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Rewrite this program in Java while keeping its functionality equivalent to the Go version.
package main import "fmt" var a = []int{170, 45, 75, -90, -802, 24, 2, 66} func main() { fmt.Println("before:", a) stoogesort(a) fmt.Println("after: ", a) fmt.Println("nyuk nyuk nyuk") } func stoogesort(a []int) { last := len(a) - 1 if a[last] < a[0] { a[0], a[last] = a[last], a[0] } if last > 1 { t := len(a) / 3 stoogesort(a[:len(a)-t]) stoogesort(a[t:]) stoogesort(a[:len(a)-t]) } }
import java.util.Arrays; public class Stooge { public static void main(String[] args) { int[] nums = {1, 4, 5, 3, -6, 3, 7, 10, -2, -5}; stoogeSort(nums); System.out.println(Arrays.toString(nums)); } public static void stoogeSort(int[] L) { stoogeSort(L, 0, L.length - 1); } public static void stoogeSort(int[] L, int i, int j) { if (L[j] < L[i]) { int tmp = L[i]; L[i] = L[j]; L[j] = tmp; } if (j - i > 1) { int t = (j - i + 1) / 3; stoogeSort(L, i, j - t); stoogeSort(L, i + t, j); stoogeSort(L, i, j - t); } } }
Port the following code from Go to Java with equivalent syntax and logic.
package main import ( "fmt" "math/rand" "time" ) const boxW = 41 const boxH = 37 const pinsBaseW = 19 const nMaxBalls = 55 const centerH = pinsBaseW + (boxW-pinsBaseW*2+1)/2 - 1 const ( empty = ' ' ball = 'o' wall = '|' corner = '+' floor = '-' pin = '.' ) type Ball struct{ x, y int } func newBall(x, y int) *Ball { if box[y][x] != empty { panic("Tried to create a new ball in a non-empty cell. Program terminated.") } b := Ball{x, y} box[y][x] = ball return &b } func (b *Ball) doStep() { if b.y <= 0 { return } cell := box[b.y-1][b.x] switch cell { case empty: box[b.y][b.x] = empty b.y-- box[b.y][b.x] = ball case pin: box[b.y][b.x] = empty b.y-- if box[b.y][b.x-1] == empty && box[b.y][b.x+1] == empty { b.x += rand.Intn(2)*2 - 1 box[b.y][b.x] = ball return } else if box[b.y][b.x-1] == empty { b.x++ } else { b.x-- } box[b.y][b.x] = ball default: } } type Cell = byte var box [boxH][boxW]Cell func initializeBox() { box[0][0] = corner box[0][boxW-1] = corner for i := 1; i < boxW-1; i++ { box[0][i] = floor } for i := 0; i < boxW; i++ { box[boxH-1][i] = box[0][i] } for r := 1; r < boxH-1; r++ { box[r][0] = wall box[r][boxW-1] = wall } for i := 1; i < boxH-1; i++ { for j := 1; j < boxW-1; j++ { box[i][j] = empty } } for nPins := 1; nPins <= pinsBaseW; nPins++ { for p := 0; p < nPins; p++ { box[boxH-2-nPins][centerH+1-nPins+p*2] = pin } } } func drawBox() { for r := boxH - 1; r >= 0; r-- { for c := 0; c < boxW; c++ { fmt.Printf("%c", box[r][c]) } fmt.Println() } } func main() { rand.Seed(time.Now().UnixNano()) initializeBox() var balls []*Ball for i := 0; i < nMaxBalls+boxH; i++ { fmt.Println("\nStep", i, ":") if i < nMaxBalls { balls = append(balls, newBall(centerH, boxH-2)) } drawBox() for _, b := range balls { b.doStep() } } }
import java.util.Random; import java.util.List; import java.util.ArrayList; public class GaltonBox { public static void main( final String[] args ) { new GaltonBox( 8, 200 ).run(); } private final int m_pinRows; private final int m_startRow; private final Position[] m_balls; private final Random m_random = new Random(); public GaltonBox( final int pinRows, final int ballCount ) { m_pinRows = pinRows; m_startRow = pinRows + 1; m_balls = new Position[ ballCount ]; for ( int ball = 0; ball < ballCount; ball++ ) m_balls[ ball ] = new Position( m_startRow, 0, 'o' ); } private static class Position { int m_row; int m_col; char m_char; Position( final int row, final int col, final char ch ) { m_row = row; m_col = col; m_char = ch; } } public void run() { for ( int ballsInPlay = m_balls.length; ballsInPlay > 0; ) { ballsInPlay = dropBalls(); print(); } } private int dropBalls() { int ballsInPlay = 0; int ballToStart = -1; for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == m_startRow ) ballToStart = ball; for ( int ball = 0; ball < m_balls.length; ball++ ) if ( ball == ballToStart ) { m_balls[ ball ].m_row = m_pinRows; ballsInPlay++; } else if ( m_balls[ ball ].m_row > 0 && m_balls[ ball ].m_row != m_startRow ) { m_balls[ ball ].m_row -= 1; m_balls[ ball ].m_col += m_random.nextInt( 2 ); if ( 0 != m_balls[ ball ].m_row ) ballsInPlay++; } return ballsInPlay; } private void print() { for ( int row = m_startRow; row --> 1; ) { for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == row ) printBall( m_balls[ ball ] ); System.out.println(); printPins( row ); } printCollectors(); System.out.println(); } private static void printBall( final Position pos ) { for ( int col = pos.m_row + 1; col --> 0; ) System.out.print( ' ' ); for ( int col = 0; col < pos.m_col; col++ ) System.out.print( " " ); System.out.print( pos.m_char ); } private void printPins( final int row ) { for ( int col = row + 1; col --> 0; ) System.out.print( ' ' ); for ( int col = m_startRow - row; col --> 0; ) System.out.print( ". " ); System.out.println(); } private void printCollectors() { final List<List<Position>> collectors = new ArrayList<List<Position>>(); for ( int col = 0; col < m_startRow; col++ ) { final List<Position> collector = new ArrayList<Position>(); collectors.add( collector ); for ( int ball = 0; ball < m_balls.length; ball++ ) if ( m_balls[ ball ].m_row == 0 && m_balls[ ball ].m_col == col ) collector.add( m_balls[ ball ] ); } for ( int row = 0, rows = longest( collectors ); row < rows; row++ ) { for ( int col = 0; col < m_startRow; col++ ) { final List<Position> collector = collectors.get( col ); final int pos = row + collector.size() - rows; System.out.print( '|' ); if ( pos >= 0 ) System.out.print( collector.get( pos ).m_char ); else System.out.print( ' ' ); } System.out.println( '|' ); } } private static final int longest( final List<List<Position>> collectors ) { int result = 0; for ( final List<Position> collector : collectors ) result = Math.max( collector.size(), result ); return result; } }
Port the provided Go code into Java while preserving the original functionality.
