(0x80) for padded.Len() % 64 != 56 { padded.WriteByte(0) } messageLenBits := uint64(len(s)) * 8 binary.Write(padded, binary.LittleEndian, messageLenBits) var a, b, c, d uint32 = 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476 var buffer [16]uint32 for binary.Read(padded, binary.LittleEndian, buffer[:]) == nil { a1, b1, c1, d1 := a, b, c, d for j := 0; j < 64; j++ { var f uint32 bufferIndex := j round := j >> 4 switch round { case 0: f = (b1 & c1) | (^b1 & d1) case 1: f = (b1 & d1) | (c1 & ^d1) bufferIndex = (bufferIndex*5 + 1) & 0x0F case 2: f = b1 ^ c1 ^ d1 bufferIndex = (bufferIndex*3 + 5) & 0x0F case 3: f = c1 ^ (b1 | ^d1) bufferIndex = (bufferIndex * 7) & 0x0F } sa := shift[(round<<2)|(j&3)] a1 += f + buffer[bufferIndex] + table[j] a1, d1, c1, b1 = d1, c1, b1, a1<<sa|a1>>(32-sa)+b1 } a, b, c, d = a+a1, b+b1, c+c1, d+d1 } binary.Write(bytes.NewBuffer(r[:0]), binary.LittleEndian, []uint32{a, b, c, d}) return }
Change the programming language of this snippet from Java to Go without modifying what it does.
import java.util.Random; public class KMeansWithKpp{ public Point[] points; public Point[] centroids; Random rand; public int n; public int k; private KMeansWithKpp(){ } KMeansWithKpp(Point[] p, int clusters){ points = p; n = p.length; k = Math.max(1, clusters); centroids = new Point[k]; rand = new Random(); } private static double distance(Point a, Point b){ return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y); } private static int nearest(Point pt, Point[] others, int len){ double minD = Double.MAX_VALUE; int index = pt.group; len = Math.min(others.length, len); double dist; for (int i = 0; i < len; i++) { if (minD > (dist = distance(pt, others[i]))) { minD = dist; index = i; } } return index; } private static double nearestDistance(Point pt, Point[] others, int len){ double minD = Double.MAX_VALUE; len = Math.min(others.length, len); double dist; for (int i = 0; i < len; i++) { if (minD > (dist = distance(pt, others[i]))) { minD = dist; } } return minD; } private void kpp(){ centroids[0] = points[rand.nextInt(n)]; double[] dist = new double[n]; double sum = 0; for (int i = 1; i < k; i++) { for (int j = 0; j < n; j++) { dist[j] = nearestDistance(points[j], centroids, i); sum += dist[j]; } sum = (sum * rand.nextInt(Integer.MAX_VALUE)) / Integer.MAX_VALUE; for (int j = 0; j < n; j++) { if ((sum -= dist[j]) > 0) continue; centroids[i].x = points[j].x; centroids[i].y = points[j].y; } } for (int i = 0; i < n; i++) { points[i].group = nearest(points[i], centroids, k); } } public void kMeans(int maxTimes){ if (k == 1 || n <= 0) { return; } if(k >= n){ for(int i =0; i < n; i++){ points[i].group = i; } return; } maxTimes = Math.max(1, maxTimes); int changed; int bestPercent = n/1000; int minIndex; kpp(); do { for (Point c : centroids) { c.x = 0.0; c.y = 0.0; c.group = 0; } for (Point pt : points) { if(pt.group < 0 || pt.group > centroids.length){ pt.group = rand.nextInt(centroids.length); } centroids[pt.group].x += pt.x; centroids[pt.group].y = pt.y; centroids[pt.group].group++; } for (Point c : centroids) { c.x /= c.group; c.y /= c.group; } changed = 0; for (Point pt : points) { minIndex = nearest(pt, centroids, k); if (k != pt.group) { changed++; pt.group = minIndex; } } maxTimes--; } while (changed > bestPercent && maxTimes > 0); } } class Point{ public double x; public double y; public int group; Point(){ x = y = 0.0; group = 0; } public Point[] getRandomPlaneData(double minX, double maxX, double minY, double maxY, int size){ if (size <= 0) return null; double xdiff, ydiff; xdiff = maxX - minX; ydiff = maxY - minY; if (minX > maxX) { xdiff = minX - maxX; minX = maxX; } if (maxY < minY) { ydiff = minY - maxY; minY = maxY; } Point[] data = new Point[size]; Random rand = new Random(); for (int i = 0; i < size; i++) { data[i].x = minX + (xdiff * rand.nextInt(Integer.MAX_VALUE)) / Integer.MAX_VALUE; data[i].y = minY + (ydiff * rand.nextInt(Integer.MAX_VALUE)) / Integer.MAX_VALUE; } return data; } public Point[] getRandomPolarData(double radius, int size){ if (size <= 0) { return null; } Point[] data = new Point[size]; double radi, arg; Random rand = new Random(); for (int i = 0; i < size; i++) { radi = (radius * rand.nextInt(Integer.MAX_VALUE)) / Integer.MAX_VALUE; arg = (2 * Math.PI * rand.nextInt(Integer.MAX_VALUE)) / Integer.MAX_VALUE; data[i].x = radi * Math.cos(arg); data[i].y = radi * Math.sin(arg); } return data; } }
package main import ( "fmt" "image" "image/color" "image/draw" "image/png" "math" "math/rand" "os" "time" ) type r2 struct { x, y float64 } type r2c struct { r2 c int } func kmpp(k int, data []r2c) { kMeans(data, kmppSeeds(k, data)) } func kmppSeeds(k int, data []r2c) []r2 { s := make([]r2, k) s[0] = data[rand.Intn(len(data))].r2 d2 := make([]float64, len(data)) for i := 1; i < k; i++ { var sum float64 for j, p := range data { _, dMin := nearest(p, s[:i]) d2[j] = dMin * dMin sum += d2[j] } target := rand.Float64() * sum j := 0 for sum = d2[0]; sum < target; sum += d2[j] { j++ } s[i] = data[j].r2 } return s } func nearest(p r2c, mean []r2) (int, float64) { iMin := 0 dMin := math.Hypot(p.x-mean[0].x, p.y-mean[0].y) for i := 1; i < len(mean); i++ { d := math.Hypot(p.x-mean[i].x, p.y-mean[i].y) if d < dMin { dMin = d iMin = i } } return iMin, dMin } func kMeans(data []r2c, mean []r2) { for i, p := range data { cMin, _ := nearest(p, mean) data[i].c = cMin } mLen := make([]int, len(mean)) for { for i := range mean { mean[i] = r2{} mLen[i] = 0 } for _, p := range data { mean[p.c].x += p.x mean[p.c].y += p.y mLen[p.c]++ } for i := range mean { inv := 1 / float64(mLen[i]) mean[i].x *= inv mean[i].y *= inv } var changes int for i, p := range data { if cMin, _ := nearest(p, mean); cMin != p.c { changes++ data[i].c = cMin } } if changes == 0 { return } } } type ecParam struct { k int nPoints int xBox, yBox int stdv int } func main() { ec := &ecParam{6, 30000, 300, 200, 30} origin, data := genECData(ec) vis(ec, data, "origin") fmt.Println("Data set origins:") fmt.Println(" x y") for _, o := range origin { fmt.Printf("%5.1f %5.1f\n", o.x, o.y) } kmpp(ec.k, data) fmt.Println( "\nCluster centroids, mean distance from centroid, number of points:") fmt.Println(" x y distance points") cent := make([]r2, ec.k) cLen := make([]int, ec.k) inv := make([]float64, ec.k) for _, p := range data { cent[p.c].x += p.x cent[p.c].y += p.y cLen[p.c]++ } for i, iLen := range cLen { inv[i] = 1 / float64(iLen) cent[i].x *= inv[i] cent[i].y *= inv[i] } dist := make([]float64, ec.k) for _, p := range data { dist[p.c] += math.Hypot(p.x-cent[p.c].x, p.y-cent[p.c].y) } for i, iLen := range cLen { fmt.Printf("%5.1f %5.1f %8.1f %6d\n", cent[i].x, cent[i].y, dist[i]*inv[i], iLen) } vis(ec, data, "clusters") } func genECData(ec *ecParam) (orig []r2, data []r2c) { rand.Seed(time.Now().UnixNano()) orig = make([]r2, ec.k) data = make([]r2c, ec.nPoints) for i, n := 0, 0; i < ec.k; i++ { x := rand.Float64() * float64(ec.xBox) y := rand.Float64() * float64(ec.yBox) orig[i] = r2{x, y} for j := ec.nPoints / ec.k; j > 0; j-- { data[n].x = rand.NormFloat64()*float64(ec.stdv) + x data[n].y = rand.NormFloat64()*float64(ec.stdv) + y data[n].c = i n++ } } return } func vis(ec *ecParam, data []r2c, fn string) { colors := make([]color.NRGBA, ec.k) for i := range colors { i3 := i * 3 third := i3 / ec.k frac := uint8((i3 % ec.k) * 255 / ec.k) switch third { case 0: colors[i] = color.NRGBA{frac, 255 - frac, 0, 255} case 1: colors[i] = color.NRGBA{0, frac, 255 - frac, 255} case 2: colors[i] = color.NRGBA{255 - frac, 0, frac, 255} } } bounds := image.Rect(-ec.stdv, -ec.stdv, ec.xBox+ec.stdv, ec.yBox+ec.stdv) im := image.NewNRGBA(bounds) draw.Draw(im, bounds, image.NewUniform(color.White), image.ZP, draw.Src) fMinX := float64(bounds.Min.X) fMaxX := float64(bounds.Max.X) fMinY := float64(bounds.Min.Y) fMaxY := float64(bounds.Max.Y) for _, p := range data { imx := math.Floor(p.x) imy := math.Floor(float64(ec.yBox) - p.y) if imx >= fMinX && imx < fMaxX && imy >= fMinY && imy < fMaxY { im.SetNRGBA(int(imx), int(imy), colors[p.c]) } } f, err := os.Create(fn + ".png") if err != nil { fmt.Println(err) return } err = png.Encode(f, im) if err != nil { fmt.Println(err) } err = f.Close() if err != nil { fmt.Println(err) } }
Change the following Java code into Go without altering its purpose.
import java.io.*; import java.util.*; public class MazeSolver { private static String[] readLines (InputStream f) throws IOException { BufferedReader r = new BufferedReader (new InputStreamReader (f, "US-ASCII")); ArrayList<String> lines = new ArrayList<String>(); String line; while ((line = r.readLine()) != null) lines.add (line); return lines.toArray(new String[0]); } private static char[][] decimateHorizontally (String[] lines) { final int width = (lines[0].length() + 1) / 2; char[][] c = new char[lines.length][width]; for (int i = 0 ; i < lines.length ; i++) for (int j = 0 ; j < width ; j++) c[i][j] = lines[i].charAt (j * 2); return c; } private static boolean solveMazeRecursively (char[][] maze, int x, int y, int d) { boolean ok = false; for (int i = 0 ; i < 4 && !ok ; i++) if (i != d) switch (i) { case 0: if (maze[y-1][x] == ' ') ok = solveMazeRecursively (maze, x, y - 2, 2); break; case 1: if (maze[y][x+1] == ' ') ok = solveMazeRecursively (maze, x + 2, y, 3); break; case 2: if (maze[y+1][x] == ' ') ok = solveMazeRecursively (maze, x, y + 2, 0); break; case 3: if (maze[y][x-1] == ' ') ok = solveMazeRecursively (maze, x - 2, y, 1); break; } if (x == 1 && y == 1) ok = true; if (ok) { maze[y][x] = '*'; switch (d) { case 0: maze[y-1][x] = '*'; break; case 1: maze[y][x+1] = '*'; break; case 2: maze[y+1][x] = '*'; break; case 3: maze[y][x-1] = '*'; break; } } return ok; } private static void solveMaze (char[][] maze) { solveMazeRecursively (maze, maze[0].length - 2, maze.length - 2, -1); } private static String[] expandHorizontally (char[][] maze) { char[] tmp = new char[3]; String[] lines = new String[maze.length]; for (int i = 0 ; i < maze.length ; i++) { StringBuilder sb = new StringBuilder(maze[i].length * 2); for (int j = 0 ; j < maze[i].length ; j++) if (j % 2 == 0) sb.append (maze[i][j]); else { tmp[0] = tmp[1] = tmp[2] = maze[i][j]; if (tmp[1] == '*') tmp[0] = tmp[2] = ' '; sb.append (tmp); } lines[i] = sb.toString(); } return lines; } public static void main (String[] args) throws IOException { InputStream f = (args.length > 0 ? new FileInputStream (args[0]) : System.in); String[] lines = readLines (f); char[][] maze = decimateHorizontally (lines); solveMaze (maze); String[] solvedLines = expandHorizontally (maze); for (int i = 0 ; i < solvedLines.length ; i++) System.out.println (solvedLines[i]); } }
package main import ( "bytes" "fmt" "math/rand" "time" ) type maze struct { c2 [][]byte h2 [][]byte v2 [][]byte } func newMaze(rows, cols int) *maze { c := make([]byte, rows*cols) h := bytes.Repeat([]byte{'-'}, rows*cols) v := bytes.Repeat([]byte{'|'}, rows*cols) c2 := make([][]byte, rows) h2 := make([][]byte, rows) v2 := make([][]byte, rows) for i := range h2 { c2[i] = c[i*cols : (i+1)*cols] h2[i] = h[i*cols : (i+1)*cols] v2[i] = v[i*cols : (i+1)*cols] } return &maze{c2, h2, v2} } func (m *maze) String() string { hWall := []byte("+---") hOpen := []byte("+ ") vWall := []byte("| ") vOpen := []byte(" ") rightCorner := []byte("+\n") rightWall := []byte("|\n") var b []byte for r, hw := range m.h2 { for _, h := range hw { if h == '-' || r == 0 { b = append(b, hWall...) } else { b = append(b, hOpen...) if h != '-' && h != 0 { b[len(b)-2] = h } } } b = append(b, rightCorner...) for c, vw := range m.v2[r] { if vw == '|' || c == 0 { b = append(b, vWall...) } else { b = append(b, vOpen...) if vw != '|' && vw != 0 { b[len(b)-4] = vw } } if m.c2[r][c] != 0 { b[len(b)-2] = m.c2[r][c] } } b = append(b, rightWall...) } for _ = range m.h2[0] { b = append(b, hWall...) } b = append(b, rightCorner...) return string(b) } func (m *maze) gen() { m.g2(rand.Intn(len(m.c2)), rand.Intn(len(m.c2[0]))) } const ( up = iota dn rt lf ) func (m *maze) g2(r, c int) { m.c2[r][c] = ' ' for _, dir := range rand.Perm(4) { switch dir { case up: if r > 0 && m.c2[r-1][c] == 0 { m.h2[r][c] = 0 m.g2(r-1, c) } case lf: if c > 0 && m.c2[r][c-1] == 0 { m.v2[r][c] = 0 m.g2(r, c-1) } case dn: if r < len(m.c2)-1 && m.c2[r+1][c] == 0 { m.h2[r+1][c] = 0 m.g2(r+1, c) } case rt: if c < len(m.c2[0])-1 && m.c2[r][c+1] == 0 { m.v2[r][c+1] = 0 m.g2(r, c+1) } } } } func main() { rand.Seed(time.Now().UnixNano()) const height = 4 const width = 7 m := newMaze(height, width) m.gen() m.solve( rand.Intn(height), rand.Intn(width), rand.Intn(height), rand.Intn(width)) fmt.Print(m) } func (m *maze) solve(ra, ca, rz, cz int) { var rSolve func(ra, ca, dir int) bool rSolve = func(r, c, dir int) bool { if r == rz && c == cz { m.c2[r][c] = 'F' return true } if dir != dn && m.h2[r][c] == 0 { if rSolve(r-1, c, up) { m.c2[r][c] = '^' m.h2[r][c] = '^' return true } } if dir != up && r+1 < len(m.h2) && m.h2[r+1][c] == 0 { if rSolve(r+1, c, dn) { m.c2[r][c] = 'v' m.h2[r+1][c] = 'v' return true } } if dir != lf && c+1 < len(m.v2[0]) && m.v2[r][c+1] == 0 { if rSolve(r, c+1, rt) { m.c2[r][c] = '>' m.v2[r][c+1] = '>' return true } } if dir != rt && m.v2[r][c] == 0 { if rSolve(r, c-1, lf) { m.c2[r][c] = '<' m.v2[r][c] = '<' return true } } return false } rSolve(ra, ca, -1) m.c2[ra][ca] = 'S' }
Keep all operations the same but rewrite the snippet in Go.
import java.util.*; public class RandomShuffle { public static void main(String[] args) { Random rand = new Random(); List<Integer> list = new ArrayList<>(); for (int j = 1; j <= 20; ++j) list.add(j); Collections.shuffle(list, rand); System.out.println(list); } }
package main import ( "fmt" "log" "math/rand" "time" ) func generate(from, to int64) { if to < from || from < 0 { log.Fatal("Invalid range.") } span := to - from + 1 generated := make([]bool, span) count := span for count > 0 { n := from + rand.Int63n(span) if !generated[n-from] { generated[n-from] = true fmt.Printf("%2d ", n) count-- } } fmt.Println() } func main() { rand.Seed(time.Now().UnixNano()) for i := 1; i <= 5; i++ { generate(1, 20) } }
Write a version of this Java function in Go with identical behavior.