package main import "fmt" func circleSort(a []int, lo, hi, swaps int) int { if lo == hi { return swaps } high, low := hi, lo mid := (hi - lo) / 2 for lo < hi { if a[lo] > a[hi] { a[lo], a[hi] = a[hi], a[lo] swaps++ } lo++ hi-- } if lo == hi { if a[lo] > a[hi+1] { a[lo], a[hi+1] = a[hi+1], a[lo] swaps++ } } swaps = circleSort(a, low, low+mid, swaps) swaps = circleSort(a, low+mid+1, high, swaps) return swaps } func main() { aa := [][]int{ {6, 7, 8, 9, 2, 5, 3, 4, 1}, {2, 14, 4, 6, 8, 1, 3, 5, 7, 11, 0, 13, 12, -1}, } for _, a := range aa { fmt.Printf("Original: %v\n", a) for circleSort(a, 0, len(a)-1, 0) != 0 { } fmt.Printf("Sorted  : %v\n\n", a) } }
import java.util.Arrays; public class CircleSort { public static void main(String[] args) { circleSort(new int[]{2, 14, 4, 6, 8, 1, 3, 5, 7, 11, 0, 13, 12, -1}); } public static void circleSort(int[] arr) { if (arr.length > 0) do { System.out.println(Arrays.toString(arr)); } while (circleSortR(arr, 0, arr.length - 1, 0) != 0); } private static int circleSortR(int[] arr, int lo, int hi, int numSwaps) { if (lo == hi) return numSwaps; int high = hi; int low = lo; int mid = (hi - lo) / 2; while (lo < hi) { if (arr[lo] > arr[hi]) { swap(arr, lo, hi); numSwaps++; } lo++; hi--; } if (lo == hi && arr[lo] > arr[hi + 1]) { swap(arr, lo, hi + 1); numSwaps++; } numSwaps = circleSortR(arr, low, low + mid, numSwaps); numSwaps = circleSortR(arr, low + mid + 1, high, numSwaps); return numSwaps; } private static void swap(int[] arr, int idx1, int idx2) { int tmp = arr[idx1]; arr[idx1] = arr[idx2]; arr[idx2] = tmp; } }
Please provide an equivalent version of this Go code in Java.
package main import "fmt" type matrix [][]int func (m1 matrix) kroneckerProduct(m2 matrix) matrix { m := len(m1) n := len(m1[0]) p := len(m2) q := len(m2[0]) rtn := m * p ctn := n * q r := make(matrix, rtn) for i := range r { r[i] = make([]int, ctn) } for i := 0; i < m; i++ { for j := 0; j < n; j++ { for k := 0; k < p; k++ { for l := 0; l < q; l++ { r[p*i+k][q*j+l] = m1[i][j] * m2[k][l] } } } } return r } func (m matrix) kroneckerPower(n int) matrix { pow := m for i := 1; i < n; i++ { pow = pow.kroneckerProduct(m) } return pow } func (m matrix) print(text string) { fmt.Println(text, "fractal :\n") for i := range m { for j := range m[0] { if m[i][j] == 1 { fmt.Print("*") } else { fmt.Print(" ") } } fmt.Println() } fmt.Println() } func main() { m1 := matrix{{0, 1, 0}, {1, 1, 1}, {0, 1, 0}} m1.kroneckerPower(4).print("Vivsek") m2 := matrix{{1, 1, 1}, {1, 0, 1}, {1, 1, 1}} m2.kroneckerPower(4).print("Sierpinski carpet") }
package kronecker; public class ProductFractals { public static int[][] product(final int[][] a, final int[][] b) { final int[][] c = new int[a.length*b.length][]; for (int ix = 0; ix < c.length; ix++) { final int num_cols = a[0].length*b[0].length; c[ix] = new int[num_cols]; } for (int ia = 0; ia < a.length; ia++) { for (int ja = 0; ja < a[ia].length; ja++) { for (int ib = 0; ib < b.length; ib++) { for (int jb = 0; jb < b[ib].length; jb++) { c[b.length*ia+ib][b[ib].length*ja+jb] = a[ia][ja] * b[ib][jb]; } } } } return c; } public static void show_matrix(final int[][] m, final char nz, final char z) { for (int im = 0; im < m.length; im++) { for (int jm = 0; jm < m[im].length; jm++) { System.out.print(m[im][jm] == 0 ? z : nz); } System.out.println(); } } public static int[][] power(final int[][] m, final int n) { int[][] m_pow = m; for (int ix = 1; ix < n; ix++) { m_pow = product(m, m_pow); } return m_pow; } private static void test(final int[][] m, final int n) { System.out.println("Test matrix"); show_matrix(m, '*', ' '); final int[][] m_pow = power(m, n); System.out.println("Matrix power " + n); show_matrix(m_pow, '*', ' '); } private static void test1() { final int[][] m = {{0, 1, 0}, {1, 1, 1}, {0, 1, 0}}; test(m, 4); } private static void test2() { final int[][] m = {{1, 1, 1}, {1, 0, 1}, {1, 1, 1}}; test(m, 4); } private static void test3() { final int[][] m = {{1, 0, 1}, {1, 0, 1}, {0, 1, 0}}; test(m, 4); } public static void main(final String[] args) { test1(); test2(); test3(); } }
Rewrite this program in Java while keeping its functionality equivalent to the Go version.