import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Stack; public class IQPuzzle { public static void main(String[] args) { System.out.printf(" "); for ( int start = 1 ; start < Puzzle.MAX_PEGS ; start++ ) { System.out.printf("  %,6d", start); } System.out.printf("%n"); for ( int start = 1 ; start < Puzzle.MAX_PEGS ; start++ ) { System.out.printf("%2d", start); Map<Integer,Integer> solutions = solve(start); for ( int end = 1 ; end < Puzzle.MAX_PEGS ; end++ ) { System.out.printf("  %,6d", solutions.containsKey(end) ? solutions.get(end) : 0); } System.out.printf("%n"); } int moveNum = 0; System.out.printf("%nOne Solution:%n"); for ( Move m : oneSolution ) { moveNum++; System.out.printf("Move %d = %s%n", moveNum, m); } } private static List<Move> oneSolution = null; private static Map<Integer, Integer> solve(int emptyPeg) { Puzzle puzzle = new Puzzle(emptyPeg); Map<Integer,Integer> solutions = new HashMap<>(); Stack<Puzzle> stack = new Stack<Puzzle>(); stack.push(puzzle); while ( ! stack.isEmpty() ) { Puzzle p = stack.pop(); if ( p.solved() ) { solutions.merge(p.getLastPeg(), 1, (v1,v2) -> v1 + v2); if ( oneSolution == null ) { oneSolution = p.moves; } continue; } for ( Move move : p.getValidMoves() ) { Puzzle pMove = p.move(move); stack.add(pMove); } } return solutions; } private static class Puzzle { public static int MAX_PEGS = 16; private boolean[] pegs = new boolean[MAX_PEGS]; private List<Move> moves; public Puzzle(int emptyPeg) { for ( int i = 1 ; i < MAX_PEGS ; i++ ) { pegs[i] = true; } pegs[emptyPeg] = false; moves = new ArrayList<>(); } public Puzzle() { for ( int i = 1 ; i < MAX_PEGS ; i++ ) { pegs[i] = true; } moves = new ArrayList<>(); } private static Map<Integer,List<Move>> validMoves = new HashMap<>(); static { validMoves.put(1, Arrays.asList(new Move(1, 2, 4), new Move(1, 3, 6))); validMoves.put(2, Arrays.asList(new Move(2, 4, 7), new Move(2, 5, 9))); validMoves.put(3, Arrays.asList(new Move(3, 5, 8), new Move(3, 6, 10))); validMoves.put(4, Arrays.asList(new Move(4, 2, 1), new Move(4, 5, 6), new Move(4, 8, 13), new Move(4, 7, 11))); validMoves.put(5, Arrays.asList(new Move(5, 8, 12), new Move(5, 9, 14))); validMoves.put(6, Arrays.asList(new Move(6, 3, 1), new Move(6, 5, 4), new Move(6, 9, 13), new Move(6, 10, 15))); validMoves.put(7, Arrays.asList(new Move(7, 4, 2), new Move(7, 8, 9))); validMoves.put(8, Arrays.asList(new Move(8, 5, 3), new Move(8, 9, 10))); validMoves.put(9, Arrays.asList(new Move(9, 5, 2), new Move(9, 8, 7))); validMoves.put(10, Arrays.asList(new Move(10, 6, 3), new Move(10, 9, 8))); validMoves.put(11, Arrays.asList(new Move(11, 7, 4), new Move(11, 12, 13))); validMoves.put(12, Arrays.asList(new Move(12, 8, 5), new Move(12, 13, 14))); validMoves.put(13, Arrays.asList(new Move(13, 12, 11), new Move(13, 8, 4), new Move(13, 9, 6), new Move(13, 14, 15))); validMoves.put(14, Arrays.asList(new Move(14, 13, 12), new Move(14, 9, 5))); validMoves.put(15, Arrays.asList(new Move(15, 14, 13), new Move(15, 10, 6))); } public List<Move> getValidMoves() { List<Move> moves = new ArrayList<Move>(); for ( int i = 1 ; i < MAX_PEGS ; i++ ) { if ( pegs[i] ) { for ( Move testMove : validMoves.get(i) ) { if ( pegs[testMove.jump] && ! pegs[testMove.end] ) { moves.add(testMove); } } } } return moves; } public boolean solved() { boolean foundFirstPeg = false; for ( int i = 1 ; i < MAX_PEGS ; i++ ) { if ( pegs[i] ) { if ( foundFirstPeg ) { return false; } foundFirstPeg = true; } } return true; } public Puzzle move(Move move) { Puzzle p = new Puzzle(); if ( ! pegs[move.start] || ! pegs[move.jump] || pegs[move.end] ) { throw new RuntimeException("Invalid move."); } for ( int i = 1 ; i < MAX_PEGS ; i++ ) { p.pegs[i] = pegs[i]; } p.pegs[move.start] = false; p.pegs[move.jump] = false; p.pegs[move.end] = true; for ( Move m : moves ) { p.moves.add(new Move(m.start, m.jump, m.end)); } p.moves.add(new Move(move.start, move.jump, move.end)); return p; } public int getLastPeg() { for ( int i = 1 ; i < MAX_PEGS ; i++ ) { if ( pegs[i] ) { return i; } } throw new RuntimeException("ERROR: Illegal position."); } @Override public String toString() { StringBuilder sb = new StringBuilder(); sb.append("["); for ( int i = 1 ; i < MAX_PEGS ; i++ ) { sb.append(pegs[i] ? 1 : 0); sb.append(","); } sb.setLength(sb.length()-1); sb.append("]"); return sb.toString(); } } private static class Move { int start; int jump; int end; public Move(int s, int j, int e) { start = s; jump = j; end = e; } @Override public String toString() { StringBuilder sb = new StringBuilder(); sb.append("{"); sb.append("s=" + start); sb.append(", j=" + jump); sb.append(", e=" + end); sb.append("}"); return sb.toString(); } } }
package main import "fmt" type solution struct{ peg, over, land int } type move struct{ from, to int } var emptyStart = 1 var board [16]bool var jumpMoves = [16][]move{ {}, {{2, 4}, {3, 6}}, {{4, 7}, {5, 9}}, {{5, 8}, {6, 10}}, {{2, 1}, {5, 6}, {7, 11}, {8, 13}}, {{8, 12}, {9, 14}}, {{3, 1}, {5, 4}, {9, 13}, {10, 15}}, {{4, 2}, {8, 9}}, {{5, 3}, {9, 10}}, {{5, 2}, {8, 7}}, {{9, 8}}, {{12, 13}}, {{8, 5}, {13, 14}}, {{8, 4}, {9, 6}, {12, 11}, {14, 15}}, {{9, 5}, {13, 12}}, {{10, 6}, {14, 13}}, } var solutions []solution func initBoard() { for i := 1; i < 16; i++ { board[i] = true } board[emptyStart] = false } func (sol solution) split() (int, int, int) { return sol.peg, sol.over, sol.land } func (mv move) split() (int, int) { return mv.from, mv.to } func drawBoard() { var pegs [16]byte for i := 1; i < 16; i++ { if board[i] { pegs[i] = fmt.Sprintf("%X", i)[0] } else { pegs[i] = '-' } } fmt.Printf(" %c\n", pegs[1]) fmt.Printf(" %c %c\n", pegs[2], pegs[3]) fmt.Printf(" %c %c %c\n", pegs[4], pegs[5], pegs[6]) fmt.Printf(" %c %c %c %c\n", pegs[7], pegs[8], pegs[9], pegs[10]) fmt.Printf(" %c %c %c %c %c\n", pegs[11], pegs[12], pegs[13], pegs[14], pegs[15]) } func solved() bool { count := 0 for _, b := range board { if b { count++ } } return count == 1 } func solve() { if solved() { return } for peg := 1; peg < 16; peg++ { if board[peg] { for _, mv := range jumpMoves[peg] { over, land := mv.split() if board[over] && !board[land] { saveBoard := board board[peg] = false board[over] = false board[land] = true solutions = append(solutions, solution{peg, over, land}) solve() if solved() { return } board = saveBoard solutions = solutions[:len(solutions)-1] } } } } } func main() { initBoard() solve() initBoard() drawBoard() fmt.Printf("Starting with peg %X removed\n\n", emptyStart) for _, solution := range solutions { peg, over, land := solution.split() board[peg] = false board[over] = false board[land] = true drawBoard() fmt.Printf("Peg %X jumped over %X to land on %X\n\n", peg, over, land) } }
Rewrite this program in Go while keeping its functionality equivalent to the Java version.
import javax.imageio.ImageIO; import java.awt.*; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.math.BigInteger; import java.security.SecureRandom; import java.util.Random; import java.util.Scanner; public class csprngBBS { public static Scanner input = new Scanner(System.in); private static final String fileformat = "png"; private static String bitsStri = ""; private static String parityEven = ""; private static String leastSig = ""; private static String randomJavaUtil = ""; private static int width = 0; private static int BIT_LENGTH = 0; private static final Random rand = new SecureRandom(); private static BigInteger p = null; private static BigInteger q = null; private static BigInteger m = null; private static BigInteger seed = null; private static BigInteger seedFinal = null; private static final Random randMathUtil = new SecureRandom(); public static void main(String[] args) throws IOException { System.out.print("Width: "); width = input.nextInt(); System.out.print("Bit-Length: "); BIT_LENGTH = input.nextInt(); System.out.print("Generator format: "); String useGenerator = input.next(); p = BigInteger.probablePrime(BIT_LENGTH, rand); q = BigInteger.probablePrime(BIT_LENGTH, rand); m = p.multiply(q); seed = BigInteger.probablePrime(BIT_LENGTH,rand); seedFinal = seed.add(BigInteger.ZERO); if(useGenerator.contains("parity") && useGenerator.contains("significant")) { findLeastSignificant(); findBitParityEven(); createImage(parityEven, "parityEven"); createImage(leastSig, "significant"); } if(useGenerator.contains("parity") && !useGenerator.contains("significant")){ findBitParityEven(); } if(useGenerator.contains("significant") && !useGenerator.contains("parity")){ findLeastSignificant(); createImage(leastSig, "significant"); } if(useGenerator.contains("util")){ findRandomJava(randMathUtil); createImage(randomJavaUtil, "randomUtilJava"); } } public static void findRandomJava(Random random){ for(int x = 1; x <= Math.pow(width, 2); x++){ randomJavaUtil += random.nextInt(2); } } public static void findBitParityEven(){ for(int x = 1; x <= Math.pow(width, 2); x++) { seed = seed.pow(2).mod(m); bitsStri = convertBinary(seed); char[] bits = bitsStri.toCharArray(); int counter = 0; for (char bit : bits) { if (bit == '1') { counter++; } } if (counter % 2 != 0) { parityEven += "1"; } else { parityEven += "0"; } } } public static void findLeastSignificant(){ seed = seedFinal; for(int x = 1; x <= Math.pow(width, 2); x++){ seed = seed.pow(2).mod(m); leastSig += bitsStri.substring(bitsStri.length() - 1); } } public static String convertBinary(BigInteger value){ StringBuilder total = new StringBuilder(); BigInteger two = BigInteger.TWO; while(value.compareTo(BigInteger.ZERO) > 0){ total.append(value.mod(two)); value = value.divide(two); } return total.reverse().toString(); } public static void createImage(String useThis, String fileName) throws IOException { int length = csprngBBS.width; BufferedImage bufferedImage = new BufferedImage(length, length, 1); Graphics2D g2d = bufferedImage.createGraphics(); for (int y = 1; y <= length; y++) { for (int x = 1; x <= length; x++) { if (useThis.startsWith("1")) { useThis = useThis.substring(1); g2d.setColor(Color.BLACK); g2d.fillRect(x, y, 1, 1); } else if (useThis.startsWith("0")) { useThis = useThis.substring(1); g2d.setColor(Color.WHITE); g2d.fillRect(x, y, 1, 1); } } System.out.print(y + "\t"); } g2d.dispose(); File file = new File("REPLACEFILEPATHHERE" + fileName + "." + fileformat); ImageIO.write(bufferedImage, fileformat, file); } }
package main import ( "image" "image/color" "image/png" "log" "math/rand" "os" "time" ) func main() { rand.Seed(time.Now().UnixNano()) img := image.NewNRGBA(image.Rect(0, 0, 1000, 1000)) for x := 0; x < 1000; x++ { for y := 0; y < 1000; y++ { col := color.RGBA{uint8(rand.Intn(256)), uint8(rand.Intn(256)), uint8(rand.Intn(256)), 255} img.Set(x, y, col) } } fileName := "pseudorandom_number_generator.png" imgFile, err := os.Create(fileName) if err != nil { log.Fatal(err) } defer imgFile.Close() if err := png.Encode(imgFile, img); err != nil { imgFile.Close() log.Fatal(err) } }
Produce a functionally identical Go code for the snippet given in Java.
import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; import java.util.stream.Collectors; import java.util.stream.IntStream; public class Main { private static List<List<Integer>> fourFaceCombos() { List<List<Integer>> res = new ArrayList<>(); Set<Integer> found = new HashSet<>(); for (int i = 1; i <= 4; i++) { for (int j = 1; j <= 4; j++) { for (int k = 1; k <= 4; k++) { for (int l = 1; l <= 4; l++) { List<Integer> c = IntStream.of(i, j, k, l).sorted().boxed().collect(Collectors.toList()); int key = 64 * (c.get(0) - 1) + 16 * (c.get(1) - 1) + 4 * (c.get(2) - 1) + (c.get(3) - 1); if (found.add(key)) { res.add(c); } } } } } return res; } private static int cmp(List<Integer> x, List<Integer> y) { int xw = 0; int yw = 0; for (int i = 0; i < 4; i++) { for (int j = 0; j < 4; j++) { if (x.get(i) > y.get(j)) { xw++; } else if (x.get(i) < y.get(j)) { yw++; } } } return Integer.compare(xw, yw); } private static List<List<List<Integer>>> findIntransitive3(List<List<Integer>> cs) { int c = cs.size(); List<List<List<Integer>>> res = new ArrayList<>(); for (int i = 0; i < c; i++) { for (int j = 0; j < c; j++) { if (cmp(cs.get(i), cs.get(j)) == -1) { for (List<Integer> kl : cs) { if (cmp(cs.get(j), kl) == -1 && cmp(kl, cs.get(i)) == -1) { res.add(List.of(cs.get(i), cs.get(j), kl)); } } } } } return res; } private static List<List<List<Integer>>> findIntransitive4(List<List<Integer>> cs) { int c = cs.size(); List<List<List<Integer>>> res = new ArrayList<>(); for (int i = 0; i < c; i++) { for (int j = 0; j < c; j++) { if (cmp(cs.get(i), cs.get(j)) == -1) { for (int k = 0; k < cs.size(); k++) { if (cmp(cs.get(j), cs.get(k)) == -1) { for (List<Integer> ll : cs) { if (cmp(cs.get(k), ll) == -1 && cmp(ll, cs.get(i)) == -1) { res.add(List.of(cs.get(i), cs.get(j), cs.get(k), ll)); } } } } } } } return res; } public static void main(String[] args) { List<List<Integer>> combos = fourFaceCombos(); System.out.printf("Number of eligible 4-faced dice: %d%n", combos.size()); System.out.println(); List<List<List<Integer>>> it3 = findIntransitive3(combos); System.out.printf("%d ordered lists of 3 non-transitive dice found, namely:%n", it3.size()); for (List<List<Integer>> a : it3) { System.out.println(a); } System.out.println(); List<List<List<Integer>>> it4 = findIntransitive4(combos); System.out.printf("%d ordered lists of 4 non-transitive dice found, namely:%n", it4.size()); for (List<List<Integer>> a : it4) { System.out.println(a); } } }
package main import ( "fmt" "sort" ) func fourFaceCombs() (res [][4]int) { found := make([]bool, 256) for i := 1; i <= 4; i++ { for j := 1; j <= 4; j++ { for k := 1; k <= 4; k++ { for l := 1; l <= 4; l++ { c := [4]int{i, j, k, l} sort.Ints(c[:]) key := 64*(c[0]-1) + 16*(c[1]-1) + 4*(c[2]-1) + (c[3] - 1) if !found[key] { found[key] = true res = append(res, c) } } } } } return } func cmp(x, y [4]int) int { xw := 0 yw := 0 for i := 0; i < 4; i++ { for j := 0; j < 4; j++ { if x[i] > y[j] { xw++ } else if y[j] > x[i] { yw++ } } } if xw < yw { return -1 } else if xw > yw { return 1 } return 0 } func findIntransitive3(cs [][4]int) (res [][3][4]int) { var c = len(cs) for i := 0; i < c; i++ { for j := 0; j < c; j++ { for k := 0; k < c; k++ { first := cmp(cs[i], cs[j]) if first == -1 { second := cmp(cs[j], cs[k]) if second == -1 { third := cmp(cs[i], cs[k]) if third == 1 { res = append(res, [3][4]int{cs[i], cs[j], cs[k]}) } } } } } } return } func findIntransitive4(cs [][4]int) (res [][4][4]int) { c := len(cs) for i := 0; i < c; i++ { for j := 0; j < c; j++ { for k := 0; k < c; k++ { for l := 0; l < c; l++ { first := cmp(cs[i], cs[j]) if first == -1 { second := cmp(cs[j], cs[k]) if second == -1 { third := cmp(cs[k], cs[l]) if third == -1 { fourth := cmp(cs[i], cs[l]) if fourth == 1 { res = append(res, [4][4]int{cs[i], cs[j], cs[k], cs[l]}) } } } } } } } } return } func main() { combs := fourFaceCombs() fmt.Println("Number of eligible 4-faced dice", len(combs)) it3 := findIntransitive3(combs) fmt.Printf("\n%d ordered lists of 3 non-transitive dice found, namely:\n", len(it3)) for _, a := range it3 { fmt.Println(a) } it4 := findIntransitive4(combs) fmt.Printf("\n%d ordered lists of 4 non-transitive dice found, namely:\n", len(it4)) for _, a := range it4 { fmt.Println(a) } }
Can you help me rewrite this code in Go instead of Java, keeping it the same logically?
public class HistoryVariable { private Object value; public HistoryVariable(Object v) { value = v; } public void update(Object v) { value = v; } public Object undo() { return value; } @Override public String toString() { return value.toString(); } public void dispose() { } }
package main import ( "fmt" "sort" "sync" "time" ) type history struct { timestamp tsFunc hs []hset } type tsFunc func() time.Time type hset struct { int t time.Time } func newHistory(ts tsFunc) history { return history{ts, []hset{{t: ts()}}} } func (h history) int() int { return h.hs[len(h.hs)-1].int } func (h *history) set(x int) time.Time { t := h.timestamp() h.hs = append(h.hs, hset{x, t}) return t } func (h history) dump() { for _, hs := range h.hs { fmt.Println(hs.t.Format(time.StampNano), hs.int) } } func (h history) recall(t time.Time) (int, bool) { i := sort.Search(len(h.hs), func(i int) bool { return h.hs[i].t.After(t) }) if i > 0 { return h.hs[i-1].int, true } return 0, false } func newTimestamper() tsFunc { var last time.Time return func() time.Time { if t := time.Now(); t.After(last) { last = t } else { last.Add(1) } return last } } func newProtectedTimestamper() tsFunc { var last time.Time var m sync.Mutex return func() (t time.Time) { t = time.Now() m.Lock() if t.After(last) { last = t } else { last.Add(1) t = last } m.Unlock() return } } func main() { ts := newTimestamper() h := newHistory(ts) ref := []time.Time{h.set(3), h.set(1), h.set(4)} fmt.Println("History of variable h:") h.dump() fmt.Println("Recalling values:") for _, t := range ref { rv, _ := h.recall(t) fmt.Println(rv) } }
Change the following Java code into Go without altering its purpose.