package config import ( "errors" "io" "fmt" "bytes" "strings" "io/ioutil" ) var ( ENONE = errors.New("Requested value does not exist") EBADTYPE = errors.New("Requested type and actual type do not match") EBADVAL = errors.New("Value and type do not match") ) type varError struct { err error n string t VarType } func (err *varError) Error() string { return fmt.Sprintf("%v: (%q, %v)", err.err, err.n, err.t) } type VarType int const ( Bool VarType = 1 + iota Array String ) func (t VarType) String() string { switch t { case Bool: return "Bool" case Array: return "Array" case String: return "String" } panic("Unknown VarType") } type confvar struct { Type VarType Val interface{} } type Config struct { m map[string]confvar } func Parse(r io.Reader) (c *Config, err error) { c = new(Config) c.m = make(map[string]confvar) buf, err := ioutil.ReadAll(r) if err != nil { return } lines := bytes.Split(buf, []byte{'\n'}) for _, line := range lines { line = bytes.TrimSpace(line) if len(line) == 0 { continue } switch line[0] { case '#', ';': continue } parts := bytes.SplitN(line, []byte{' '}, 2) nam := string(bytes.ToLower(parts[0])) if len(parts) == 1 { c.m[nam] = confvar{Bool, true} continue } if strings.Contains(string(parts[1]), ",") { tmpB := bytes.Split(parts[1], []byte{','}) for i := range tmpB { tmpB[i] = bytes.TrimSpace(tmpB[i]) } tmpS := make([]string, 0, len(tmpB)) for i := range tmpB { tmpS = append(tmpS, string(tmpB[i])) } c.m[nam] = confvar{Array, tmpS} continue } c.m[nam] = confvar{String, string(bytes.TrimSpace(parts[1]))} } return } func (c *Config) Bool(name string) (bool, error) { name = strings.ToLower(name) if _, ok := c.m[name]; !ok { return false, nil } if c.m[name].Type != Bool { return false, &varError{EBADTYPE, name, Bool} } v, ok := c.m[name].Val.(bool) if !ok { return false, &varError{EBADVAL, name, Bool} } return v, nil } func (c *Config) Array(name string) ([]string, error) { name = strings.ToLower(name) if _, ok := c.m[name]; !ok { return nil, &varError{ENONE, name, Array} } if c.m[name].Type != Array { return nil, &varError{EBADTYPE, name, Array} } v, ok := c.m[name].Val.([]string) if !ok { return nil, &varError{EBADVAL, name, Array} } return v, nil } func (c *Config) String(name string) (string, error) { name = strings.ToLower(name) if _, ok := c.m[name]; !ok { return "", &varError{ENONE, name, String} } if c.m[name].Type != String { return "", &varError{EBADTYPE, name, String} } v, ok := c.m[name].Val.(string) if !ok { return "", &varError{EBADVAL, name, String} } return v, nil }
import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.util.Arrays; import java.util.HashMap; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; public class ConfigReader { private static final Pattern LINE_PATTERN = Pattern.compile( "([^ =]+)[ =]?(.*)" ); private static final Map<String, Object> DEFAULTS = new HashMap<String, Object>() {{ put( "needspeeling", false ); put( "seedsremoved", false ); }}; public static void main( final String[] args ) { System.out.println( parseFile( args[ 0 ] ) ); } public static Map<String, Object> parseFile( final String fileName ) { final Map<String, Object> result = new HashMap<String, Object>( DEFAULTS ); BufferedReader reader = null; try { reader = new BufferedReader( new FileReader( fileName ) ); for ( String line; null != ( line = reader.readLine() ); ) { parseLine( line, result ); } } catch ( final IOException x ) { throw new RuntimeException( "Oops: " + x, x ); } finally { if ( null != reader ) try { reader.close(); } catch ( final IOException x2 ) { System.err.println( "Could not close " + fileName + " - " + x2 ); } } return result; } private static void parseLine( final String line, final Map<String, Object> map ) { if ( "".equals( line.trim() ) || line.startsWith( "#" ) || line.startsWith( ";" ) ) return; final Matcher matcher = LINE_PATTERN.matcher( line ); if ( ! matcher.matches() ) { System.err.println( "Bad config line: " + line ); return; } final String key = matcher.group( 1 ).trim().toLowerCase(); final String value = matcher.group( 2 ).trim(); if ( "".equals( value ) ) { map.put( key, true ); } else if ( -1 == value.indexOf( ',' ) ) { map.put( key, value ); } else { final String[] values = value.split( "," ); for ( int i = 0; i < values.length; i++ ) { values[ i ] = values[ i ].trim(); } map.put( key, Arrays.asList( values ) ); } } }
Keep all operations the same but rewrite the snippet in Java.
package main import ( "fmt" "sort" "strings" ) type sortable []string func (s sortable) Len() int { return len(s) } func (s sortable) Swap(i, j int) { s[i], s[j] = s[j], s[i] } func (s sortable) Less(i, j int) bool { a, b := s[i], s[j] if len(a) != len(b) { return len(a) > len(b) } return strings.ToLower(a) < strings.ToLower(b) } func main() { var s sortable = strings.Fields("To tell your name the livelong day To an admiring bog") fmt.Println(s, "(original)") sort.Sort(s) fmt.Println(s, "(sorted)") }
import java.util.Comparator; import java.util.Arrays; public class Test { public static void main(String[] args) { String[] strings = {"Here", "are", "some", "sample", "strings", "to", "be", "sorted"}; Arrays.sort(strings, new Comparator<String>() { public int compare(String s1, String s2) { int c = s2.length() - s1.length(); if (c == 0) c = s1.compareToIgnoreCase(s2); return c; } }); for (String s: strings) System.out.print(s + " "); } }
Preserve the algorithm and functionality while converting the code from Go to Java.
package main import ( "fmt" big "github.com/ncw/gmp" "strings" ) func isPrime(n int) bool { switch { case n < 2: return false case n%2 == 0: return n == 2 case n%3 == 0: return n == 3 default: d := 5 for d*d <= n { if n%d == 0 { return false } d += 2 if n%d == 0 { return false } d += 4 } return true } } func repunit(n int) *big.Int { ones := strings.Repeat("1", n) b, _ := new(big.Int).SetString(ones, 10) return b } var circs = []int{} func alreadyFound(n int) bool { for _, i := range circs { if i == n { return true } } return false } func isCircular(n int) bool { nn := n pow := 1 for nn > 0 { pow *= 10 nn /= 10 } nn = n for { nn *= 10 f := nn / pow nn += f * (1 - pow) if alreadyFound(nn) { return false } if nn == n { break } if !isPrime(nn) { return false } } return true } func main() { fmt.Println("The first 19 circular primes are:") digits := [4]int{1, 3, 7, 9} q := []int{1, 2, 3, 5, 7, 9} fq := []int{1, 2, 3, 5, 7, 9} count := 0 for { f := q[0] fd := fq[0] if isPrime(f) && isCircular(f) { circs = append(circs, f) count++ if count == 19 { break } } copy(q, q[1:]) q = q[:len(q)-1] copy(fq, fq[1:]) fq = fq[:len(fq)-1] if f == 2 || f == 5 { continue } for _, d := range digits { if d >= fd { q = append(q, f*10+d) fq = append(fq, fd) } } } fmt.Println(circs) fmt.Println("\nThe next 4 circular primes, in repunit format, are:") count = 0 var rus []string for i := 7; count < 4; i++ { if repunit(i).ProbablyPrime(10) { count++ rus = append(rus, fmt.Sprintf("R(%d)", i)) } } fmt.Println(rus) fmt.Println("\nThe following repunits are probably circular primes:") for _, i := range []int{5003, 9887, 15073, 25031, 35317, 49081} { fmt.Printf("R(%-5d) : %t\n", i, repunit(i).ProbablyPrime(10)) } }
import java.math.BigInteger; import java.util.Arrays; public class CircularPrimes { public static void main(String[] args) { System.out.println("First 19 circular primes:"); int p = 2; for (int count = 0; count < 19; ++p) { if (isCircularPrime(p)) { if (count > 0) System.out.print(", "); System.out.print(p); ++count; } } System.out.println(); System.out.println("Next 4 circular primes:"); int repunit = 1, digits = 1; for (; repunit < p; ++digits) repunit = 10 * repunit + 1; BigInteger bignum = BigInteger.valueOf(repunit); for (int count = 0; count < 4; ) { if (bignum.isProbablePrime(15)) { if (count > 0) System.out.print(", "); System.out.printf("R(%d)", digits); ++count; } ++digits; bignum = bignum.multiply(BigInteger.TEN); bignum = bignum.add(BigInteger.ONE); } System.out.println(); testRepunit(5003); testRepunit(9887); testRepunit(15073); testRepunit(25031); } private static boolean isPrime(int n) { if (n < 2) return false; if (n % 2 == 0) return n == 2; if (n % 3 == 0) return n == 3; for (int p = 5; p * p <= n; p += 4) { if (n % p == 0) return false; p += 2; if (n % p == 0) return false; } return true; } private static int cycle(int n) { int m = n, p = 1; while (m >= 10) { p *= 10; m /= 10; } return m + 10 * (n % p); } private static boolean isCircularPrime(int p) { if (!isPrime(p)) return false; int p2 = cycle(p); while (p2 != p) { if (p2 < p || !isPrime(p2)) return false; p2 = cycle(p2); } return true; } private static void testRepunit(int digits) { BigInteger repunit = repunit(digits); if (repunit.isProbablePrime(15)) System.out.printf("R(%d) is probably prime.\n", digits); else System.out.printf("R(%d) is not prime.\n", digits); } private static BigInteger repunit(int digits) { char[] ch = new char[digits]; Arrays.fill(ch, '1'); return new BigInteger(new String(ch)); } }
Produce a language-to-language conversion: from Go to Java, same semantics.
package main import ( "fmt" big "github.com/ncw/gmp" "strings" ) func isPrime(n int) bool { switch { case n < 2: return false case n%2 == 0: return n == 2 case n%3 == 0: return n == 3 default: d := 5 for d*d <= n { if n%d == 0 { return false } d += 2 if n%d == 0 { return false } d += 4 } return true } } func repunit(n int) *big.Int { ones := strings.Repeat("1", n) b, _ := new(big.Int).SetString(ones, 10) return b } var circs = []int{} func alreadyFound(n int) bool { for _, i := range circs { if i == n { return true } } return false } func isCircular(n int) bool { nn := n pow := 1 for nn > 0 { pow *= 10 nn /= 10 } nn = n for { nn *= 10 f := nn / pow nn += f * (1 - pow) if alreadyFound(nn) { return false } if nn == n { break } if !isPrime(nn) { return false } } return true } func main() { fmt.Println("The first 19 circular primes are:") digits := [4]int{1, 3, 7, 9} q := []int{1, 2, 3, 5, 7, 9} fq := []int{1, 2, 3, 5, 7, 9} count := 0 for { f := q[0] fd := fq[0] if isPrime(f) && isCircular(f) { circs = append(circs, f) count++ if count == 19 { break } } copy(q, q[1:]) q = q[:len(q)-1] copy(fq, fq[1:]) fq = fq[:len(fq)-1] if f == 2 || f == 5 { continue } for _, d := range digits { if d >= fd { q = append(q, f*10+d) fq = append(fq, fd) } } } fmt.Println(circs) fmt.Println("\nThe next 4 circular primes, in repunit format, are:") count = 0 var rus []string for i := 7; count < 4; i++ { if repunit(i).ProbablyPrime(10) { count++ rus = append(rus, fmt.Sprintf("R(%d)", i)) } } fmt.Println(rus) fmt.Println("\nThe following repunits are probably circular primes:") for _, i := range []int{5003, 9887, 15073, 25031, 35317, 49081} { fmt.Printf("R(%-5d) : %t\n", i, repunit(i).ProbablyPrime(10)) } }
import java.math.BigInteger; import java.util.Arrays; public class CircularPrimes { public static void main(String[] args) { System.out.println("First 19 circular primes:"); int p = 2; for (int count = 0; count < 19; ++p) { if (isCircularPrime(p)) { if (count > 0) System.out.print(", "); System.out.print(p); ++count; } } System.out.println(); System.out.println("Next 4 circular primes:"); int repunit = 1, digits = 1; for (; repunit < p; ++digits) repunit = 10 * repunit + 1; BigInteger bignum = BigInteger.valueOf(repunit); for (int count = 0; count < 4; ) { if (bignum.isProbablePrime(15)) { if (count > 0) System.out.print(", "); System.out.printf("R(%d)", digits); ++count; } ++digits; bignum = bignum.multiply(BigInteger.TEN); bignum = bignum.add(BigInteger.ONE); } System.out.println(); testRepunit(5003); testRepunit(9887); testRepunit(15073); testRepunit(25031); } private static boolean isPrime(int n) { if (n < 2) return false; if (n % 2 == 0) return n == 2; if (n % 3 == 0) return n == 3; for (int p = 5; p * p <= n; p += 4) { if (n % p == 0) return false; p += 2; if (n % p == 0) return false; } return true; } private static int cycle(int n) { int m = n, p = 1; while (m >= 10) { p *= 10; m /= 10; } return m + 10 * (n % p); } private static boolean isCircularPrime(int p) { if (!isPrime(p)) return false; int p2 = cycle(p); while (p2 != p) { if (p2 < p || !isPrime(p2)) return false; p2 = cycle(p2); } return true; } private static void testRepunit(int digits) { BigInteger repunit = repunit(digits); if (repunit.isProbablePrime(15)) System.out.printf("R(%d) is probably prime.\n", digits); else System.out.printf("R(%d) is not prime.\n", digits); } private static BigInteger repunit(int digits) { char[] ch = new char[digits]; Arrays.fill(ch, '1'); return new BigInteger(new String(ch)); } }
Preserve the algorithm and functionality while converting the code from Go to Java.