import java.awt.*; import java.awt.event.ActionEvent; import java.util.*; import javax.swing.*; import javax.swing.Timer; public class Perceptron extends JPanel { class Trainer { double[] inputs; int answer; Trainer(double x, double y, int a) { inputs = new double[]{x, y, 1}; answer = a; } } Trainer[] training = new Trainer[2000]; double[] weights; double c = 0.00001; int count; public Perceptron(int n) { Random r = new Random(); Dimension dim = new Dimension(640, 360); setPreferredSize(dim); setBackground(Color.white); weights = new double[n]; for (int i = 0; i < weights.length; i++) { weights[i] = r.nextDouble() * 2 - 1; } for (int i = 0; i < training.length; i++) { double x = r.nextDouble() * dim.width; double y = r.nextDouble() * dim.height; int answer = y < f(x) ? -1 : 1; training[i] = new Trainer(x, y, answer); } new Timer(10, (ActionEvent e) -> { repaint(); }).start(); } private double f(double x) { return x * 0.7 + 40; } int feedForward(double[] inputs) { assert inputs.length == weights.length : "weights and input length mismatch"; double sum = 0; for (int i = 0; i < weights.length; i++) { sum += inputs[i] * weights[i]; } return activate(sum); } int activate(double s) { return s > 0 ? 1 : -1; } void train(double[] inputs, int desired) { int guess = feedForward(inputs); double error = desired - guess; for (int i = 0; i < weights.length; i++) { weights[i] += c * error * inputs[i]; } } @Override public void paintComponent(Graphics gg) { super.paintComponent(gg); Graphics2D g = (Graphics2D) gg; g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); int x = getWidth(); int y = (int) f(x); g.setStroke(new BasicStroke(2)); g.setColor(Color.orange); g.drawLine(0, (int) f(0), x, y); train(training[count].inputs, training[count].answer); count = (count + 1) % training.length; g.setStroke(new BasicStroke(1)); g.setColor(Color.black); for (int i = 0; i < count; i++) { int guess = feedForward(training[i].inputs); x = (int) training[i].inputs[0] - 4; y = (int) training[i].inputs[1] - 4; if (guess > 0) g.drawOval(x, y, 8, 8); else g.fillOval(x, y, 8, 8); } } public static void main(String[] args) { SwingUtilities.invokeLater(() -> { JFrame f = new JFrame(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setTitle("Perceptron"); f.setResizable(false); f.add(new Perceptron(3), BorderLayout.CENTER); f.pack(); f.setLocationRelativeTo(null); f.setVisible(true); }); } }
package main import ( "github.com/fogleman/gg" "math/rand" "time" ) const c = 0.00001 func linear(x float64) float64 { return x*0.7 + 40 } type trainer struct { inputs []float64 answer int } func newTrainer(x, y float64, a int) *trainer { return &trainer{[]float64{x, y, 1}, a} } type perceptron struct { weights []float64 training []*trainer } func newPerceptron(n, w, h int) *perceptron { weights := make([]float64, n) for i := 0; i < n; i++ { weights[i] = rand.Float64()*2 - 1 } training := make([]*trainer, 2000) for i := 0; i < 2000; i++ { x := rand.Float64() * float64(w) y := rand.Float64() * float64(h) answer := 1 if y < linear(x) { answer = -1 } training[i] = newTrainer(x, y, answer) } return &perceptron{weights, training} } func (p *perceptron) feedForward(inputs []float64) int { if len(inputs) != len(p.weights) { panic("weights and input length mismatch, program terminated") } sum := 0.0 for i, w := range p.weights { sum += inputs[i] * w } if sum > 0 { return 1 } return -1 } func (p *perceptron) train(inputs []float64, desired int) { guess := p.feedForward(inputs) err := float64(desired - guess) for i := range p.weights { p.weights[i] += c * err * inputs[i] } } func (p *perceptron) draw(dc *gg.Context, iterations int) { le := len(p.training) for i, count := 0, 0; i < iterations; i, count = i+1, (count+1)%le { p.train(p.training[count].inputs, p.training[count].answer) } x := float64(dc.Width()) y := linear(x) dc.SetLineWidth(2) dc.SetRGB255(0, 0, 0) dc.DrawLine(0, linear(0), x, y) dc.Stroke() dc.SetLineWidth(1) for i := 0; i < le; i++ { guess := p.feedForward(p.training[i].inputs) x := p.training[i].inputs[0] - 4 y := p.training[i].inputs[1] - 4 if guess > 0 { dc.SetRGB(0, 0, 1) } else { dc.SetRGB(1, 0, 0) } dc.DrawCircle(x, y, 8) dc.Stroke() } } func main() { rand.Seed(time.Now().UnixNano()) w, h := 640, 360 perc := newPerceptron(3, w, h) dc := gg.NewContext(w, h) dc.SetRGB(1, 1, 1) dc.Clear() perc.draw(dc, 2000) dc.SavePNG("perceptron.png") }
Convert this Java snippet to Go and keep its semantics consistent.
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStream; import java.lang.reflect.InvocationTargetException; import java.net.URI; import java.util.HashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; import javax.tools.FileObject; import javax.tools.ForwardingJavaFileManager; import javax.tools.JavaCompiler; import javax.tools.JavaFileObject; import javax.tools.SimpleJavaFileObject; import javax.tools.StandardJavaFileManager; import javax.tools.StandardLocation; import javax.tools.ToolProvider; public class Evaluator{ public static void main(String[] args){ new Evaluator().eval( "SayHello", "public class SayHello{public void speak(){System.out.println(\"Hello world\");}}", "speak" ); } void eval(String className, String classCode, String methodName){ Map<String, ByteArrayOutputStream> classCache = new HashMap<>(); JavaCompiler compiler = ToolProvider.getSystemJavaCompiler(); if ( null == compiler ) throw new RuntimeException("Could not get a compiler."); StandardJavaFileManager sfm = compiler.getStandardFileManager(null, null, null); ForwardingJavaFileManager<StandardJavaFileManager> fjfm = new ForwardingJavaFileManager<StandardJavaFileManager>(sfm){ @Override public JavaFileObject getJavaFileForOutput(Location location, String className, JavaFileObject.Kind kind, FileObject sibling) throws IOException{ if (StandardLocation.CLASS_OUTPUT == location && JavaFileObject.Kind.CLASS == kind) return new SimpleJavaFileObject(URI.create("mem: @Override public OutputStream openOutputStream() throws IOException{ ByteArrayOutputStream baos = new ByteArrayOutputStream(); classCache.put(className, baos); return baos; } }; else throw new IllegalArgumentException("Unexpected output file requested: " + location + ", " + className + ", " + kind); } }; List<JavaFileObject> files = new LinkedList<JavaFileObject>(){{ add( new SimpleJavaFileObject(URI.create("string: @Override public CharSequence getCharContent(boolean ignoreEncodingErrors){ return classCode; } } ); }}; compiler.getTask(null, fjfm, null, null, null, files).call(); try{ Class<?> clarse = new ClassLoader(){ @Override public Class<?> findClass(String name){ if (! name.startsWith(className)) throw new IllegalArgumentException("This class loader is for " + className + " - could not handle \"" + name + '"'); byte[] bytes = classCache.get(name).toByteArray(); return defineClass(name, bytes, 0, bytes.length); } }.loadClass(className); clarse.getMethod(methodName).invoke(clarse.newInstance()); }catch(ClassNotFoundException | InstantiationException | IllegalAccessException | NoSuchMethodException | InvocationTargetException x){ throw new RuntimeException("Run failed: " + x, x); } } }
package main import ( "fmt" "bitbucket.org/binet/go-eval/pkg/eval" "go/token" ) func main() { w := eval.NewWorld(); fset := token.NewFileSet(); code, err := w.Compile(fset, "1 + 2") if err != nil { fmt.Println("Compile error"); return } val, err := code.Run(); if err != nil { fmt.Println("Run time error"); return; } fmt.Println("Return value:", val) }
Change the programming language of this snippet from Java to Go without modifying what it does.
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStream; import java.lang.reflect.InvocationTargetException; import java.net.URI; import java.util.HashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; import javax.tools.FileObject; import javax.tools.ForwardingJavaFileManager; import javax.tools.JavaCompiler; import javax.tools.JavaFileObject; import javax.tools.SimpleJavaFileObject; import javax.tools.StandardJavaFileManager; import javax.tools.StandardLocation; import javax.tools.ToolProvider; public class Evaluator{ public static void main(String[] args){ new Evaluator().eval( "SayHello", "public class SayHello{public void speak(){System.out.println(\"Hello world\");}}", "speak" ); } void eval(String className, String classCode, String methodName){ Map<String, ByteArrayOutputStream> classCache = new HashMap<>(); JavaCompiler compiler = ToolProvider.getSystemJavaCompiler(); if ( null == compiler ) throw new RuntimeException("Could not get a compiler."); StandardJavaFileManager sfm = compiler.getStandardFileManager(null, null, null); ForwardingJavaFileManager<StandardJavaFileManager> fjfm = new ForwardingJavaFileManager<StandardJavaFileManager>(sfm){ @Override public JavaFileObject getJavaFileForOutput(Location location, String className, JavaFileObject.Kind kind, FileObject sibling) throws IOException{ if (StandardLocation.CLASS_OUTPUT == location && JavaFileObject.Kind.CLASS == kind) return new SimpleJavaFileObject(URI.create("mem: @Override public OutputStream openOutputStream() throws IOException{ ByteArrayOutputStream baos = new ByteArrayOutputStream(); classCache.put(className, baos); return baos; } }; else throw new IllegalArgumentException("Unexpected output file requested: " + location + ", " + className + ", " + kind); } }; List<JavaFileObject> files = new LinkedList<JavaFileObject>(){{ add( new SimpleJavaFileObject(URI.create("string: @Override public CharSequence getCharContent(boolean ignoreEncodingErrors){ return classCode; } } ); }}; compiler.getTask(null, fjfm, null, null, null, files).call(); try{ Class<?> clarse = new ClassLoader(){ @Override public Class<?> findClass(String name){ if (! name.startsWith(className)) throw new IllegalArgumentException("This class loader is for " + className + " - could not handle \"" + name + '"'); byte[] bytes = classCache.get(name).toByteArray(); return defineClass(name, bytes, 0, bytes.length); } }.loadClass(className); clarse.getMethod(methodName).invoke(clarse.newInstance()); }catch(ClassNotFoundException | InstantiationException | IllegalAccessException | NoSuchMethodException | InvocationTargetException x){ throw new RuntimeException("Run failed: " + x, x); } } }
package main import ( "fmt" "bitbucket.org/binet/go-eval/pkg/eval" "go/token" ) func main() { w := eval.NewWorld(); fset := token.NewFileSet(); code, err := w.Compile(fset, "1 + 2") if err != nil { fmt.Println("Compile error"); return } val, err := code.Run(); if err != nil { fmt.Println("Run time error"); return; } fmt.Println("Return value:", val) }
Change the following Java code into Go without altering its purpose.
import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.TreeMap; public class PisanoPeriod { public static void main(String[] args) { System.out.printf("Print pisano(p^2) for every prime p lower than 15%n"); for ( long i = 2 ; i < 15 ; i++ ) { if ( isPrime(i) ) { long n = i*i; System.out.printf("pisano(%d) = %d%n", n, pisano(n)); } } System.out.printf("%nPrint pisano(p) for every prime p lower than 180%n"); for ( long n = 2 ; n < 180 ; n++ ) { if ( isPrime(n) ) { System.out.printf("pisano(%d) = %d%n", n, pisano(n)); } } System.out.printf("%nPrint pisano(n) for every integer from 1 to 180%n"); for ( long n = 1 ; n <= 180 ; n++ ) { System.out.printf("%3d ", pisano(n)); if ( n % 10 == 0 ) { System.out.printf("%n"); } } } private static final boolean isPrime(long test) { if ( test == 2 ) { return true; } if ( test % 2 == 0 ) { return false; } for ( long i = 3 ; i <= Math.sqrt(test) ; i += 2 ) { if ( test % i == 0 ) { return false; } } return true; } private static Map<Long,Long> PERIOD_MEMO = new HashMap<>(); static { PERIOD_MEMO.put(2L, 3L); PERIOD_MEMO.put(3L, 8L); PERIOD_MEMO.put(5L, 20L); } private static long pisano(long n) { if ( PERIOD_MEMO.containsKey(n) ) { return PERIOD_MEMO.get(n); } if ( n == 1 ) { return 1; } Map<Long,Long> factors = getFactors(n); if ( factors.size() == 1 & factors.get(2L) != null && factors.get(2L) > 0 ) { long result = 3 * n / 2; PERIOD_MEMO.put(n, result); return result; } if ( factors.size() == 1 & factors.get(5L) != null && factors.get(5L) > 0 ) { long result = 4*n; PERIOD_MEMO.put(n, result); return result; } if ( factors.size() == 2 & factors.get(2L) != null && factors.get(2L) == 1 && factors.get(5L) != null && factors.get(5L) > 0 ) { long result = 6*n; PERIOD_MEMO.put(n, result); return result; } List<Long> primes = new ArrayList<>(factors.keySet()); long prime = primes.get(0); if ( factors.size() == 1 && factors.get(prime) == 1 ) { List<Long> divisors = new ArrayList<>(); if ( n % 10 == 1 || n % 10 == 9 ) { for ( long divisor : getDivisors(prime-1) ) { if ( divisor % 2 == 0 ) { divisors.add(divisor); } } } else { List<Long> pPlus1Divisors = getDivisors(prime+1); for ( long divisor : getDivisors(2*prime+2) ) { if ( ! pPlus1Divisors.contains(divisor) ) { divisors.add(divisor); } } } Collections.sort(divisors); for ( long divisor : divisors ) { if ( fibModIdentity(divisor, prime) ) { PERIOD_MEMO.put(prime, divisor); return divisor; } } throw new RuntimeException("ERROR 144: Divisor not found."); } long period = (long) Math.pow(prime, factors.get(prime)-1) * pisano(prime); for ( int i = 1 ; i < primes.size() ; i++ ) { prime = primes.get(i); period = lcm(period, (long) Math.pow(prime, factors.get(prime)-1) * pisano(prime)); } PERIOD_MEMO.put(n, period); return period; } private static boolean fibModIdentity(long n, long mod) { long aRes = 0; long bRes = 1; long cRes = 1; long aBase = 0; long bBase = 1; long cBase = 1; while ( n > 0 ) { if ( n % 2 == 1 ) { long temp1 = 0, temp2 = 0, temp3 = 0; if ( aRes > SQRT || aBase > SQRT || bRes > SQRT || bBase > SQRT || cBase > SQRT || cRes > SQRT ) { temp1 = (multiply(aRes, aBase, mod) + multiply(bRes, bBase, mod)) % mod; temp2 = (multiply(aBase, bRes, mod) + multiply(bBase, cRes, mod)) % mod; temp3 = (multiply(bBase, bRes, mod) + multiply(cBase, cRes, mod)) % mod; } else { temp1 = ((aRes*aBase % mod) + (bRes*bBase % mod)) % mod; temp2 = ((aBase*bRes % mod) + (bBase*cRes % mod)) % mod; temp3 = ((bBase*bRes % mod) + (cBase*cRes % mod)) % mod; } aRes = temp1; bRes = temp2; cRes = temp3; } n >>= 1L; long temp1 = 0, temp2 = 0, temp3 = 0; if ( aBase > SQRT || bBase > SQRT || cBase > SQRT ) { temp1 = (multiply(aBase, aBase, mod) + multiply(bBase, bBase, mod)) % mod; temp2 = (multiply(aBase, bBase, mod) + multiply(bBase, cBase, mod)) % mod; temp3 = (multiply(bBase, bBase, mod) + multiply(cBase, cBase, mod)) % mod; } else { temp1 = ((aBase*aBase % mod) + (bBase*bBase % mod)) % mod; temp2 = ((aBase*bBase % mod) + (bBase*cBase % mod)) % mod; temp3 = ((bBase*bBase % mod) + (cBase*cBase % mod)) % mod; } aBase = temp1; bBase = temp2; cBase = temp3; } return aRes % mod == 0 && bRes % mod == 1 && cRes % mod == 1; } private static final long SQRT = (long) Math.sqrt(Long.MAX_VALUE); public static final long multiply(long a, long b, long modulus) { long x = 0; long y = a % modulus; long t; while ( b > 0 ) { if ( b % 2 == 1 ) { t = x + y; x = (t > modulus ? t-modulus : t); } t = y << 1; y = (t > modulus ? t-modulus : t); b >>= 1; } return x % modulus; } private static final List<Long> getDivisors(long number) { List<Long> divisors = new ArrayList<>(); long sqrt = (long) Math.sqrt(number); for ( long i = 1 ; i <= sqrt ; i++ ) { if ( number % i == 0 ) { divisors.add(i); long div = number / i; if ( div != i ) { divisors.add(div); } } } return divisors; } public static long lcm(long a, long b) { return a*b/gcd(a,b); } public static long gcd(long a, long b) { if ( b == 0 ) { return a; } return gcd(b, a%b); } private static final Map<Long,Map<Long,Long>> allFactors = new TreeMap<Long,Map<Long,Long>>(); static { Map<Long,Long> factors = new TreeMap<Long,Long>(); factors.put(2L, 1L); allFactors.put(2L, factors); } public static Long MAX_ALL_FACTORS = 100000L; public static final Map<Long,Long> getFactors(Long number) { if ( allFactors.containsKey(number) ) { return allFactors.get(number); } Map<Long,Long> factors = new TreeMap<Long,Long>(); if ( number % 2 == 0 ) { Map<Long,Long> factorsdDivTwo = getFactors(number/2); factors.putAll(factorsdDivTwo); factors.merge(2L, 1L, (v1, v2) -> v1 + v2); if ( number < MAX_ALL_FACTORS ) { allFactors.put(number, factors); } return factors; } boolean prime = true; long sqrt = (long) Math.sqrt(number); for ( long i = 3 ; i <= sqrt ; i += 2 ) { if ( number % i == 0 ) { prime = false; factors.putAll(getFactors(number/i)); factors.merge(i, 1L, (v1, v2) -> v1 + v2); if ( number < MAX_ALL_FACTORS ) { allFactors.put(number, factors); } return factors; } } if ( prime ) { factors.put(number, 1L); if ( number < MAX_ALL_FACTORS ) { allFactors.put(number, factors); } } return factors; } }
package main import "fmt" func gcd(a, b uint) uint { if b == 0 { return a } return gcd(b, a%b) } func lcm(a, b uint) uint { return a / gcd(a, b) * b } func ipow(x, p uint) uint { prod := uint(1) for p > 0 { if p&1 != 0 { prod *= x } p >>= 1 x *= x } return prod } func getPrimes(n uint) []uint { var primes []uint for i := uint(2); i <= n; i++ { div := n / i mod := n % i for mod == 0 { primes = append(primes, i) n = div div = n / i mod = n % i } } return primes } func isPrime(n uint) bool { switch { case n < 2: return false case n%2 == 0: return n == 2 case n%3 == 0: return n == 3 default: d := uint(5) for d*d <= n { if n%d == 0 { return false } d += 2 if n%d == 0 { return false } d += 4 } return true } } func pisanoPeriod(m uint) uint { var p, c uint = 0, 1 for i := uint(0); i < m*m; i++ { p, c = c, (p+c)%m if p == 0 && c == 1 { return i + 1 } } return 1 } func pisanoPrime(p uint, k uint) uint { if !isPrime(p) || k == 0 { return 0 } return ipow(p, k-1) * pisanoPeriod(p) } func pisano(m uint) uint { primes := getPrimes(m) primePowers := make(map[uint]uint) for _, p := range primes { primePowers[p]++ } var pps []uint for k, v := range primePowers { pps = append(pps, pisanoPrime(k, v)) } if len(pps) == 0 { return 1 } if len(pps) == 1 { return pps[0] } f := pps[0] for i := 1; i < len(pps); i++ { f = lcm(f, pps[i]) } return f } func main() { for p := uint(2); p < 15; p++ { pp := pisanoPrime(p, 2) if pp > 0 { fmt.Printf("pisanoPrime(%2d: 2) = %d\n", p, pp) } } fmt.Println() for p := uint(2); p < 180; p++ { pp := pisanoPrime(p, 1) if pp > 0 { fmt.Printf("pisanoPrime(%3d: 1) = %d\n", p, pp) } } fmt.Println() fmt.Println("pisano(n) for integers 'n' from 1 to 180 are:") for n := uint(1); n <= 180; n++ { fmt.Printf("%3d ", pisano(n)) if n != 1 && n%15 == 0 { fmt.Println() } } fmt.Println() }
Change the programming language of this snippet from Java to Go without modifying what it does.