package main import ( "log" "time" "github.com/gdamore/tcell" ) const ( msg = "Hello World! " x0, y0 = 8, 3 shiftsPerSecond = 4 clicksToExit = 5 ) func main() { s, err := tcell.NewScreen() if err != nil { log.Fatal(err) } if err = s.Init(); err != nil { log.Fatal(err) } s.Clear() s.EnableMouse() tick := time.Tick(time.Second / shiftsPerSecond) click := make(chan bool) go func() { for { em, ok := s.PollEvent().(*tcell.EventMouse) if !ok || em.Buttons()&0xFF == tcell.ButtonNone { continue } mx, my := em.Position() if my == y0 && mx >= x0 && mx < x0+len(msg) { click <- true } } }() for inc, shift, clicks := 1, 0, 0; ; { select { case <-tick: shift = (shift + inc) % len(msg) for i, r := range msg { s.SetContent(x0+((shift+i)%len(msg)), y0, r, nil, 0) } s.Show() case <-click: clicks++ if clicks == clicksToExit { s.Fini() return } inc = len(msg) - inc } } }
import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.util.Timer; import java.util.TimerTask; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.WindowConstants; public class Rotate { private static class State { private final String text = "Hello World! "; private int startIndex = 0; private boolean rotateRight = true; } public static void main(String[] args) { State state = new State(); JLabel label = new JLabel(state.text); label.addMouseListener(new MouseAdapter() { @Override public void mouseClicked(MouseEvent event) { state.rotateRight = !state.rotateRight; } }); TimerTask task = new TimerTask() { public void run() { int delta = state.rotateRight ? 1 : -1; state.startIndex = (state.startIndex + state.text.length() + delta) % state.text.length(); label.setText(rotate(state.text, state.startIndex)); } }; Timer timer = new Timer(false); timer.schedule(task, 0, 500); JFrame rot = new JFrame(); rot.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE); rot.add(label); rot.pack(); rot.setLocationRelativeTo(null); rot.addWindowListener(new WindowAdapter() { @Override public void windowClosed(WindowEvent e) { timer.cancel(); } }); rot.setVisible(true); } private static String rotate(String text, int startIdx) { char[] rotated = new char[text.length()]; for (int i = 0; i < text.length(); i++) { rotated[i] = text.charAt((i + startIdx) % text.length()); } return String.valueOf(rotated); } }
Please provide an equivalent version of this Go code in Java.
package main import ( "bytes" "encoding/binary" "fmt" ) type word int32 const wordLen = 4 const highBit = -1 << 31 var data = []word{170, 45, 75, -90, -802, 24, 2, 66} func main() { buf := bytes.NewBuffer(nil) ds := make([][]byte, len(data)) for i, x := range data { binary.Write(buf, binary.LittleEndian, x^highBit) b := make([]byte, wordLen) buf.Read(b) ds[i] = b } bins := make([][][]byte, 256) for i := 0; i < wordLen; i++ { for _, b := range ds { bins[b[i]] = append(bins[b[i]], b) } j := 0 for k, bs := range bins { copy(ds[j:], bs) j += len(bs) bins[k] = bs[:0] } } fmt.Println("original:", data) var w word for i, b := range ds { buf.Write(b) binary.Read(buf, binary.LittleEndian, &w) data[i] = w^highBit } fmt.Println("sorted: ", data) }
public static int[] sort(int[] old) { for (int shift = Integer.SIZE - 1; shift > -1; shift--) { int[] tmp = new int[old.length]; int j = 0; for (int i = 0; i < old.length; i++) { boolean move = old[i] << shift >= 0; if (shift == 0 ? !move : move) { tmp[j] = old[i]; j++; } else { old[i - j] = old[i]; } } for (int i = j; i < tmp.length; i++) { tmp[i] = old[i - j]; } old = tmp; } return old; }
Generate a Java translation of this Go snippet without changing its computational steps.
package main import "fmt" type ( seq []int sofs []seq ) func newSeq(start, end int) seq { if end < start { end = start } s := make(seq, end-start+1) for i := 0; i < len(s); i++ { s[i] = start + i } return s } func newSofs() sofs { return sofs{seq{}} } func (s sofs) listComp(in seq, expr func(sofs, seq) sofs, pred func(seq) bool) sofs { var s2 sofs for _, t := range expr(s, in) { if pred(t) { s2 = append(s2, t) } } return s2 } func (s sofs) build(t seq) sofs { var u sofs for _, ss := range s { for _, tt := range t { uu := make(seq, len(ss)) copy(uu, ss) uu = append(uu, tt) u = append(u, uu) } } return u } func main() { pt := newSofs() in := newSeq(1, 20) expr := func(s sofs, t seq) sofs { return s.build(t).build(t).build(t) } pred := func(t seq) bool { if len(t) != 3 { return false } return t[0]*t[0]+t[1]*t[1] == t[2]*t[2] && t[0] < t[1] && t[1] < t[2] } pt = pt.listComp(in, expr, pred) fmt.Println(pt) }
import java.util.Arrays; import java.util.List; import static java.util.function.Function.identity; import static java.util.stream.Collectors.toList; import static java.util.stream.IntStream.range; public interface PythagComp{ static void main(String... args){ System.out.println(run(20)); } static List<List<Integer>> run(int n){ return range(1, n).mapToObj( x -> range(x, n).mapToObj( y -> range(y, n).mapToObj( z -> new Integer[]{x, y, z} ) ) ) .flatMap(identity()) .flatMap(identity()) .filter(a -> a[0]*a[0] + a[1]*a[1] == a[2]*a[2]) .map(Arrays::asList) .collect(toList()) ; } }
Write the same algorithm in Java as shown in this Go implementation.
package main import "fmt" var a = []int{170, 45, 75, -90, -802, 24, 2, 66} func main() { fmt.Println("before:", a) selectionSort(a) fmt.Println("after: ", a) } func selectionSort(a []int) { last := len(a) - 1 for i := 0; i < last; i++ { aMin := a[i] iMin := i for j := i + 1; j < len(a); j++ { if a[j] < aMin { aMin = a[j] iMin = j } } a[i], a[iMin] = aMin, a[i] } }
public static void sort(int[] nums){ for(int currentPlace = 0;currentPlace<nums.length-1;currentPlace++){ int smallest = Integer.MAX_VALUE; int smallestAt = currentPlace+1; for(int check = currentPlace; check<nums.length;check++){ if(nums[check]<smallest){ smallestAt = check; smallest = nums[check]; } } int temp = nums[currentPlace]; nums[currentPlace] = nums[smallestAt]; nums[smallestAt] = temp; } }
Change the following Go code into Java without altering its purpose.
package main import ( "fmt" "log" "math/big" ) func jacobi(a, n uint64) int { if n%2 == 0 { log.Fatal("'n' must be a positive odd integer") } a %= n result := 1 for a != 0 { for a%2 == 0 { a /= 2 nn := n % 8 if nn == 3 || nn == 5 { result = -result } } a, n = n, a if a%4 == 3 && n%4 == 3 { result = -result } a %= n } if n == 1 { return result } return 0 } func main() { fmt.Println("Using hand-coded version:") fmt.Println("n/a 0 1 2 3 4 5 6 7 8 9") fmt.Println("---------------------------------") for n := uint64(1); n <= 17; n += 2 { fmt.Printf("%2d ", n) for a := uint64(0); a <= 9; a++ { fmt.Printf(" % d", jacobi(a, n)) } fmt.Println() } ba, bn := new(big.Int), new(big.Int) fmt.Println("\nUsing standard library function:") fmt.Println("n/a 0 1 2 3 4 5 6 7 8 9") fmt.Println("---------------------------------") for n := uint64(1); n <= 17; n += 2 { fmt.Printf("%2d ", n) for a := uint64(0); a <= 9; a++ { ba.SetUint64(a) bn.SetUint64(n) fmt.Printf(" % d", big.Jacobi(ba, bn)) } fmt.Println() } }
public class JacobiSymbol { public static void main(String[] args) { int max = 30; System.out.printf("n\\k "); for ( int k = 1 ; k <= max ; k++ ) { System.out.printf("%2d ", k); } System.out.printf("%n"); for ( int n = 1 ; n <= max ; n += 2 ) { System.out.printf("%2d ", n); for ( int k = 1 ; k <= max ; k++ ) { System.out.printf("%2d ", jacobiSymbol(k, n)); } System.out.printf("%n"); } } private static int jacobiSymbol(int k, int n) { if ( k < 0 || n % 2 == 0 ) { throw new IllegalArgumentException("Invalid value. k = " + k + ", n = " + n); } k %= n; int jacobi = 1; while ( k > 0 ) { while ( k % 2 == 0 ) { k /= 2; int r = n % 8; if ( r == 3 || r == 5 ) { jacobi = -jacobi; } } int temp = n; n = k; k = temp; if ( k % 4 == 3 && n % 4 == 3 ) { jacobi = -jacobi; } k %= n; } if ( n == 1 ) { return jacobi; } return 0; } }
Rewrite this program in Java while keeping its functionality equivalent to the Go version.
package main import ( "fmt" "log" "math/big" ) func jacobi(a, n uint64) int { if n%2 == 0 { log.Fatal("'n' must be a positive odd integer") } a %= n result := 1 for a != 0 { for a%2 == 0 { a /= 2 nn := n % 8 if nn == 3 || nn == 5 { result = -result } } a, n = n, a if a%4 == 3 && n%4 == 3 { result = -result } a %= n } if n == 1 { return result } return 0 } func main() { fmt.Println("Using hand-coded version:") fmt.Println("n/a 0 1 2 3 4 5 6 7 8 9") fmt.Println("---------------------------------") for n := uint64(1); n <= 17; n += 2 { fmt.Printf("%2d ", n) for a := uint64(0); a <= 9; a++ { fmt.Printf(" % d", jacobi(a, n)) } fmt.Println() } ba, bn := new(big.Int), new(big.Int) fmt.Println("\nUsing standard library function:") fmt.Println("n/a 0 1 2 3 4 5 6 7 8 9") fmt.Println("---------------------------------") for n := uint64(1); n <= 17; n += 2 { fmt.Printf("%2d ", n) for a := uint64(0); a <= 9; a++ { ba.SetUint64(a) bn.SetUint64(n) fmt.Printf(" % d", big.Jacobi(ba, bn)) } fmt.Println() } }
public class JacobiSymbol { public static void main(String[] args) { int max = 30; System.out.printf("n\\k "); for ( int k = 1 ; k <= max ; k++ ) { System.out.printf("%2d ", k); } System.out.printf("%n"); for ( int n = 1 ; n <= max ; n += 2 ) { System.out.printf("%2d ", n); for ( int k = 1 ; k <= max ; k++ ) { System.out.printf("%2d ", jacobiSymbol(k, n)); } System.out.printf("%n"); } } private static int jacobiSymbol(int k, int n) { if ( k < 0 || n % 2 == 0 ) { throw new IllegalArgumentException("Invalid value. k = " + k + ", n = " + n); } k %= n; int jacobi = 1; while ( k > 0 ) { while ( k % 2 == 0 ) { k /= 2; int r = n % 8; if ( r == 3 || r == 5 ) { jacobi = -jacobi; } } int temp = n; n = k; k = temp; if ( k % 4 == 3 && n % 4 == 3 ) { jacobi = -jacobi; } k %= n; } if ( n == 1 ) { return jacobi; } return 0; } }
Transform the following Go implementation into Java, maintaining the same output and logic.