package railwaycircuit; import static java.util.Arrays.stream; import java.util.*; import static java.util.stream.IntStream.range; public class RailwayCircuit { final static int RIGHT = 1, LEFT = -1, STRAIGHT = 0; static String normalize(int[] tracks) { char[] a = new char[tracks.length]; for (int i = 0; i < a.length; i++) a[i] = "abc".charAt(tracks[i] + 1); String norm = new String(a); for (int i = 0, len = a.length; i < len; i++) { String s = new String(a); if (s.compareTo(norm) < 0) norm = s; char tmp = a[0]; for (int j = 1; j < a.length; j++) a[j - 1] = a[j]; a[len - 1] = tmp; } return norm; } static boolean fullCircleStraight(int[] tracks, int nStraight) { if (nStraight == 0) return true; if (stream(tracks).filter(i -> i == STRAIGHT).count() != nStraight) return false; int[] straight = new int[12]; for (int i = 0, idx = 0; i < tracks.length && idx >= 0; i++) { if (tracks[i] == STRAIGHT) straight[idx % 12]++; idx += tracks[i]; } return !(range(0, 6).anyMatch(i -> straight[i] != straight[i + 6]) && range(0, 8).anyMatch(i -> straight[i] != straight[i + 4])); } static boolean fullCircleRight(int[] tracks) { if (stream(tracks).map(i -> i * 30).sum() % 360 != 0) return false; int[] rTurns = new int[12]; for (int i = 0, idx = 0; i < tracks.length && idx >= 0; i++) { if (tracks[i] == RIGHT) rTurns[idx % 12]++; idx += tracks[i]; } return !(range(0, 6).anyMatch(i -> rTurns[i] != rTurns[i + 6]) && range(0, 8).anyMatch(i -> rTurns[i] != rTurns[i + 4])); } static void circuits(int nCurved, int nStraight) { Map<String, int[]> solutions = new HashMap<>(); PermutationsGen gen = getPermutationsGen(nCurved, nStraight); while (gen.hasNext()) { int[] tracks = gen.next(); if (!fullCircleStraight(tracks, nStraight)) continue; if (!fullCircleRight(tracks)) continue; solutions.put(normalize(tracks), tracks.clone()); } report(solutions, nCurved, nStraight); } static PermutationsGen getPermutationsGen(int nCurved, int nStraight) { assert (nCurved + nStraight - 12) % 4 == 0 : "input must be 12 + k * 4"; int[] trackTypes = new int[]{RIGHT, LEFT}; if (nStraight != 0) { if (nCurved == 12) trackTypes = new int[]{RIGHT, STRAIGHT}; else trackTypes = new int[]{RIGHT, LEFT, STRAIGHT}; } return new PermutationsGen(nCurved + nStraight, trackTypes); } static void report(Map<String, int[]> sol, int numC, int numS) { int size = sol.size(); System.out.printf("%n%d solution(s) for C%d,%d %n", size, numC, numS); if (size < 10) sol.values().stream().forEach(tracks -> { stream(tracks).forEach(i -> System.out.printf("%2d ", i)); System.out.println(); }); } public static void main(String[] args) { circuits(12, 0); circuits(16, 0); circuits(20, 0); circuits(24, 0); circuits(12, 4); } } class PermutationsGen { private int[] indices; private int[] choices; private int[] sequence; private int carry; PermutationsGen(int numPositions, int[] choices) { indices = new int[numPositions]; sequence = new int[numPositions]; this.choices = choices; } int[] next() { carry = 1; for (int i = 1; i < indices.length && carry > 0; i++) { indices[i] += carry; carry = 0; if (indices[i] == choices.length) { carry = 1; indices[i] = 0; } } for (int i = 0; i < indices.length; i++) sequence[i] = choices[indices[i]]; return sequence; } boolean hasNext() { return carry != 1; } }
package main import "fmt" const ( right = 1 left = -1 straight = 0 ) func normalize(tracks []int) string { size := len(tracks) a := make([]byte, size) for i := 0; i < size; i++ { a[i] = "abc"[tracks[i]+1] } norm := string(a) for i := 0; i < size; i++ { s := string(a) if s < norm { norm = s } tmp := a[0] copy(a, a[1:]) a[size-1] = tmp } return norm } func fullCircleStraight(tracks []int, nStraight int) bool { if nStraight == 0 { return true } count := 0 for _, track := range tracks { if track == straight { count++ } } if count != nStraight { return false } var straightTracks [12]int for i, idx := 0, 0; i < len(tracks) && idx >= 0; i++ { if tracks[i] == straight { straightTracks[idx%12]++ } idx += tracks[i] } any1, any2 := false, false for i := 0; i <= 5; i++ { if straightTracks[i] != straightTracks[i+6] { any1 = true break } } for i := 0; i <= 7; i++ { if straightTracks[i] != straightTracks[i+4] { any2 = true break } } return !any1 || !any2 } func fullCircleRight(tracks []int) bool { sum := 0 for _, track := range tracks { sum += track * 30 } if sum%360 != 0 { return false } var rTurns [12]int for i, idx := 0, 0; i < len(tracks) && idx >= 0; i++ { if tracks[i] == right { rTurns[idx%12]++ } idx += tracks[i] } any1, any2 := false, false for i := 0; i <= 5; i++ { if rTurns[i] != rTurns[i+6] { any1 = true break } } for i := 0; i <= 7; i++ { if rTurns[i] != rTurns[i+4] { any2 = true break } } return !any1 || !any2 } func circuits(nCurved, nStraight int) { solutions := make(map[string][]int) gen := getPermutationsGen(nCurved, nStraight) for gen.hasNext() { tracks := gen.next() if !fullCircleStraight(tracks, nStraight) { continue } if !fullCircleRight(tracks) { continue } tracks2 := make([]int, len(tracks)) copy(tracks2, tracks) solutions[normalize(tracks)] = tracks2 } report(solutions, nCurved, nStraight) } func getPermutationsGen(nCurved, nStraight int) PermutationsGen { if (nCurved+nStraight-12)%4 != 0 { panic("input must be 12 + k * 4") } var trackTypes []int switch nStraight { case 0: trackTypes = []int{right, left} case 12: trackTypes = []int{right, straight} default: trackTypes = []int{right, left, straight} } return NewPermutationsGen(nCurved+nStraight, trackTypes) } func report(sol map[string][]int, numC, numS int) { size := len(sol) fmt.Printf("\n%d solution(s) for C%d,%d \n", size, numC, numS) if numC <= 20 { for _, tracks := range sol { for _, track := range tracks { fmt.Printf("%2d ", track) } fmt.Println() } } } type PermutationsGen struct { NumPositions int choices []int indices []int sequence []int carry int } func NewPermutationsGen(numPositions int, choices []int) PermutationsGen { indices := make([]int, numPositions) sequence := make([]int, numPositions) carry := 0 return PermutationsGen{numPositions, choices, indices, sequence, carry} } func (p *PermutationsGen) next() []int { p.carry = 1 for i := 1; i < len(p.indices) && p.carry > 0; i++ { p.indices[i] += p.carry p.carry = 0 if p.indices[i] == len(p.choices) { p.carry = 1 p.indices[i] = 0 } } for j := 0; j < len(p.indices); j++ { p.sequence[j] = p.choices[p.indices[j]] } return p.sequence } func (p *PermutationsGen) hasNext() bool { return p.carry != 1 } func main() { for n := 12; n <= 28; n += 4 { circuits(n, 0) } circuits(12, 4) }
Can you help me rewrite this code in Go instead of Java, keeping it the same logically?
import java.awt.Point; import java.util.*; import static java.util.Arrays.asList; import java.util.function.Function; import static java.util.Comparator.comparing; import static java.util.stream.Collectors.toList; public class FreePolyominoesEnum { static final List<Function<Point, Point>> transforms = new ArrayList<>(); static { transforms.add(p -> new Point(p.y, -p.x)); transforms.add(p -> new Point(-p.x, -p.y)); transforms.add(p -> new Point(-p.y, p.x)); transforms.add(p -> new Point(-p.x, p.y)); transforms.add(p -> new Point(-p.y, -p.x)); transforms.add(p -> new Point(p.x, -p.y)); transforms.add(p -> new Point(p.y, p.x)); } static Point findMinima(List<Point> poly) { return new Point( poly.stream().mapToInt(a -> a.x).min().getAsInt(), poly.stream().mapToInt(a -> a.y).min().getAsInt()); } static List<Point> translateToOrigin(List<Point> poly) { final Point min = findMinima(poly); poly.replaceAll(p -> new Point(p.x - min.x, p.y - min.y)); return poly; } static List<List<Point>> rotationsAndReflections(List<Point> poly) { List<List<Point>> lst = new ArrayList<>(); lst.add(poly); for (Function<Point, Point> t : transforms) lst.add(poly.stream().map(t).collect(toList())); return lst; } static Comparator<Point> byCoords = Comparator.<Point>comparingInt(p -> p.x) .thenComparingInt(p -> p.y); static List<Point> normalize(List<Point> poly) { return rotationsAndReflections(poly).stream() .map(lst -> translateToOrigin(lst)) .map(lst -> lst.stream().sorted(byCoords).collect(toList())) .min(comparing(Object::toString)) .get(); } static List<Point> neighborhoods(Point p) { return asList(new Point(p.x - 1, p.y), new Point(p.x + 1, p.y), new Point(p.x, p.y - 1), new Point(p.x, p.y + 1)); } static List<Point> concat(List<Point> lst, Point pt) { List<Point> r = new ArrayList<>(); r.addAll(lst); r.add(pt); return r; } static List<Point> newPoints(List<Point> poly) { return poly.stream() .flatMap(p -> neighborhoods(p).stream()) .filter(p -> !poly.contains(p)) .distinct() .collect(toList()); } static List<List<Point>> constructNextRank(List<Point> poly) { return newPoints(poly).stream() .map(p -> normalize(concat(poly, p))) .distinct() .collect(toList()); } static List<List<Point>> rank(int n) { if (n < 0) throw new IllegalArgumentException("n cannot be negative"); if (n < 2) { List<List<Point>> r = new ArrayList<>(); if (n == 1) r.add(asList(new Point(0, 0))); return r; } return rank(n - 1).stream() .parallel() .flatMap(lst -> constructNextRank(lst).stream()) .distinct() .collect(toList()); } public static void main(String[] args) { for (List<Point> poly : rank(5)) { for (Point p : poly) System.out.printf("(%d,%d) ", p.x, p.y); System.out.println(); } } }
package main import ( "fmt" "sort" ) type point struct{ x, y int } type polyomino []point type pointset map[point]bool func (p point) rotate90() point { return point{p.y, -p.x} } func (p point) rotate180() point { return point{-p.x, -p.y} } func (p point) rotate270() point { return point{-p.y, p.x} } func (p point) reflect() point { return point{-p.x, p.y} } func (p point) String() string { return fmt.Sprintf("(%d, %d)", p.x, p.y) } func (p point) contiguous() polyomino { return polyomino{point{p.x - 1, p.y}, point{p.x + 1, p.y}, point{p.x, p.y - 1}, point{p.x, p.y + 1}} } func (po polyomino) minima() (int, int) { minx := po[0].x miny := po[0].y for i := 1; i < len(po); i++ { if po[i].x < minx { minx = po[i].x } if po[i].y < miny { miny = po[i].y } } return minx, miny } func (po polyomino) translateToOrigin() polyomino { minx, miny := po.minima() res := make(polyomino, len(po)) for i, p := range po { res[i] = point{p.x - minx, p.y - miny} } sort.Slice(res, func(i, j int) bool { return res[i].x < res[j].x || (res[i].x == res[j].x && res[i].y < res[j].y) }) return res } func (po polyomino) rotationsAndReflections() []polyomino { rr := make([]polyomino, 8) for i := 0; i < 8; i++ { rr[i] = make(polyomino, len(po)) } copy(rr[0], po) for j := 0; j < len(po); j++ { rr[1][j] = po[j].rotate90() rr[2][j] = po[j].rotate180() rr[3][j] = po[j].rotate270() rr[4][j] = po[j].reflect() rr[5][j] = po[j].rotate90().reflect() rr[6][j] = po[j].rotate180().reflect() rr[7][j] = po[j].rotate270().reflect() } return rr } func (po polyomino) canonical() polyomino { rr := po.rotationsAndReflections() minr := rr[0].translateToOrigin() mins := minr.String() for i := 1; i < 8; i++ { r := rr[i].translateToOrigin() s := r.String() if s < mins { minr = r mins = s } } return minr } func (po polyomino) String() string { return fmt.Sprintf("%v", []point(po)) } func (po polyomino) toPointset() pointset { pset := make(pointset, len(po)) for _, p := range po { pset[p] = true } return pset } func (po polyomino) newPoints() polyomino { pset := po.toPointset() m := make(pointset) for _, p := range po { pts := p.contiguous() for _, pt := range pts { if !pset[pt] { m[pt] = true } } } poly := make(polyomino, 0, len(m)) for k := range m { poly = append(poly, k) } return poly } func (po polyomino) newPolys() []polyomino { pts := po.newPoints() res := make([]polyomino, len(pts)) for i, pt := range pts { poly := make(polyomino, len(po)) copy(poly, po) poly = append(poly, pt) res[i] = poly.canonical() } return res } var monomino = polyomino{point{0, 0}} var monominoes = []polyomino{monomino} func rank(n int) []polyomino { switch { case n < 0: panic("n cannot be negative. Program terminated.") case n == 0: return []polyomino{} case n == 1: return monominoes default: r := rank(n - 1) m := make(map[string]bool) var polys []polyomino for _, po := range r { for _, po2 := range po.newPolys() { if s := po2.String(); !m[s] { polys = append(polys, po2) m[s] = true } } } sort.Slice(polys, func(i, j int) bool { return polys[i].String() < polys[j].String() }) return polys } } func main() { const n = 5 fmt.Printf("All free polyominoes of rank %d:\n\n", n) for _, poly := range rank(n) { for _, pt := range poly { fmt.Printf("%s ", pt) } fmt.Println() } const k = 10 fmt.Printf("\nNumber of free polyominoes of ranks 1 to %d:\n", k) for i := 1; i <= k; i++ { fmt.Printf("%d ", len(rank(i))) } fmt.Println() }
Can you help me rewrite this code in Go instead of Java, keeping it the same logically?
package src; import java.io.BufferedReader; import java.io.FileReader; import java.net.URI; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.utils.URIBuilder; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.util.EntityUtils; public class EventGetter { String city = ""; String topic = ""; public String getEvent(String path_code,String key) throws Exception{ String responseString = ""; URI request = new URIBuilder() .setScheme("http") .setHost("api.meetup.com") .setPath(path_code) .setParameter("topic", topic) .setParameter("city", city) .setParameter("key", key) .build(); HttpGet get = new HttpGet(request); System.out.println("Get request : "+get.toString()); CloseableHttpClient client = HttpClients.createDefault(); CloseableHttpResponse response = client.execute(get); responseString = EntityUtils.toString(response.getEntity()); return responseString; } public String getApiKey(String key_path){ String key = ""; try{ BufferedReader reader = new BufferedReader(new FileReader(key_path)); key = reader.readLine().toString(); reader.close(); } catch(Exception e){System.out.println(e.toString());} return key; } }
package main import ( "bytes" "encoding/json" "fmt" "io/ioutil" "log" "net/http" "net/url" "os" "strings" "time" ) var key string func init() { const keyFile = "api_key.txt" f, err := os.Open(keyFile) if err != nil { log.Fatal(err) } keydata, err := ioutil.ReadAll(f) if err != nil { log.Fatal(err) } key = strings.TrimSpace(string(keydata)) } type EventResponse struct { Results []Result } type Result struct { ID string Status string Name string EventURL string `json:"event_url"` Description string Time EventTime } type EventTime struct{ time.Time } func (et *EventTime) UnmarshalJSON(data []byte) error { var msec int64 if err := json.Unmarshal(data, &msec); err != nil { return err } et.Time = time.Unix(0, msec*int64(time.Millisecond)) return nil } func (et EventTime) MarshalJSON() ([]byte, error) { msec := et.UnixNano() / int64(time.Millisecond) return json.Marshal(msec) } func (r *Result) String() string { var b bytes.Buffer fmt.Fprintln(&b, "ID:", r.ID) fmt.Fprintln(&b, "URL:", r.EventURL) fmt.Fprintln(&b, "Time:", r.Time.Format(time.UnixDate)) d := r.Description const limit = 65 if len(d) > limit { d = d[:limit-1] + "…" } fmt.Fprintln(&b, "Description:", d) return b.String() } func main() { v := url.Values{ "topic": []string{"photo"}, "time": []string{",1w"}, "key": []string{key}, } u := url.URL{ Scheme: "http", Host: "api.meetup.com", Path: "2/open_events.json", RawQuery: v.Encode(), } resp, err := http.Get(u.String()) if err != nil { log.Fatal(err) } defer resp.Body.Close() log.Println("HTTP Status:", resp.Status) body, err := ioutil.ReadAll(resp.Body) if err != nil { log.Fatal(err) } var buf bytes.Buffer if err = json.Indent(&buf, body, "", " "); err != nil { log.Fatal(err) } var evresp EventResponse json.Unmarshal(body, &evresp) fmt.Println("Got", len(evresp.Results), "events") if len(evresp.Results) > 0 { fmt.Println("First event:\n", &evresp.Results[0]) } }
Port the provided Java code into Go while preserving the original functionality.