package main import ( "fmt" "math" "math/rand" "sort" "time" ) type point []float64 func (p point) sqd(q point) float64 { var sum float64 for dim, pCoord := range p { d := pCoord - q[dim] sum += d * d } return sum } type kdNode struct { domElt point split int left, right *kdNode } type kdTree struct { n *kdNode bounds hyperRect } type hyperRect struct { min, max point } func (hr hyperRect) copy() hyperRect { return hyperRect{append(point{}, hr.min...), append(point{}, hr.max...)} } func newKd(pts []point, bounds hyperRect) kdTree { var nk2 func([]point, int) *kdNode nk2 = func(exset []point, split int) *kdNode { if len(exset) == 0 { return nil } sort.Sort(part{exset, split}) m := len(exset) / 2 d := exset[m] for m+1 < len(exset) && exset[m+1][split] == d[split] { m++ } s2 := split + 1 if s2 == len(d) { s2 = 0 } return &kdNode{d, split, nk2(exset[:m], s2), nk2(exset[m+1:], s2)} } return kdTree{nk2(pts, 0), bounds} } type part struct { pts []point dPart int } func (p part) Len() int { return len(p.pts) } func (p part) Less(i, j int) bool { return p.pts[i][p.dPart] < p.pts[j][p.dPart] } func (p part) Swap(i, j int) { p.pts[i], p.pts[j] = p.pts[j], p.pts[i] } func (t kdTree) nearest(p point) (best point, bestSqd float64, nv int) { return nn(t.n, p, t.bounds, math.Inf(1)) } func nn(kd *kdNode, target point, hr hyperRect, maxDistSqd float64) (nearest point, distSqd float64, nodesVisited int) { if kd == nil { return nil, math.Inf(1), 0 } nodesVisited++ s := kd.split pivot := kd.domElt leftHr := hr.copy() rightHr := hr.copy() leftHr.max[s] = pivot[s] rightHr.min[s] = pivot[s] targetInLeft := target[s] <= pivot[s] var nearerKd, furtherKd *kdNode var nearerHr, furtherHr hyperRect if targetInLeft { nearerKd, nearerHr = kd.left, leftHr furtherKd, furtherHr = kd.right, rightHr } else { nearerKd, nearerHr = kd.right, rightHr furtherKd, furtherHr = kd.left, leftHr } var nv int nearest, distSqd, nv = nn(nearerKd, target, nearerHr, maxDistSqd) nodesVisited += nv if distSqd < maxDistSqd { maxDistSqd = distSqd } d := pivot[s] - target[s] d *= d if d > maxDistSqd { return } if d = pivot.sqd(target); d < distSqd { nearest = pivot distSqd = d maxDistSqd = distSqd } tempNearest, tempSqd, nv := nn(furtherKd, target, furtherHr, maxDistSqd) nodesVisited += nv if tempSqd < distSqd { nearest = tempNearest distSqd = tempSqd } return } func main() { rand.Seed(time.Now().Unix()) kd := newKd([]point{{2, 3}, {5, 4}, {9, 6}, {4, 7}, {8, 1}, {7, 2}}, hyperRect{point{0, 0}, point{10, 10}}) showNearest("WP example data", kd, point{9, 2}) kd = newKd(randomPts(3, 1000), hyperRect{point{0, 0, 0}, point{1, 1, 1}}) showNearest("1000 random 3d points", kd, randomPt(3)) } func randomPt(dim int) point { p := make(point, dim) for d := range p { p[d] = rand.Float64() } return p } func randomPts(dim, n int) []point { p := make([]point, n) for i := range p { p[i] = randomPt(dim) } return p } func showNearest(heading string, kd kdTree, p point) { fmt.Println() fmt.Println(heading) fmt.Println("point: ", p) nn, ssq, nv := kd.nearest(p) fmt.Println("nearest neighbor:", nn) fmt.Println("distance: ", math.Sqrt(ssq)) fmt.Println("nodes visited: ", nv) }
import java.util.*; public class KdTree { private int dimensions_; private Node root_ = null; private Node best_ = null; private double bestDistance_ = 0; private int visited_ = 0; public KdTree(int dimensions, List<Node> nodes) { dimensions_ = dimensions; root_ = makeTree(nodes, 0, nodes.size(), 0); } public Node findNearest(Node target) { if (root_ == null) throw new IllegalStateException("Tree is empty!"); best_ = null; visited_ = 0; bestDistance_ = 0; nearest(root_, target, 0); return best_; } public int visited() { return visited_; } public double distance() { return Math.sqrt(bestDistance_); } private void nearest(Node root, Node target, int index) { if (root == null) return; ++visited_; double d = root.distance(target); if (best_ == null || d < bestDistance_) { bestDistance_ = d; best_ = root; } if (bestDistance_ == 0) return; double dx = root.get(index) - target.get(index); index = (index + 1) % dimensions_; nearest(dx > 0 ? root.left_ : root.right_, target, index); if (dx * dx >= bestDistance_) return; nearest(dx > 0 ? root.right_ : root.left_, target, index); } private Node makeTree(List<Node> nodes, int begin, int end, int index) { if (end <= begin) return null; int n = begin + (end - begin)/2; Node node = QuickSelect.select(nodes, begin, end - 1, n, new NodeComparator(index)); index = (index + 1) % dimensions_; node.left_ = makeTree(nodes, begin, n, index); node.right_ = makeTree(nodes, n + 1, end, index); return node; } private static class NodeComparator implements Comparator<Node> { private int index_; private NodeComparator(int index) { index_ = index; } public int compare(Node n1, Node n2) { return Double.compare(n1.get(index_), n2.get(index_)); } } public static class Node { private double[] coords_; private Node left_ = null; private Node right_ = null; public Node(double[] coords) { coords_ = coords; } public Node(double x, double y) { this(new double[]{x, y}); } public Node(double x, double y, double z) { this(new double[]{x, y, z}); } double get(int index) { return coords_[index]; } double distance(Node node) { double dist = 0; for (int i = 0; i < coords_.length; ++i) { double d = coords_[i] - node.coords_[i]; dist += d * d; } return dist; } public String toString() { StringBuilder s = new StringBuilder("("); for (int i = 0; i < coords_.length; ++i) { if (i > 0) s.append(", "); s.append(coords_[i]); } s.append(')'); return s.toString(); } } }
Translate the given Go code snippet into Java without altering its behavior.