public class LogicPuzzle { boolean S[] = new boolean[13]; int Count = 0; public boolean check2 () { int count = 0; for (int k = 7; k <= 12; k++) if (S[k]) count++; return S[2] == (count == 3); } public boolean check3 () { int count = 0; for (int k = 2; k <= 12; k += 2) if (S[k]) count++; return S[3] == (count == 2); } public boolean check4 () { return S[4] == ( !S[5] || S[6] && S[7]); } public boolean check5 () { return S[5] == ( !S[2] && !S[3] && !S[4]); } public boolean check6 () { int count = 0; for (int k = 1; k <= 11; k += 2) if (S[k]) count++; return S[6] == (count == 4); } public boolean check7 () { return S[7] == ((S[2] || S[3]) && !(S[2] && S[3])); } public boolean check8 () { return S[8] == ( !S[7] || S[5] && S[6]); } public boolean check9 () { int count = 0; for (int k = 1; k <= 6; k++) if (S[k]) count++; return S[9] == (count == 3); } public boolean check10 () { return S[10] == (S[11] && S[12]); } public boolean check11 () { int count = 0; for (int k = 7; k <= 9; k++) if (S[k]) count++; return S[11] == (count == 1); } public boolean check12 () { int count = 0; for (int k = 1; k <= 11; k++) if (S[k]) count++; return S[12] == (count == 4); } public void check () { if (check2() && check3() && check4() && check5() && check6() && check7() && check8() && check9() && check10() && check11() && check12()) { for (int k = 1; k <= 12; k++) if (S[k]) System.out.print(k + " "); System.out.println(); Count++; } } public void recurseAll (int k) { if (k == 13) check(); else { S[k] = false; recurseAll(k + 1); S[k] = true; recurseAll(k + 1); } } public static void main (String args[]) { LogicPuzzle P = new LogicPuzzle(); P.S[1] = true; P.recurseAll(2); System.out.println(); System.out.println(P.Count + " Solutions found."); } }
package main import "fmt" var solution = make(chan int) var nearMiss = make(chan int) var done = make(chan bool) func main() { for i := 0; i < 4096; i++ { go checkPerm(i) } var ms []int for i := 0; i < 4096; { select { case <-done: i++ case s := <-solution: print12("solution", s) case m := <-nearMiss: ms = append(ms, m) } } for _, m := range ms { print12("near miss", m) } } func print12(label string, bits int) { fmt.Print(label, ":") for i := 1; i <= 12; i++ { if bits&1 == 1 { fmt.Print(" ", i) } bits >>= 1 } fmt.Println() } func checkPerm(tz int) { ts := func(n uint) bool { return tz>>(n-1)&1 == 1 } ntrue := func(xs ...uint) int { nt := 0 for _, x := range xs { if ts(x) { nt++ } } return nt } var con bool test := func(statement uint, b bool) { switch { case ts(statement) == b: case con: panic("bail") default: con = true } } defer func() { if x := recover(); x != nil { if msg, ok := x.(string); !ok && msg != "bail" { panic(x) } } done <- true }() test(1, true) test(2, ntrue(7, 8, 9, 10, 11, 12) == 3) test(3, ntrue(2, 4, 6, 8, 10, 12) == 2) test(4, !ts(5) || ts(6) && ts(7)) test(5, !ts(4) && !ts(3) && !ts(2)) test(6, ntrue(1, 3, 5, 7, 9, 11) == 4) test(7, ts(2) != ts(3)) test(8, !ts(7) || ts(5) && ts(6)) test(9, ntrue(1, 2, 3, 4, 5, 6) == 3) test(10, ts(11) && ts(12)) test(11, ntrue(7, 8, 9) == 1) test(12, ntrue(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) == 4) if con { nearMiss <- tz } else { solution <- tz } }
Convert the following code from Java to Go, ensuring the logic remains intact.
public class LogicPuzzle { boolean S[] = new boolean[13]; int Count = 0; public boolean check2 () { int count = 0; for (int k = 7; k <= 12; k++) if (S[k]) count++; return S[2] == (count == 3); } public boolean check3 () { int count = 0; for (int k = 2; k <= 12; k += 2) if (S[k]) count++; return S[3] == (count == 2); } public boolean check4 () { return S[4] == ( !S[5] || S[6] && S[7]); } public boolean check5 () { return S[5] == ( !S[2] && !S[3] && !S[4]); } public boolean check6 () { int count = 0; for (int k = 1; k <= 11; k += 2) if (S[k]) count++; return S[6] == (count == 4); } public boolean check7 () { return S[7] == ((S[2] || S[3]) && !(S[2] && S[3])); } public boolean check8 () { return S[8] == ( !S[7] || S[5] && S[6]); } public boolean check9 () { int count = 0; for (int k = 1; k <= 6; k++) if (S[k]) count++; return S[9] == (count == 3); } public boolean check10 () { return S[10] == (S[11] && S[12]); } public boolean check11 () { int count = 0; for (int k = 7; k <= 9; k++) if (S[k]) count++; return S[11] == (count == 1); } public boolean check12 () { int count = 0; for (int k = 1; k <= 11; k++) if (S[k]) count++; return S[12] == (count == 4); } public void check () { if (check2() && check3() && check4() && check5() && check6() && check7() && check8() && check9() && check10() && check11() && check12()) { for (int k = 1; k <= 12; k++) if (S[k]) System.out.print(k + " "); System.out.println(); Count++; } } public void recurseAll (int k) { if (k == 13) check(); else { S[k] = false; recurseAll(k + 1); S[k] = true; recurseAll(k + 1); } } public static void main (String args[]) { LogicPuzzle P = new LogicPuzzle(); P.S[1] = true; P.recurseAll(2); System.out.println(); System.out.println(P.Count + " Solutions found."); } }
package main import "fmt" var solution = make(chan int) var nearMiss = make(chan int) var done = make(chan bool) func main() { for i := 0; i < 4096; i++ { go checkPerm(i) } var ms []int for i := 0; i < 4096; { select { case <-done: i++ case s := <-solution: print12("solution", s) case m := <-nearMiss: ms = append(ms, m) } } for _, m := range ms { print12("near miss", m) } } func print12(label string, bits int) { fmt.Print(label, ":") for i := 1; i <= 12; i++ { if bits&1 == 1 { fmt.Print(" ", i) } bits >>= 1 } fmt.Println() } func checkPerm(tz int) { ts := func(n uint) bool { return tz>>(n-1)&1 == 1 } ntrue := func(xs ...uint) int { nt := 0 for _, x := range xs { if ts(x) { nt++ } } return nt } var con bool test := func(statement uint, b bool) { switch { case ts(statement) == b: case con: panic("bail") default: con = true } } defer func() { if x := recover(); x != nil { if msg, ok := x.(string); !ok && msg != "bail" { panic(x) } } done <- true }() test(1, true) test(2, ntrue(7, 8, 9, 10, 11, 12) == 3) test(3, ntrue(2, 4, 6, 8, 10, 12) == 2) test(4, !ts(5) || ts(6) && ts(7)) test(5, !ts(4) && !ts(3) && !ts(2)) test(6, ntrue(1, 3, 5, 7, 9, 11) == 4) test(7, ts(2) != ts(3)) test(8, !ts(7) || ts(5) && ts(6)) test(9, ntrue(1, 2, 3, 4, 5, 6) == 3) test(10, ts(11) && ts(12)) test(11, ntrue(7, 8, 9) == 1) test(12, ntrue(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) == 4) if con { nearMiss <- tz } else { solution <- tz } }
Write the same code in Go as shown below in Java.
import static java.lang.Math.*; import java.util.Arrays; import java.util.function.BiFunction; public class DemingsFunnel { public static void main(String[] args) { double[] dxs = { -0.533, 0.270, 0.859, -0.043, -0.205, -0.127, -0.071, 0.275, 1.251, -0.231, -0.401, 0.269, 0.491, 0.951, 1.150, 0.001, -0.382, 0.161, 0.915, 2.080, -2.337, 0.034, -0.126, 0.014, 0.709, 0.129, -1.093, -0.483, -1.193, 0.020, -0.051, 0.047, -0.095, 0.695, 0.340, -0.182, 0.287, 0.213, -0.423, -0.021, -0.134, 1.798, 0.021, -1.099, -0.361, 1.636, -1.134, 1.315, 0.201, 0.034, 0.097, -0.170, 0.054, -0.553, -0.024, -0.181, -0.700, -0.361, -0.789, 0.279, -0.174, -0.009, -0.323, -0.658, 0.348, -0.528, 0.881, 0.021, -0.853, 0.157, 0.648, 1.774, -1.043, 0.051, 0.021, 0.247, -0.310, 0.171, 0.000, 0.106, 0.024, -0.386, 0.962, 0.765, -0.125, -0.289, 0.521, 0.017, 0.281, -0.749, -0.149, -2.436, -0.909, 0.394, -0.113, -0.598, 0.443, -0.521, -0.799, 0.087}; double[] dys = { 0.136, 0.717, 0.459, -0.225, 1.392, 0.385, 0.121, -0.395, 0.490, -0.682, -0.065, 0.242, -0.288, 0.658, 0.459, 0.000, 0.426, 0.205, -0.765, -2.188, -0.742, -0.010, 0.089, 0.208, 0.585, 0.633, -0.444, -0.351, -1.087, 0.199, 0.701, 0.096, -0.025, -0.868, 1.051, 0.157, 0.216, 0.162, 0.249, -0.007, 0.009, 0.508, -0.790, 0.723, 0.881, -0.508, 0.393, -0.226, 0.710, 0.038, -0.217, 0.831, 0.480, 0.407, 0.447, -0.295, 1.126, 0.380, 0.549, -0.445, -0.046, 0.428, -0.074, 0.217, -0.822, 0.491, 1.347, -0.141, 1.230, -0.044, 0.079, 0.219, 0.698, 0.275, 0.056, 0.031, 0.421, 0.064, 0.721, 0.104, -0.729, 0.650, -1.103, 0.154, -1.720, 0.051, -0.385, 0.477, 1.537, -0.901, 0.939, -0.411, 0.341, -0.411, 0.106, 0.224, -0.947, -1.424, -0.542, -1.032}; experiment("Rule 1:", dxs, dys, (z, dz) -> 0.0); experiment("Rule 2:", dxs, dys, (z, dz) -> -dz); experiment("Rule 3:", dxs, dys, (z, dz) -> -(z + dz)); experiment("Rule 4:", dxs, dys, (z, dz) -> z + dz); } static void experiment(String label, double[] dxs, double[] dys, BiFunction<Double, Double, Double> rule) { double[] resx = funnel(dxs, rule); double[] resy = funnel(dys, rule); System.out.println(label); System.out.printf("Mean x, y:  %.4f, %.4f%n", mean(resx), mean(resy)); System.out.printf("Std dev x, y: %.4f, %.4f%n", stdDev(resx), stdDev(resy)); System.out.println(); } static double[] funnel(double[] input, BiFunction<Double, Double, Double> rule) { double x = 0; double[] result = new double[input.length]; for (int i = 0; i < input.length; i++) { double rx = x + input[i]; x = rule.apply(x, input[i]); result[i] = rx; } return result; } static double mean(double[] xs) { return Arrays.stream(xs).sum() / xs.length; } static double stdDev(double[] xs) { double m = mean(xs); return sqrt(Arrays.stream(xs).map(x -> pow((x - m), 2)).sum() / xs.length); } }
package main import ( "fmt" "math" ) type rule func(float64, float64) float64 var dxs = []float64{ -0.533, 0.270, 0.859, -0.043, -0.205, -0.127, -0.071, 0.275, 1.251, -0.231, -0.401, 0.269, 0.491, 0.951, 1.150, 0.001, -0.382, 0.161, 0.915, 2.080, -2.337, 0.034, -0.126, 0.014, 0.709, 0.129, -1.093, -0.483, -1.193, 0.020, -0.051, 0.047, -0.095, 0.695, 0.340, -0.182, 0.287, 0.213, -0.423, -0.021, -0.134, 1.798, 0.021, -1.099, -0.361, 1.636, -1.134, 1.315, 0.201, 0.034, 0.097, -0.170, 0.054, -0.553, -0.024, -0.181, -0.700, -0.361, -0.789, 0.279, -0.174, -0.009, -0.323, -0.658, 0.348, -0.528, 0.881, 0.021, -0.853, 0.157, 0.648, 1.774, -1.043, 0.051, 0.021, 0.247, -0.310, 0.171, 0.000, 0.106, 0.024, -0.386, 0.962, 0.765, -0.125, -0.289, 0.521, 0.017, 0.281, -0.749, -0.149, -2.436, -0.909, 0.394, -0.113, -0.598, 0.443, -0.521, -0.799, 0.087, } var dys = []float64{ 0.136, 0.717, 0.459, -0.225, 1.392, 0.385, 0.121, -0.395, 0.490, -0.682, -0.065, 0.242, -0.288, 0.658, 0.459, 0.000, 0.426, 0.205, -0.765, -2.188, -0.742, -0.010, 0.089, 0.208, 0.585, 0.633, -0.444, -0.351, -1.087, 0.199, 0.701, 0.096, -0.025, -0.868, 1.051, 0.157, 0.216, 0.162, 0.249, -0.007, 0.009, 0.508, -0.790, 0.723, 0.881, -0.508, 0.393, -0.226, 0.710, 0.038, -0.217, 0.831, 0.480, 0.407, 0.447, -0.295, 1.126, 0.380, 0.549, -0.445, -0.046, 0.428, -0.074, 0.217, -0.822, 0.491, 1.347, -0.141, 1.230, -0.044, 0.079, 0.219, 0.698, 0.275, 0.056, 0.031, 0.421, 0.064, 0.721, 0.104, -0.729, 0.650, -1.103, 0.154, -1.720, 0.051, -0.385, 0.477, 1.537, -0.901, 0.939, -0.411, 0.341, -0.411, 0.106, 0.224, -0.947, -1.424, -0.542, -1.032, } func funnel(fa []float64, r rule) []float64 { x := 0.0 result := make([]float64, len(fa)) for i, f := range fa { result[i] = x + f x = r(x, f) } return result } func mean(fa []float64) float64 { sum := 0.0 for _, f := range fa { sum += f } return sum / float64(len(fa)) } func stdDev(fa []float64) float64 { m := mean(fa) sum := 0.0 for _, f := range fa { sum += (f - m) * (f - m) } return math.Sqrt(sum / float64(len(fa))) } func experiment(label string, r rule) { rxs := funnel(dxs, r) rys := funnel(dys, r) fmt.Println(label, " : x y") fmt.Printf("Mean  : %7.4f, %7.4f\n", mean(rxs), mean(rys)) fmt.Printf("Std Dev : %7.4f, %7.4f\n", stdDev(rxs), stdDev(rys)) fmt.Println() } func main() { experiment("Rule 1", func(_, _ float64) float64 { return 0.0 }) experiment("Rule 2", func(_, dz float64) float64 { return -dz }) experiment("Rule 3", func(z, dz float64) float64 { return -(z + dz) }) experiment("Rule 4", func(z, dz float64) float64 { return z + dz }) }
Rewrite the snippet below in Go so it works the same as the original Java code.
import static java.lang.Math.*; import java.util.Arrays; import java.util.function.BiFunction; public class DemingsFunnel { public static void main(String[] args) { double[] dxs = { -0.533, 0.270, 0.859, -0.043, -0.205, -0.127, -0.071, 0.275, 1.251, -0.231, -0.401, 0.269, 0.491, 0.951, 1.150, 0.001, -0.382, 0.161, 0.915, 2.080, -2.337, 0.034, -0.126, 0.014, 0.709, 0.129, -1.093, -0.483, -1.193, 0.020, -0.051, 0.047, -0.095, 0.695, 0.340, -0.182, 0.287, 0.213, -0.423, -0.021, -0.134, 1.798, 0.021, -1.099, -0.361, 1.636, -1.134, 1.315, 0.201, 0.034, 0.097, -0.170, 0.054, -0.553, -0.024, -0.181, -0.700, -0.361, -0.789, 0.279, -0.174, -0.009, -0.323, -0.658, 0.348, -0.528, 0.881, 0.021, -0.853, 0.157, 0.648, 1.774, -1.043, 0.051, 0.021, 0.247, -0.310, 0.171, 0.000, 0.106, 0.024, -0.386, 0.962, 0.765, -0.125, -0.289, 0.521, 0.017, 0.281, -0.749, -0.149, -2.436, -0.909, 0.394, -0.113, -0.598, 0.443, -0.521, -0.799, 0.087}; double[] dys = { 0.136, 0.717, 0.459, -0.225, 1.392, 0.385, 0.121, -0.395, 0.490, -0.682, -0.065, 0.242, -0.288, 0.658, 0.459, 0.000, 0.426, 0.205, -0.765, -2.188, -0.742, -0.010, 0.089, 0.208, 0.585, 0.633, -0.444, -0.351, -1.087, 0.199, 0.701, 0.096, -0.025, -0.868, 1.051, 0.157, 0.216, 0.162, 0.249, -0.007, 0.009, 0.508, -0.790, 0.723, 0.881, -0.508, 0.393, -0.226, 0.710, 0.038, -0.217, 0.831, 0.480, 0.407, 0.447, -0.295, 1.126, 0.380, 0.549, -0.445, -0.046, 0.428, -0.074, 0.217, -0.822, 0.491, 1.347, -0.141, 1.230, -0.044, 0.079, 0.219, 0.698, 0.275, 0.056, 0.031, 0.421, 0.064, 0.721, 0.104, -0.729, 0.650, -1.103, 0.154, -1.720, 0.051, -0.385, 0.477, 1.537, -0.901, 0.939, -0.411, 0.341, -0.411, 0.106, 0.224, -0.947, -1.424, -0.542, -1.032}; experiment("Rule 1:", dxs, dys, (z, dz) -> 0.0); experiment("Rule 2:", dxs, dys, (z, dz) -> -dz); experiment("Rule 3:", dxs, dys, (z, dz) -> -(z + dz)); experiment("Rule 4:", dxs, dys, (z, dz) -> z + dz); } static void experiment(String label, double[] dxs, double[] dys, BiFunction<Double, Double, Double> rule) { double[] resx = funnel(dxs, rule); double[] resy = funnel(dys, rule); System.out.println(label); System.out.printf("Mean x, y:  %.4f, %.4f%n", mean(resx), mean(resy)); System.out.printf("Std dev x, y: %.4f, %.4f%n", stdDev(resx), stdDev(resy)); System.out.println(); } static double[] funnel(double[] input, BiFunction<Double, Double, Double> rule) { double x = 0; double[] result = new double[input.length]; for (int i = 0; i < input.length; i++) { double rx = x + input[i]; x = rule.apply(x, input[i]); result[i] = rx; } return result; } static double mean(double[] xs) { return Arrays.stream(xs).sum() / xs.length; } static double stdDev(double[] xs) { double m = mean(xs); return sqrt(Arrays.stream(xs).map(x -> pow((x - m), 2)).sum() / xs.length); } }
package main import ( "fmt" "math" ) type rule func(float64, float64) float64 var dxs = []float64{ -0.533, 0.270, 0.859, -0.043, -0.205, -0.127, -0.071, 0.275, 1.251, -0.231, -0.401, 0.269, 0.491, 0.951, 1.150, 0.001, -0.382, 0.161, 0.915, 2.080, -2.337, 0.034, -0.126, 0.014, 0.709, 0.129, -1.093, -0.483, -1.193, 0.020, -0.051, 0.047, -0.095, 0.695, 0.340, -0.182, 0.287, 0.213, -0.423, -0.021, -0.134, 1.798, 0.021, -1.099, -0.361, 1.636, -1.134, 1.315, 0.201, 0.034, 0.097, -0.170, 0.054, -0.553, -0.024, -0.181, -0.700, -0.361, -0.789, 0.279, -0.174, -0.009, -0.323, -0.658, 0.348, -0.528, 0.881, 0.021, -0.853, 0.157, 0.648, 1.774, -1.043, 0.051, 0.021, 0.247, -0.310, 0.171, 0.000, 0.106, 0.024, -0.386, 0.962, 0.765, -0.125, -0.289, 0.521, 0.017, 0.281, -0.749, -0.149, -2.436, -0.909, 0.394, -0.113, -0.598, 0.443, -0.521, -0.799, 0.087, } var dys = []float64{ 0.136, 0.717, 0.459, -0.225, 1.392, 0.385, 0.121, -0.395, 0.490, -0.682, -0.065, 0.242, -0.288, 0.658, 0.459, 0.000, 0.426, 0.205, -0.765, -2.188, -0.742, -0.010, 0.089, 0.208, 0.585, 0.633, -0.444, -0.351, -1.087, 0.199, 0.701, 0.096, -0.025, -0.868, 1.051, 0.157, 0.216, 0.162, 0.249, -0.007, 0.009, 0.508, -0.790, 0.723, 0.881, -0.508, 0.393, -0.226, 0.710, 0.038, -0.217, 0.831, 0.480, 0.407, 0.447, -0.295, 1.126, 0.380, 0.549, -0.445, -0.046, 0.428, -0.074, 0.217, -0.822, 0.491, 1.347, -0.141, 1.230, -0.044, 0.079, 0.219, 0.698, 0.275, 0.056, 0.031, 0.421, 0.064, 0.721, 0.104, -0.729, 0.650, -1.103, 0.154, -1.720, 0.051, -0.385, 0.477, 1.537, -0.901, 0.939, -0.411, 0.341, -0.411, 0.106, 0.224, -0.947, -1.424, -0.542, -1.032, } func funnel(fa []float64, r rule) []float64 { x := 0.0 result := make([]float64, len(fa)) for i, f := range fa { result[i] = x + f x = r(x, f) } return result } func mean(fa []float64) float64 { sum := 0.0 for _, f := range fa { sum += f } return sum / float64(len(fa)) } func stdDev(fa []float64) float64 { m := mean(fa) sum := 0.0 for _, f := range fa { sum += (f - m) * (f - m) } return math.Sqrt(sum / float64(len(fa))) } func experiment(label string, r rule) { rxs := funnel(dxs, r) rys := funnel(dys, r) fmt.Println(label, " : x y") fmt.Printf("Mean  : %7.4f, %7.4f\n", mean(rxs), mean(rys)) fmt.Printf("Std Dev : %7.4f, %7.4f\n", stdDev(rxs), stdDev(rys)) fmt.Println() } func main() { experiment("Rule 1", func(_, _ float64) float64 { return 0.0 }) experiment("Rule 2", func(_, dz float64) float64 { return -dz }) experiment("Rule 3", func(z, dz float64) float64 { return -(z + dz) }) experiment("Rule 4", func(z, dz float64) float64 { return z + dz }) }
Keep all operations the same but rewrite the snippet in Go.
import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.FileWriter; public class FixCodeTags { public static void main(String[] args) { String sourcefile=args[0]; String convertedfile=args[1]; convert(sourcefile,convertedfile); } static String[] languages = {"abap", "actionscript", "actionscript3", "ada", "apache", "applescript", "apt_sources", "asm", "asp", "autoit", "avisynth", "bar", "bash", "basic4gl", "bf", "blitzbasic", "bnf", "boo", "c", "caddcl", "cadlisp", "cfdg", "cfm", "cil", "c_mac", "cobol", "cpp", "cpp-qt", "csharp", "css", "d", "delphi", "diff", "_div", "dos", "dot", "eiffel", "email", "foo", "fortran", "freebasic", "genero", "gettext", "glsl", "gml", "gnuplot", "go", "groovy", "haskell", "hq9plus", "html4strict", "idl", "ini", "inno", "intercal", "io", "java", "java5", "javascript", "kixtart", "klonec", "klonecpp", "latex", "lisp", "lolcode", "lotusformulas", "lotusscript", "lscript", "lua", "m68k", "make", "matlab", "mirc", "modula3", "mpasm", "mxml", "mysql", "nsis", "objc", "ocaml", "ocaml-brief", "oobas", "oracle11", "oracle8", "pascal", "per", "perl", "php", "php-brief", "pic16", "pixelbender", "plsql", "povray", "powershell", "progress", "prolog", "providex", "python", "qbasic", "rails", "reg", "robots", "ruby", "sas", "scala", "scheme", "scilab", "sdlbasic", "smalltalk", "smarty", "sql", "tcl", "teraterm", "text", "thinbasic", "tsql", "typoscript", "vb", "vbnet", "verilog", "vhdl", "vim", "visualfoxpro", "visualprolog", "whitespace", "winbatch", "xml", "xorg_conf", "xpp", "z80"}; static void convert(String sourcefile,String convertedfile) { try { BufferedReader br=new BufferedReader(new FileReader(sourcefile)); StringBuffer sb=new StringBuffer(""); String line; while((line=br.readLine())!=null) { for(int i=0;i<languages.length;i++) { String lang=languages[i]; line=line.replaceAll("<"+lang+">", "<lang "+lang+">"); line=line.replaceAll("</"+lang+">", "</"+"lang>"); line=line.replaceAll("<code "+lang+">", "<lang "+lang+">"); line=line.replaceAll("</code>", "</"+"lang>"); } sb.append(line); } br.close(); FileWriter fw=new FileWriter(new File(convertedfile)); fw.write(sb.toString()); fw.close(); } catch (Exception e) { System.out.println("Something went horribly wrong: "+e.getMessage()); } } }
package main import "fmt" import "io/ioutil" import "log" import "os" import "regexp" import "strings" func main() { err := fix() if err != nil { log.Fatalln(err) } } func fix() (err error) { buf, err := ioutil.ReadAll(os.Stdin) if err != nil { return err } out, err := Lang(string(buf)) if err != nil { return err } fmt.Println(out) return nil } func Lang(in string) (out string, err error) { reg := regexp.MustCompile("<[^>]+>") out = reg.ReplaceAllStringFunc(in, repl) return out, nil } func repl(in string) (out string) { if in == "</code>" { return "</"+"lang>" } mid := in[1 : len(in)-1] var langs = []string{ "abap", "actionscript", "actionscript3", "ada", "apache", "applescript", "apt_sources", "asm", "asp", "autoit", "avisynth", "bash", "basic4gl", "bf", "blitzbasic", "bnf", "boo", "c", "caddcl", "cadlisp", "cfdg", "cfm", "cil", "c_mac", "cobol", "cpp", "cpp-qt", "csharp", "css", "d", "delphi", "diff", "_div", "dos", "dot", "eiffel", "email", "fortran", "freebasic", "genero", "gettext", "glsl", "gml", "gnuplot", "go", "groovy", "haskell", "hq9plus", "html4strict", "idl", "ini", "inno", "intercal", "io", "java", "java5", "javascript", "kixtart", "klonec", "klonecpp", "latex", "lisp", "lolcode", "lotusformulas", "lotusscript", "lscript", "lua", "m68k", "make", "matlab", "mirc", "modula3", "mpasm", "mxml", "mysql", "nsis", "objc", "ocaml", "ocaml-brief", "oobas", "oracle11", "oracle8", "pascal", "per", "perl", "php", "php-brief", "pic16", "pixelbender", "plsql", "povray", "powershell", "progress", "prolog", "providex", "python", "qbasic", "rails", "reg", "robots", "ruby", "sas", "scala", "scheme", "scilab", "sdlbasic", "smalltalk", "smarty", "sql", "tcl", "teraterm", "text", "thinbasic", "tsql", "typoscript", "vb", "vbnet", "verilog", "vhdl", "vim", "visualfoxpro", "visualprolog", "whitespace", "winbatch", "xml", "xorg_conf", "xpp", "z80", } for _, lang := range langs { if mid == lang { return fmt.Sprintf("<lang %s>", lang) } if strings.HasPrefix(mid, "/") { if mid[len("/"):] == lang { return "</"+"lang>" } } if strings.HasPrefix(mid, "code ") { if mid[len("code "):] == lang { return fmt.Sprintf("<lang %s>", lang) } } } return in }
Change the programming language of this snippet from Java to Go without modifying what it does.
import java.util.function.Predicate; public class PermutationsWithRepetitions { public static void main(String[] args) { char[] chars = {'a', 'b', 'c', 'd'}; permute(chars, 3, i -> i[0] == 1 && i[1] == 1 && i[2] == 0); } static void permute(char[] a, int k, Predicate<int[]> decider) { int n = a.length; if (k < 1 || k > n) throw new IllegalArgumentException("Illegal number of positions."); int[] indexes = new int[n]; int total = (int) Math.pow(n, k); while (total-- > 0) { for (int i = 0; i < n - (n - k); i++) System.out.print(a[indexes[i]]); System.out.println(); if (decider.test(indexes)) break; for (int i = 0; i < n; i++) { if (indexes[i] >= n - 1) { indexes[i] = 0; } else { indexes[i]++; break; } } } } }
package main import "fmt" var ( n = 3 values = []string{"A", "B", "C", "D"} k = len(values) decide = func(p []string) bool { return p[0] == "B" && p[1] == "C" } ) func main() { pn := make([]int, n) p := make([]string, n) for { for i, x := range pn { p[i] = values[x] } fmt.Println(p) if decide(p) { return } for i := 0; ; { pn[i]++ if pn[i] < k { break } pn[i] = 0 i++ if i == n { return } } } }
Please provide an equivalent version of this Java code in Go.
import java.util.function.Predicate; public class PermutationsWithRepetitions { public static void main(String[] args) { char[] chars = {'a', 'b', 'c', 'd'}; permute(chars, 3, i -> i[0] == 1 && i[1] == 1 && i[2] == 0); } static void permute(char[] a, int k, Predicate<int[]> decider) { int n = a.length; if (k < 1 || k > n) throw new IllegalArgumentException("Illegal number of positions."); int[] indexes = new int[n]; int total = (int) Math.pow(n, k); while (total-- > 0) { for (int i = 0; i < n - (n - k); i++) System.out.print(a[indexes[i]]); System.out.println(); if (decider.test(indexes)) break; for (int i = 0; i < n; i++) { if (indexes[i] >= n - 1) { indexes[i] = 0; } else { indexes[i]++; break; } } } } }
package main import "fmt" var ( n = 3 values = []string{"A", "B", "C", "D"} k = len(values) decide = func(p []string) bool { return p[0] == "B" && p[1] == "C" } ) func main() { pn := make([]int, n) p := make([]string, n) for { for i, x := range pn { p[i] = values[x] } fmt.Println(p) if decide(p) { return } for i := 0; ; { pn[i]++ if pn[i] < k { break } pn[i] = 0 i++ if i == n { return } } } }
Rewrite the snippet below in Go so it works the same as the original Java code.
import java.util.function.Predicate; public class PermutationsWithRepetitions { public static void main(String[] args) { char[] chars = {'a', 'b', 'c', 'd'}; permute(chars, 3, i -> i[0] == 1 && i[1] == 1 && i[2] == 0); } static void permute(char[] a, int k, Predicate<int[]> decider) { int n = a.length; if (k < 1 || k > n) throw new IllegalArgumentException("Illegal number of positions."); int[] indexes = new int[n]; int total = (int) Math.pow(n, k); while (total-- > 0) { for (int i = 0; i < n - (n - k); i++) System.out.print(a[indexes[i]]); System.out.println(); if (decider.test(indexes)) break; for (int i = 0; i < n; i++) { if (indexes[i] >= n - 1) { indexes[i] = 0; } else { indexes[i]++; break; } } } } }
package main import "fmt" var ( n = 3 values = []string{"A", "B", "C", "D"} k = len(values) decide = func(p []string) bool { return p[0] == "B" && p[1] == "C" } ) func main() { pn := make([]int, n) p := make([]string, n) for { for i, x := range pn { p[i] = values[x] } fmt.Println(p) if decide(p) { return } for i := 0; ; { pn[i]++ if pn[i] < k { break } pn[i] = 0 i++ if i == n { return } } } }
Convert this Java snippet to Go and keep its semantics consistent.
import java.io.BufferedWriter; import java.io.FileWriter; import java.io.File; import java.io.IOException; import java.util.Scanner; class CopysJ { public static void main(String[] args) { String ddname_IN = "copys.in.txt"; String ddname_OUT = "copys.out.txt"; if (args.length >= 1) { ddname_IN = args[0].length() > 0 ? args[0] : ddname_IN; } if (args.length >= 2) { ddname_OUT = args[1].length() > 0 ? args[1] : ddname_OUT; } File dd_IN = new File(ddname_IN); File dd_OUT = new File(ddname_OUT); try ( Scanner scanner_IN = new Scanner(dd_IN); BufferedWriter writer_OUT = new BufferedWriter(new FileWriter(dd_OUT)) ) { String a; String b; String c; String d; String c1; String x = "XXXXX"; String data_IN; String data_OUT; int ib; while (scanner_IN.hasNextLine()) { data_IN = scanner_IN.nextLine(); ib = 0; a = data_IN.substring(ib, ib += 5); b = data_IN.substring(ib, ib += 5); c = data_IN.substring(ib, ib += 4); c1=Integer.toHexString(new Byte((c.getBytes())[0]).intValue()); if (c1.length()<2) { c1="0" + c1; } data_OUT = a + c1 + x; writer_OUT.write(data_OUT); writer_OUT.newLine(); System.out.println(data_IN); System.out.println(data_OUT); System.out.println(); } } catch (IOException ex) { ex.printStackTrace(); } return; } }
package main import ( "encoding/json" "log" "os" "bytes" "errors" "strings" ) type s1 struct { A string B string C int D string } type s2 struct { A string C intString X string } type intString string func (i *intString) UnmarshalJSON(b []byte) error { if len(b) == 0 || bytes.IndexByte([]byte("0123456789-"), b[0]) < 0 { return errors.New("Unmarshal intString expected JSON number") } *i = intString(b) return nil } func NewS2() *s2 { return &s2{X: "XXXXX"} } func main() { o1, err := os.Create("o1.json") if err != nil { log.Fatal(err) } e := json.NewEncoder(o1) for i := 1; i <= 5; i++ { err := e.Encode(s1{ strings.Repeat("A", i), strings.Repeat("B", i), i, strings.Repeat("D", i), }) if err != nil { log.Fatal(err) } } o1.Close() in, err := os.Open("o1.json") if err != nil { log.Fatal(err) } out, err := os.Create("out.json") if err != nil { log.Fatal(err) } d := json.NewDecoder(in) e = json.NewEncoder(out) for d.More() { s := NewS2() if err = d.Decode(s); err != nil { log.Fatal(err) } if err = e.Encode(s); err != nil { log.Fatal(err) } } }
Translate this program into Go but keep the logic exactly as in Java.
import java.util.function.IntPredicate; import java.util.stream.IntStream; public class Test { public static void main(String[] args) throws Exception { print("Java Identifier start: ", 0, 0x10FFFF, 72, Character::isJavaIdentifierStart, "%c"); print("Java Identifier part: ", 0, 0x10FFFF, 25, Character::isJavaIdentifierPart, "[%d]"); print("Identifier ignorable: ", 0, 0x10FFFF, 25, Character::isIdentifierIgnorable, "[%d]"); print("Unicode Identifier start: ", 0, 0x10FFFF, 72, Character::isUnicodeIdentifierStart, "%c"); print("Unicode Identifier part : ", 0, 0x10FFFF, 25, Character::isUnicodeIdentifierPart, "[%d]"); } static void print(String msg, int start, int end, int limit, IntPredicate p, String fmt) { System.out.print(msg); IntStream.rangeClosed(start, end) .filter(p) .limit(limit) .forEach(cp -> System.out.printf(fmt, cp)); System.out.println("..."); } }
package main import ( "fmt" "go/ast" "go/parser" "strings" "unicode" ) func isValidIdentifier(identifier string) bool { node, err := parser.ParseExpr(identifier) if err != nil { return false } ident, ok := node.(*ast.Ident) return ok && ident.Name == identifier } type runeRanges struct { ranges []string hasStart bool start rune end rune } func (r *runeRanges) add(cp rune) { if !r.hasStart { r.hasStart = true r.start = cp r.end = cp return } if cp == r.end+1 { r.end = cp return } r.writeTo(&r.ranges) r.start = cp r.end = cp } func (r *runeRanges) writeTo(ranges *[]string) { if r.hasStart { if r.start == r.end { *ranges = append(*ranges, fmt.Sprintf("%U", r.end)) } else { *ranges = append(*ranges, fmt.Sprintf("%U-%U", r.start, r.end)) } } } func (r *runeRanges) String() string { ranges := r.ranges r.writeTo(&ranges) return strings.Join(ranges, ", ") } func main() { var validFirst runeRanges var validFollow runeRanges var validOnlyFollow runeRanges for r := rune(0); r <= unicode.MaxRune; r++ { first := isValidIdentifier(string([]rune{r})) follow := isValidIdentifier(string([]rune{'_', r})) if first { validFirst.add(r) } if follow { validFollow.add(r) } if follow && !first { validOnlyFollow.add(r) } } _, _ = fmt.Println("Valid first:", validFirst.String()) _, _ = fmt.Println("Valid follow:", validFollow.String()) _, _ = fmt.Println("Only follow:", validOnlyFollow.String()) }
Change the programming language of this snippet from Java to Go without modifying what it does.
(...) int feedForward(double[] inputs) { assert inputs.length == weights.length : "weights and input length mismatch"; double sum = 0; for (int i = 0; i < weights.length; i++) { sum += inputs[i] * weights[i]; } return activate(sum); } (...)
func assert(t bool, s string) { if !t { panic(s) } } assert(c == 0, "some text here")
Convert the following code from Java to Go, ensuring the logic remains intact.
(...) int feedForward(double[] inputs) { assert inputs.length == weights.length : "weights and input length mismatch"; double sum = 0; for (int i = 0; i < weights.length; i++) { sum += inputs[i] * weights[i]; } return activate(sum); } (...)
func assert(t bool, s string) { if !t { panic(s) } } assert(c == 0, "some text here")
Translate the given Java code snippet into Go without altering its behavior.
module test { @Inject Console console; void run() { Char ch = 'x'; console.print( $"ch={ch.quoted()}"); String greeting = "Hello"; console.print( $"greeting={greeting.quoted()}"); String lines = \|first line |second line\ | continued ; console.print($|lines= |{lines} ); String name = "Bob"; String msg = $|{greeting} {name}, |Have a nice day! |{ch}{ch}{ch} ; console.print($|msg= |{msg} ); } }
package main import ( "fmt" "os" "regexp" "strconv" ) var ( rl1 = 'a' rl2 = '\'' ) var ( is1 = "abc" is2 = "\"ab\tc\"" ) var ( rs1 = ` first" second' third" ` rs2 = `This is one way of including a ` + "`" + ` in a raw string literal.` rs3 = `\d+` ) func main() { fmt.Println(rl1, rl2) fmt.Println(is1, is2) fmt.Println(rs1) fmt.Println(rs2) re := regexp.MustCompile(rs3) fmt.Println(re.FindString("abcd1234efgh")) n := 3 fmt.Printf("\nThere are %d quoting constructs in Go.\n", n) s := "constructs" fmt.Println("There are", n, "quoting", s, "in Go.") mapper := func(placeholder string) string { switch placeholder { case "NUMBER": return strconv.Itoa(n) case "TYPES": return s } return "" } fmt.Println(os.Expand("There are ${NUMBER} quoting ${TYPES} in Go.", mapper)) }
Write the same code in Python as shown below in C#.
using System; using System.Linq; namespace ChineseRemainderTheorem { class Program { static void Main(string[] args) { int[] n = { 3, 5, 7 }; int[] a = { 2, 3, 2 }; int result = ChineseRemainderTheorem.Solve(n, a); int counter = 0; int maxCount = n.Length - 1; while (counter <= maxCount) { Console.WriteLine($"{result} ≡ {a[counter]} (mod {n[counter]})"); counter++; } } } public static class ChineseRemainderTheorem { public static int Solve(int[] n, int[] a) { int prod = n.Aggregate(1, (i, j) => i * j); int p; int sm = 0; for (int i = 0; i < n.Length; i++) { p = prod / n[i]; sm += a[i] * ModularMultiplicativeInverse(p, n[i]) * p; } return sm % prod; } private static int ModularMultiplicativeInverse(int a, int mod) { int b = a % mod; for (int x = 1; x < mod; x++) { if ((b * x) % mod == 1) { return x; } } return 1; } } }
def chinese_remainder(n, a): sum = 0 prod = reduce(lambda a, b: a*b, n) for n_i, a_i in zip(n, a): p = prod / n_i sum += a_i * mul_inv(p, n_i) * p return sum % prod def mul_inv(a, b): b0 = b x0, x1 = 0, 1 if b == 1: return 1 while a > 1: q = a / b a, b = b, a%b x0, x1 = x1 - q * x0, x0 if x1 < 0: x1 += b0 return x1 if __name__ == '__main__': n = [3, 5, 7] a = [2, 3, 2] print chinese_remainder(n, a)
Change the programming language of this snippet from C# to Python without modifying what it does.
using System; using System.Numerics; namespace PiCalc { internal class Program { private readonly BigInteger FOUR = new BigInteger(4); private readonly BigInteger SEVEN = new BigInteger(7); private readonly BigInteger TEN = new BigInteger(10); private readonly BigInteger THREE = new BigInteger(3); private readonly BigInteger TWO = new BigInteger(2); private BigInteger k = BigInteger.One; private BigInteger l = new BigInteger(3); private BigInteger n = new BigInteger(3); private BigInteger q = BigInteger.One; private BigInteger r = BigInteger.Zero; private BigInteger t = BigInteger.One; public void CalcPiDigits() { BigInteger nn, nr; bool first = true; while (true) { if ((FOUR*q + r - t).CompareTo(n*t) == -1) { Console.Write(n); if (first) { Console.Write("."); first = false; } nr = TEN*(r - (n*t)); n = TEN*(THREE*q + r)/t - (TEN*n); q *= TEN; r = nr; } else { nr = (TWO*q + r)*l; nn = (q*(SEVEN*k) + TWO + r*l)/(t*l); q *= k; t *= l; l += TWO; k += BigInteger.One; n = nn; r = nr; } } } private static void Main(string[] args) { new Program().CalcPiDigits(); } } }
def calcPi(): q, r, t, k, n, l = 1, 0, 1, 1, 3, 3 while True: if 4*q+r-t < n*t: yield n nr = 10*(r-n*t) n = ((10*(3*q+r))//t)-10*n q *= 10 r = nr else: nr = (2*q+r)*l nn = (q*(7*k)+2+(r*l))//(t*l) q *= k t *= l l += 2 k += 1 n = nn r = nr import sys pi_digits = calcPi() i = 0 for d in pi_digits: sys.stdout.write(str(d)) i += 1 if i == 40: print(""); i = 0
Maintain the same structure and functionality when rewriting this code in Python.
using System; using System.Numerics; namespace PiCalc { internal class Program { private readonly BigInteger FOUR = new BigInteger(4); private readonly BigInteger SEVEN = new BigInteger(7); private readonly BigInteger TEN = new BigInteger(10); private readonly BigInteger THREE = new BigInteger(3); private readonly BigInteger TWO = new BigInteger(2); private BigInteger k = BigInteger.One; private BigInteger l = new BigInteger(3); private BigInteger n = new BigInteger(3); private BigInteger q = BigInteger.One; private BigInteger r = BigInteger.Zero; private BigInteger t = BigInteger.One; public void CalcPiDigits() { BigInteger nn, nr; bool first = true; while (true) { if ((FOUR*q + r - t).CompareTo(n*t) == -1) { Console.Write(n); if (first) { Console.Write("."); first = false; } nr = TEN*(r - (n*t)); n = TEN*(THREE*q + r)/t - (TEN*n); q *= TEN; r = nr; } else { nr = (TWO*q + r)*l; nn = (q*(SEVEN*k) + TWO + r*l)/(t*l); q *= k; t *= l; l += TWO; k += BigInteger.One; n = nn; r = nr; } } } private static void Main(string[] args) { new Program().CalcPiDigits(); } } }
def calcPi(): q, r, t, k, n, l = 1, 0, 1, 1, 3, 3 while True: if 4*q+r-t < n*t: yield n nr = 10*(r-n*t) n = ((10*(3*q+r))//t)-10*n q *= 10 r = nr else: nr = (2*q+r)*l nn = (q*(7*k)+2+(r*l))//(t*l) q *= k t *= l l += 2 k += 1 n = nn r = nr import sys pi_digits = calcPi() i = 0 for d in pi_digits: sys.stdout.write(str(d)) i += 1 if i == 40: print(""); i = 0
Rewrite the snippet below in Python so it works the same as the original C# code.
using System; static class YCombinator<T, TResult> { private delegate Func<T, TResult> RecursiveFunc(RecursiveFunc r); public static Func<Func<Func<T, TResult>, Func<T, TResult>>, Func<T, TResult>> Fix { get; } = f => ((RecursiveFunc)(g => f(x => g(g)(x))))(g => f(x => g(g)(x))); } static class Program { static void Main() { var fac = YCombinator<int, int>.Fix(f => x => x < 2 ? 1 : x * f(x - 1)); var fib = YCombinator<int, int>.Fix(f => x => x < 2 ? x : f(x - 1) + f(x - 2)); Console.WriteLine(fac(10)); Console.WriteLine(fib(10)); } }
>>> Y = lambda f: (lambda x: x(x))(lambda y: f(lambda *args: y(y)(*args))) >>> fac = lambda f: lambda n: (1 if n<2 else n*f(n-1)) >>> [ Y(fac)(i) for i in range(10) ] [1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880] >>> fib = lambda f: lambda n: 0 if n == 0 else (1 if n == 1 else f(n-1) + f(n-2)) >>> [ Y(fib)(i) for i in range(10) ] [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
Convert this C# snippet to Python and keep its semantics consistent.
using System.Linq; class Program { static void Main() { int a, b, c, d, e, f, g; int[] h = new int[g = 1000]; for (a = 0, b = 1, c = 2; c < g; a = b, b = c++) for (d = a, e = b - d, f = h[b]; e <= b; e++) if (f == h[d--]) { h[c] = e; break; } void sho(int i) { System.Console.WriteLine(string.Join(" ", h.Skip(i).Take(10))); } sho(0); sho(990); } }
def van_eck(): n, seen, val = 0, {}, 0 while True: yield val last = {val: n} val = n - seen.get(val, n) seen.update(last) n += 1 if __name__ == '__main__': print("Van Eck: first 10 terms: ", list(islice(van_eck(), 10))) print("Van Eck: terms 991 - 1000:", list(islice(van_eck(), 1000))[-10:])
Change the following C# code into Python without altering its purpose.
using System.Linq; class Program { static void Main() { int a, b, c, d, e, f, g; int[] h = new int[g = 1000]; for (a = 0, b = 1, c = 2; c < g; a = b, b = c++) for (d = a, e = b - d, f = h[b]; e <= b; e++) if (f == h[d--]) { h[c] = e; break; } void sho(int i) { System.Console.WriteLine(string.Join(" ", h.Skip(i).Take(10))); } sho(0); sho(990); } }
def van_eck(): n, seen, val = 0, {}, 0 while True: yield val last = {val: n} val = n - seen.get(val, n) seen.update(last) n += 1 if __name__ == '__main__': print("Van Eck: first 10 terms: ", list(islice(van_eck(), 10))) print("Van Eck: terms 991 - 1000:", list(islice(van_eck(), 1000))[-10:])
Write a version of this C# function in Python with identical behavior.
using System; class Program { static void Main(string[] args) { for (int i = 1; i <= 10; i++) { Console.Write(i); if (i % 5 == 0) { Console.WriteLine(); continue; } Console.Write(", "); } } }
for i in range(1, 11): if i % 5 == 0: print(i) continue print(i, end=', ')
Write the same code in Python as shown below in C#.
using System; public class GeneralFizzBuzz { public static void Main() { int i; int j; int k; int limit; string iString; string jString; string kString; Console.WriteLine("First integer:"); i = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("First string:"); iString = Console.ReadLine(); Console.WriteLine("Second integer:"); j = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Second string:"); jString = Console.ReadLine(); Console.WriteLine("Third integer:"); k = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Third string:"); kString = Console.ReadLine(); Console.WriteLine("Limit (inclusive):"); limit = Convert.ToInt32(Console.ReadLine()); for(int n = 1; n<= limit; n++) { bool flag = true; if(n%i == 0) { Console.Write(iString); flag = false; } if(n%j == 0) { Console.Write(jString); flag = false; } if(n%k == 0) { Console.Write(kString); flag = false; } if(flag) Console.Write(n); Console.WriteLine(); } } }
def genfizzbuzz(factorwords, numbers): factorwords.sort(key=lambda factor_and_word: factor_and_word[0]) lines = [] for num in numbers: words = ''.join(word for factor, word in factorwords if (num % factor) == 0) lines.append(words if words else str(num)) return '\n'.join(lines) if __name__ == '__main__': print(genfizzbuzz([(5, 'Buzz'), (3, 'Fizz'), (7, 'Baxx')], range(1, 21)))
Transform the following C# implementation into Python, maintaining the same output and logic.
using System; using System.Linq; using System.Threading; using System.Threading.Tasks; namespace Rosetta.CheckPointSync; public class Program { public async Task Main() { RobotBuilder robotBuilder = new RobotBuilder(); Task work = robotBuilder.BuildRobots( "Optimus Prime", "R. Giskard Reventlov", "Data", "Marvin", "Bender", "Number Six", "C3-PO", "Dolores"); await work; } public class RobotBuilder { static readonly string[] parts = { "Head", "Torso", "Left arm", "Right arm", "Left leg", "Right leg" }; static readonly Random rng = new Random(); static readonly object key = new object(); public Task BuildRobots(params string[] robots) { int r = 0; Barrier checkpoint = new Barrier(parts.Length, b => { Console.WriteLine($"{robots[r]} assembled. Hello, {robots[r]}!"); Console.WriteLine(); r++; }); var tasks = parts.Select(part => BuildPart(checkpoint, part, robots)).ToArray(); return Task.WhenAll(tasks); } private static int GetTime() { lock (key) { return rng.Next(100, 1000); } } private async Task BuildPart(Barrier barrier, string part, string[] robots) { foreach (var robot in robots) { int time = GetTime(); Console.WriteLine($"Constructing {part} for {robot}. This will take {time}ms."); await Task.Delay(time); Console.WriteLine($"{part} for {robot} finished."); barrier.SignalAndWait(); } } } }
import threading import time import random def worker(workernum, barrier): sleeptime = random.random() print('Starting worker '+str(workernum)+" task 1, sleeptime="+str(sleeptime)) time.sleep(sleeptime) print('Exiting worker'+str(workernum)) barrier.wait() sleeptime = random.random() print('Starting worker '+str(workernum)+" task 2, sleeptime="+str(sleeptime)) time.sleep(sleeptime) print('Exiting worker'+str(workernum)) barrier = threading.Barrier(3) w1 = threading.Thread(target=worker, args=((1,barrier))) w2 = threading.Thread(target=worker, args=((2,barrier))) w3 = threading.Thread(target=worker, args=((3,barrier))) w1.start() w2.start() w3.start()
Maintain the same structure and functionality when rewriting this code in Python.
namespace Vlq { using System; using System.Collections.Generic; using System.Linq; public static class VarLenQuantity { public static ulong ToVlq(ulong integer) { var array = new byte[8]; var buffer = ToVlqCollection(integer) .SkipWhile(b => b == 0) .Reverse() .ToArray(); Array.Copy(buffer, array, buffer.Length); return BitConverter.ToUInt64(array, 0); } public static ulong FromVlq(ulong integer) { var collection = BitConverter.GetBytes(integer).Reverse(); return FromVlqCollection(collection); } public static IEnumerable<byte> ToVlqCollection(ulong integer) { if (integer > Math.Pow(2, 56)) throw new OverflowException("Integer exceeds max value."); var index = 7; var significantBitReached = false; var mask = 0x7fUL << (index * 7); while (index >= 0) { var buffer = (mask & integer); if (buffer > 0 || significantBitReached) { significantBitReached = true; buffer >>= index * 7; if (index > 0) buffer |= 0x80; yield return (byte)buffer; } mask >>= 7; index--; } } public static ulong FromVlqCollection(IEnumerable<byte> vlq) { ulong integer = 0; var significantBitReached = false; using (var enumerator = vlq.GetEnumerator()) { int index = 0; while (enumerator.MoveNext()) { var buffer = enumerator.Current; if (buffer > 0 || significantBitReached) { significantBitReached = true; integer <<= 7; integer |= (buffer & 0x7fUL); } if (++index == 8 || (significantBitReached && (buffer & 0x80) != 0x80)) break; } } return integer; } public static void Main() { var integers = new ulong[] { 0x7fUL << 7 * 7, 0x80, 0x2000, 0x3FFF, 0x4000, 0x200000, 0x1fffff }; foreach (var original in integers) { Console.WriteLine("Original: 0x{0:X}", original); var seq = ToVlqCollection(original); Console.WriteLine("Sequence: 0x{0}", seq.Select(b => b.ToString("X2")).Aggregate(string.Concat)); var decoded = FromVlqCollection(seq); Console.WriteLine("Decoded: 0x{0:X}", decoded); var encoded = ToVlq(original); Console.WriteLine("Encoded: 0x{0:X}", encoded); decoded = FromVlq(encoded); Console.WriteLine("Decoded: 0x{0:X}", decoded); Console.WriteLine(); } Console.WriteLine("Press any key to continue..."); Console.ReadKey(); } } }
def tobits(n, _group=8, _sep='_', _pad=False): 'Express n as binary bits with separator' bits = '{0:b}'.format(n)[::-1] if _pad: bits = '{0:0{1}b}'.format(n, ((_group+len(bits)-1)//_group)*_group)[::-1] answer = _sep.join(bits[i:i+_group] for i in range(0, len(bits), _group))[::-1] answer = '0'*(len(_sep)-1) + answer else: answer = _sep.join(bits[i:i+_group] for i in range(0, len(bits), _group))[::-1] return answer def tovlq(n): return tobits(n, _group=7, _sep='1_', _pad=True) def toint(vlq): return int(''.join(vlq.split('_1')), 2) def vlqsend(vlq): for i, byte in enumerate(vlq.split('_')[::-1]): print('Sent byte {0:3}: {1:
Change the programming language of this snippet from C# to Python without modifying what it does.
using System; namespace StringCase { class Program { public static void Main() { String input = scope .("alphaBETA"); input.ToUpper(); Console.WriteLine(input); input.ToLower(); Console.WriteLine(input); } } }
s = "alphaBETA" print s.upper() print s.lower() print s.swapcase() print "fOo bAR".capitalize() print "fOo bAR".title() import string print string.capwords("fOo bAR")
Preserve the algorithm and functionality while converting the code from C# to Python.
using System.Text; using System.Security.Cryptography; byte[] data = Encoding.ASCII.GetBytes("The quick brown fox jumped over the lazy dog's back"); byte[] hash = MD5.Create().ComputeHash(data); Console.WriteLine(BitConverter.ToString(hash).Replace("-", "").ToLower());
>>> import hashlib >>> >>> tests = ( (b"", 'd41d8cd98f00b204e9800998ecf8427e'), (b"a", '0cc175b9c0f1b6a831c399e269772661'), (b"abc", '900150983cd24fb0d6963f7d28e17f72'), (b"message digest", 'f96b697d7cb7938d525a2f31aaf161d0'), (b"abcdefghijklmnopqrstuvwxyz", 'c3fcd3d76192e4007dfb496cca67e13b'), (b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", 'd174ab98d277d9f5a5611c2c9f419d9f'), (b"12345678901234567890123456789012345678901234567890123456789012345678901234567890", '57edf4a22be3c955ac49da2e2107b67a') ) >>> for text, golden in tests: assert hashlib.md5(text).hexdigest() == golden >>>
Transform the following C# implementation into Python, maintaining the same output and logic.
class Program { static void Main(string[] args) { CultureInfo ci=CultureInfo.CreateSpecificCulture("en-US"); string dateString = "March 7 2009 7:30pm EST"; string format = "MMMM d yyyy h:mmtt z"; DateTime myDateTime = DateTime.ParseExact(dateString.Replace("EST","+6"),format,ci) ; DateTime newDateTime = myDateTime.AddHours(12).AddDays(1) ; Console.WriteLine(newDateTime.ToString(format).Replace("-5","EST")); Console.ReadLine(); } }
import datetime def mt(): datime1="March 7 2009 7:30pm EST" formatting = "%B %d %Y %I:%M%p " datime2 = datime1[:-3] tdelta = datetime.timedelta(hours=12) s3 = datetime.datetime.strptime(datime2, formatting) datime2 = s3+tdelta print datime2.strftime("%B %d %Y %I:%M%p %Z") + datime1[-3:] mt()
Produce a functionally identical Python code for the snippet given in C#.
using System; using System.Collections.Generic; using System.Linq; using System.Threading; class Program { static void ThreadStart(object item) { Thread.Sleep(1000 * (int)item); Console.WriteLine(item); } static void SleepSort(IEnumerable<int> items) { foreach (var item in items) { new Thread(ThreadStart).Start(item); } } static void Main(string[] arguments) { SleepSort(arguments.Select(int.Parse)); } }
from time import sleep from threading import Timer def sleepsort(values): sleepsort.result = [] def add1(x): sleepsort.result.append(x) mx = values[0] for v in values: if mx < v: mx = v Timer(v, add1, [v]).start() sleep(mx+1) return sleepsort.result if __name__ == '__main__': x = [3,2,4,7,3,6,9,1] if sleepsort(x) == sorted(x): print('sleep sort worked for:',x) else: print('sleep sort FAILED for:',x)
Convert this C# block to Python, preserving its control flow and logic.
using System; class Program { static void Main(string[] args) { int[,] a = new int[10, 10]; Random r = new Random(); for (int i = 0; i < 10; i++) { for (int j = 0; j < 10; j++) { a[i, j] = r.Next(0, 21) + 1; } } for (int i = 0; i < 10; i++) { for (int j = 0; j < 10; j++) { Console.Write(" {0}", a[i, j]); if (a[i, j] == 20) { goto Done; } } Console.WriteLine(); } Done: Console.WriteLine(); } }
from random import randint def do_scan(mat): for row in mat: for item in row: print item, if item == 20: print return print print mat = [[randint(1, 20) for x in xrange(10)] for y in xrange(10)] do_scan(mat)
Please provide an equivalent version of this C# code in Python.
int[] nums = { 1, 1, 2, 3, 4, 4 }; List<int> unique = new List<int>(); foreach (int n in nums) if (!unique.Contains(n)) unique.Add(n);
items = [1, 2, 3, 'a', 'b', 'c', 2, 3, 4, 'b', 'c', 'd'] unique = list(set(items))
Write a version of this C# function in Python with identical behavior.
int[] nums = { 1, 1, 2, 3, 4, 4 }; List<int> unique = new List<int>(); foreach (int n in nums) if (!unique.Contains(n)) unique.Add(n);
items = [1, 2, 3, 'a', 'b', 'c', 2, 3, 4, 'b', 'c', 'd'] unique = list(set(items))
Keep all operations the same but rewrite the snippet in Python.
using System; using System.Text; using System.Linq; class Program { static string lookandsay(string number) { StringBuilder result = new StringBuilder(); char repeat = number[0]; number = number.Substring(1, number.Length-1)+" "; int times = 1; foreach (char actual in number) { if (actual != repeat) { result.Append(Convert.ToString(times)+repeat); times = 1; repeat = actual; } else { times += 1; } } return result.ToString(); } static void Main(string[] args) { string num = "1"; foreach (int i in Enumerable.Range(1, 10)) { Console.WriteLine(num); num = lookandsay(num); } } }
def lookandsay(number): result = "" repeat = number[0] number = number[1:]+" " times = 1 for actual in number: if actual != repeat: result += str(times)+repeat times = 1 repeat = actual else: times += 1 return result num = "1" for i in range(10): print num num = lookandsay(num)
Convert this C# snippet to Python and keep its semantics consistent.
System.Collections.Stack stack = new System.Collections.Stack(); stack.Push( obj ); bool isEmpty = stack.Count == 0; object top = stack.Peek(); top = stack.Pop(); System.Collections.Generic.Stack<Foo> stack = new System.Collections.Generic.Stack<Foo>(); stack.Push(new Foo()); bool isEmpty = stack.Count == 0; Foo top = stack.Peek(); top = stack.Pop();
from collections import deque stack = deque() stack.append(value) value = stack.pop() not stack
Convert this C# block to Python, preserving its control flow and logic.
using static System.Console; using static System.Linq.Enumerable; public class Program { static void Main() { for (int i = 1; i <= 25; i++) { int t = Totient(i); WriteLine(i + "\t" + t + (t == i - 1 ? "\tprime" : "")); } WriteLine(); for (int i = 100; i <= 100_000; i *= 10) { WriteLine($"{Range(1, i).Count(x => Totient(x) + 1 == x):n0} primes below {i:n0}"); } } static int Totient(int n) { if (n < 3) return 1; if (n == 3) return 2; int totient = n; if ((n & 1) == 0) { totient >>= 1; while (((n >>= 1) & 1) == 0) ; } for (int i = 3; i * i <= n; i += 2) { if (n % i == 0) { totient -= totient / i; while ((n /= i) % i == 0) ; } } if (n > 1) totient -= totient / n; return totient; } }
from math import gcd def φ(n): return sum(1 for k in range(1, n + 1) if gcd(n, k) == 1) if __name__ == '__main__': def is_prime(n): return φ(n) == n - 1 for n in range(1, 26): print(f" φ({n}) == {φ(n)}{', is prime' if is_prime(n) else ''}") count = 0 for n in range(1, 10_000 + 1): count += is_prime(n) if n in {100, 1000, 10_000}: print(f"Primes up to {n}: {count}")
Translate the given C# code snippet into Python without altering its behavior.
using static System.Console; using static System.Linq.Enumerable; public class Program { static void Main() { for (int i = 1; i <= 25; i++) { int t = Totient(i); WriteLine(i + "\t" + t + (t == i - 1 ? "\tprime" : "")); } WriteLine(); for (int i = 100; i <= 100_000; i *= 10) { WriteLine($"{Range(1, i).Count(x => Totient(x) + 1 == x):n0} primes below {i:n0}"); } } static int Totient(int n) { if (n < 3) return 1; if (n == 3) return 2; int totient = n; if ((n & 1) == 0) { totient >>= 1; while (((n >>= 1) & 1) == 0) ; } for (int i = 3; i * i <= n; i += 2) { if (n % i == 0) { totient -= totient / i; while ((n /= i) % i == 0) ; } } if (n > 1) totient -= totient / n; return totient; } }
from math import gcd def φ(n): return sum(1 for k in range(1, n + 1) if gcd(n, k) == 1) if __name__ == '__main__': def is_prime(n): return φ(n) == n - 1 for n in range(1, 26): print(f" φ({n}) == {φ(n)}{', is prime' if is_prime(n) else ''}") count = 0 for n in range(1, 10_000 + 1): count += is_prime(n) if n in {100, 1000, 10_000}: print(f"Primes up to {n}: {count}")
Translate the given C# code snippet into Python without altering its behavior.
if (condition) { } if (condition) { } else if (condition2) { } else { }
if x == 0: foo() elif x == 1: bar() elif x == 2: baz() else: qux() match x: 0 => foo() 1 => bar() 2 => baz() _ => qux() (a) ? b : c
Produce a language-to-language conversion: from C# to Python, same semantics.
using System; using System.Collections.Generic; namespace RosettaCode { class SortCustomComparator { public void CustomSort() { String[] items = { "Here", "are", "some", "sample", "strings", "to", "be", "sorted" }; List<String> list = new List<string>(items); DisplayList("Unsorted", list); list.Sort(CustomCompare); DisplayList("Descending Length", list); list.Sort(); DisplayList("Ascending order", list); } public int CustomCompare(String x, String y) { int result = -x.Length.CompareTo(y.Length); if (result == 0) { result = x.ToLower().CompareTo(y.ToLower()); } return result; } public void DisplayList(String header, List<String> theList) { Console.WriteLine(header); Console.WriteLine("".PadLeft(header.Length, '*')); foreach (String str in theList) { Console.WriteLine(str); } Console.WriteLine(); } } }
strings = "here are Some sample strings to be sorted".split() def mykey(x): return -len(x), x.upper() print sorted(strings, key=mykey)
Produce a language-to-language conversion: from C# to Python, same semantics.
using System; using System.Collections.Generic; namespace RosettaCode { class SortCustomComparator { public void CustomSort() { String[] items = { "Here", "are", "some", "sample", "strings", "to", "be", "sorted" }; List<String> list = new List<string>(items); DisplayList("Unsorted", list); list.Sort(CustomCompare); DisplayList("Descending Length", list); list.Sort(); DisplayList("Ascending order", list); } public int CustomCompare(String x, String y) { int result = -x.Length.CompareTo(y.Length); if (result == 0) { result = x.ToLower().CompareTo(y.ToLower()); } return result; } public void DisplayList(String header, List<String> theList) { Console.WriteLine(header); Console.WriteLine("".PadLeft(header.Length, '*')); foreach (String str in theList) { Console.WriteLine(str); } Console.WriteLine(); } } }
strings = "here are Some sample strings to be sorted".split() def mykey(x): return -len(x), x.upper() print sorted(strings, key=mykey)
Write the same code in Python as shown below in C#.
using System; using System.Drawing; using System.Windows.Forms; namespace BasicAnimation { class BasicAnimationForm : Form { bool isReverseDirection; Label textLabel; Timer timer; internal BasicAnimationForm() { this.Size = new Size(150, 75); this.Text = "Basic Animation"; textLabel = new Label(); textLabel.Text = "Hello World! "; textLabel.Location = new Point(3,3); textLabel.AutoSize = true; textLabel.Click += new EventHandler(textLabel_OnClick); this.Controls.Add(textLabel); timer = new Timer(); timer.Interval = 500; timer.Tick += new EventHandler(timer_OnTick); timer.Enabled = true; isReverseDirection = false; } private void timer_OnTick(object sender, EventArgs e) { string oldText = textLabel.Text, newText; if(isReverseDirection) newText = oldText.Substring(1, oldText.Length - 1) + oldText.Substring(0, 1); else newText = oldText.Substring(oldText.Length - 1, 1) + oldText.Substring(0, oldText.Length - 1); textLabel.Text = newText; } private void textLabel_OnClick(object sender, EventArgs e) { isReverseDirection = !isReverseDirection; } } class Program { static void Main() { Application.Run(new BasicAnimationForm()); } } }
txt = "Hello, world! " left = True def draw(): global txt background(128) text(txt, 10, height / 2) if frameCount % 10 == 0: if (left): txt = rotate(txt, 1) else: txt = rotate(txt, -1) println(txt) def mouseReleased(): global left left = not left def rotate(text, startIdx): rotated = text[startIdx:] + text[:startIdx] return rotated
Ensure the translated Python code behaves exactly like the original C# snippet.
using System; namespace RadixSort { class Program { static void Sort(int[] old) { int i, j; int[] tmp = new int[old.Length]; for (int shift = 31; shift > -1; --shift) { j = 0; for (i = 0; i < old.Length; ++i) { bool move = (old[i] << shift) >= 0; if (shift == 0 ? !move : move) old[i-j] = old[i]; else tmp[j++] = old[i]; } Array.Copy(tmp, 0, old, old.Length-j, j); } } static void Main(string[] args) { int[] old = new int[] { 2, 5, 1, -3, 4 }; Console.WriteLine(string.Join(", ", old)); Sort(old); Console.WriteLine(string.Join(", ", old)); Console.Read(); } } }
from math import log def getDigit(num, base, digit_num): return (num // base ** digit_num) % base def makeBlanks(size): return [ [] for i in range(size) ] def split(a_list, base, digit_num): buckets = makeBlanks(base) for num in a_list: buckets[getDigit(num, base, digit_num)].append(num) return buckets def merge(a_list): new_list = [] for sublist in a_list: new_list.extend(sublist) return new_list def maxAbs(a_list): return max(abs(num) for num in a_list) def split_by_sign(a_list): buckets = [[], []] for num in a_list: if num < 0: buckets[0].append(num) else: buckets[1].append(num) return buckets def radixSort(a_list, base): passes = int(round(log(maxAbs(a_list), base)) + 1) new_list = list(a_list) for digit_num in range(passes): new_list = merge(split(new_list, base, digit_num)) return merge(split_by_sign(new_list))
Change the programming language of this snippet from C# to Python without modifying what it does.
using System.Linq; static class Program { static void Main() { var ts = from a in Enumerable.Range(1, 20) from b in Enumerable.Range(a, 21 - a) from c in Enumerable.Range(b, 21 - b) where a * a + b * b == c * c select new { a, b, c }; foreach (var t in ts) System.Console.WriteLine("{0}, {1}, {2}", t.a, t.b, t.c); } }
[(x,y,z) for x in xrange(1,n+1) for y in xrange(x,n+1) for z in xrange(y,n+1) if x**2 + y**2 == z**2]
Transform the following C# implementation into Python, maintaining the same output and logic.
class SelectionSort<T> where T : IComparable { public T[] Sort(T[] list) { int k; T temp; for (int i = 0; i < list.Length; i++) { k = i; for (int j=i + 1; j < list.Length; j++) { if (list[j].CompareTo(list[k]) < 0) { k = j; } } temp = list[i]; list[i] = list[k]; list[k] = temp; } return list; } }
def selection_sort(lst): for i, e in enumerate(lst): mn = min(range(i,len(lst)), key=lst.__getitem__) lst[i], lst[mn] = lst[mn], e return lst
Keep all operations the same but rewrite the snippet in Python.
int[] intArray = { 1, 2, 3, 4, 5 }; int[] squares1 = intArray.Select(x => x * x).ToArray(); int[] squares2 = (from x in intArray select x * x).ToArray(); foreach (var i in intArray) Console.WriteLine(i * i);
def square(n): return n * n numbers = [1, 3, 5, 7] squares1 = [square(n) for n in numbers] squares2a = map(square, numbers) squares2b = map(lambda x: x*x, numbers) squares3 = [n * n for n in numbers] isquares1 = (n * n for n in numbers) import itertools isquares2 = itertools.imap(square, numbers)
Transform the following C# implementation into Python, maintaining the same output and logic.
public sealed class Singleton1 { private static Singleton1 instance; private static readonly object lockObj = new object(); public static Singleton1 Instance { get { lock(lockObj) { if (instance == null) { instance = new Singleton1(); } } return instance; } } }
>>> class Borg(object): __state = {} def __init__(self): self.__dict__ = self.__state >>> b1 = Borg() >>> b2 = Borg() >>> b1 is b2 False >>> b1.datum = range(5) >>> b1.datum [0, 1, 2, 3, 4] >>> b2.datum [0, 1, 2, 3, 4] >>> b1.datum is b2.datum True >>>
Can you help me rewrite this code in Python instead of C#, keeping it the same logically?
using System; namespace SafeAddition { class Program { static float NextUp(float d) { if (d == 0.0) return float.Epsilon; if (float.IsNaN(d) || float.IsNegativeInfinity(d) || float.IsPositiveInfinity(d)) return d; byte[] bytes = BitConverter.GetBytes(d); int dl = BitConverter.ToInt32(bytes, 0); dl++; bytes = BitConverter.GetBytes(dl); return BitConverter.ToSingle(bytes, 0); } static float NextDown(float d) { if (d == 0.0) return -float.Epsilon; if (float.IsNaN(d) || float.IsNegativeInfinity(d) || float.IsPositiveInfinity(d)) return d; byte[] bytes = BitConverter.GetBytes(d); int dl = BitConverter.ToInt32(bytes, 0); dl--; bytes = BitConverter.GetBytes(dl); return BitConverter.ToSingle(bytes, 0); } static Tuple<float, float> SafeAdd(float a, float b) { return new Tuple<float, float>(NextDown(a + b), NextUp(a + b)); } static void Main(string[] args) { float a = 1.20f; float b = 0.03f; Console.WriteLine("({0} + {1}) is in the range {2}", a, b, SafeAdd(a, b)); } } }
>>> sum([.1, .1, .1, .1, .1, .1, .1, .1, .1, .1]) 0.9999999999999999 >>> from math import fsum >>> fsum([.1, .1, .1, .1, .1, .1, .1, .1, .1, .1]) 1.0
Keep all operations the same but rewrite the snippet in Python.
for (int i = 10; i >= 0; i--) { Console.WriteLine(i); }
for i in xrange(10, -1, -1): print i
Rewrite this program in Python while keeping its functionality equivalent to the C# version.
System.IO.File.WriteAllText("filename.txt", "This file contains a string.");
with open(filename, 'w') as f: f.write(data)
Transform the following C# implementation into Python, maintaining the same output and logic.
using System; class Program { static void Main(string[] args) { for (int i = 0; i < 5; i++) { for (int j = 0; j <= i; j++) { Console.Write("*"); } Console.WriteLine(); } } }
for i in 1..5: for j in 1..i: stdout.write("*") echo("")