package main import ( "fmt" "math" "math/rand" "sort" "time" ) type point []float64 func (p point) sqd(q point) float64 { var sum float64 for dim, pCoord := range p { d := pCoord - q[dim] sum += d * d } return sum } type kdNode struct { domElt point split int left, right *kdNode } type kdTree struct { n *kdNode bounds hyperRect } type hyperRect struct { min, max point } func (hr hyperRect) copy() hyperRect { return hyperRect{append(point{}, hr.min...), append(point{}, hr.max...)} } func newKd(pts []point, bounds hyperRect) kdTree { var nk2 func([]point, int) *kdNode nk2 = func(exset []point, split int) *kdNode { if len(exset) == 0 { return nil } sort.Sort(part{exset, split}) m := len(exset) / 2 d := exset[m] for m+1 < len(exset) && exset[m+1][split] == d[split] { m++ } s2 := split + 1 if s2 == len(d) { s2 = 0 } return &kdNode{d, split, nk2(exset[:m], s2), nk2(exset[m+1:], s2)} } return kdTree{nk2(pts, 0), bounds} } type part struct { pts []point dPart int } func (p part) Len() int { return len(p.pts) } func (p part) Less(i, j int) bool { return p.pts[i][p.dPart] < p.pts[j][p.dPart] } func (p part) Swap(i, j int) { p.pts[i], p.pts[j] = p.pts[j], p.pts[i] } func (t kdTree) nearest(p point) (best point, bestSqd float64, nv int) { return nn(t.n, p, t.bounds, math.Inf(1)) } func nn(kd *kdNode, target point, hr hyperRect, maxDistSqd float64) (nearest point, distSqd float64, nodesVisited int) { if kd == nil { return nil, math.Inf(1), 0 } nodesVisited++ s := kd.split pivot := kd.domElt leftHr := hr.copy() rightHr := hr.copy() leftHr.max[s] = pivot[s] rightHr.min[s] = pivot[s] targetInLeft := target[s] <= pivot[s] var nearerKd, furtherKd *kdNode var nearerHr, furtherHr hyperRect if targetInLeft { nearerKd, nearerHr = kd.left, leftHr furtherKd, furtherHr = kd.right, rightHr } else { nearerKd, nearerHr = kd.right, rightHr furtherKd, furtherHr = kd.left, leftHr } var nv int nearest, distSqd, nv = nn(nearerKd, target, nearerHr, maxDistSqd) nodesVisited += nv if distSqd < maxDistSqd { maxDistSqd = distSqd } d := pivot[s] - target[s] d *= d if d > maxDistSqd { return } if d = pivot.sqd(target); d < distSqd { nearest = pivot distSqd = d maxDistSqd = distSqd } tempNearest, tempSqd, nv := nn(furtherKd, target, furtherHr, maxDistSqd) nodesVisited += nv if tempSqd < distSqd { nearest = tempNearest distSqd = tempSqd } return } func main() { rand.Seed(time.Now().Unix()) kd := newKd([]point{{2, 3}, {5, 4}, {9, 6}, {4, 7}, {8, 1}, {7, 2}}, hyperRect{point{0, 0}, point{10, 10}}) showNearest("WP example data", kd, point{9, 2}) kd = newKd(randomPts(3, 1000), hyperRect{point{0, 0, 0}, point{1, 1, 1}}) showNearest("1000 random 3d points", kd, randomPt(3)) } func randomPt(dim int) point { p := make(point, dim) for d := range p { p[d] = rand.Float64() } return p } func randomPts(dim, n int) []point { p := make([]point, n) for i := range p { p[i] = randomPt(dim) } return p } func showNearest(heading string, kd kdTree, p point) { fmt.Println() fmt.Println(heading) fmt.Println("point: ", p) nn, ssq, nv := kd.nearest(p) fmt.Println("nearest neighbor:", nn) fmt.Println("distance: ", math.Sqrt(ssq)) fmt.Println("nodes visited: ", nv) }
import java.util.*; public class KdTree { private int dimensions_; private Node root_ = null; private Node best_ = null; private double bestDistance_ = 0; private int visited_ = 0; public KdTree(int dimensions, List<Node> nodes) { dimensions_ = dimensions; root_ = makeTree(nodes, 0, nodes.size(), 0); } public Node findNearest(Node target) { if (root_ == null) throw new IllegalStateException("Tree is empty!"); best_ = null; visited_ = 0; bestDistance_ = 0; nearest(root_, target, 0); return best_; } public int visited() { return visited_; } public double distance() { return Math.sqrt(bestDistance_); } private void nearest(Node root, Node target, int index) { if (root == null) return; ++visited_; double d = root.distance(target); if (best_ == null || d < bestDistance_) { bestDistance_ = d; best_ = root; } if (bestDistance_ == 0) return; double dx = root.get(index) - target.get(index); index = (index + 1) % dimensions_; nearest(dx > 0 ? root.left_ : root.right_, target, index); if (dx * dx >= bestDistance_) return; nearest(dx > 0 ? root.right_ : root.left_, target, index); } private Node makeTree(List<Node> nodes, int begin, int end, int index) { if (end <= begin) return null; int n = begin + (end - begin)/2; Node node = QuickSelect.select(nodes, begin, end - 1, n, new NodeComparator(index)); index = (index + 1) % dimensions_; node.left_ = makeTree(nodes, begin, n, index); node.right_ = makeTree(nodes, n + 1, end, index); return node; } private static class NodeComparator implements Comparator<Node> { private int index_; private NodeComparator(int index) { index_ = index; } public int compare(Node n1, Node n2) { return Double.compare(n1.get(index_), n2.get(index_)); } } public static class Node { private double[] coords_; private Node left_ = null; private Node right_ = null; public Node(double[] coords) { coords_ = coords; } public Node(double x, double y) { this(new double[]{x, y}); } public Node(double x, double y, double z) { this(new double[]{x, y, z}); } double get(int index) { return coords_[index]; } double distance(Node node) { double dist = 0; for (int i = 0; i < coords_.length; ++i) { double d = coords_[i] - node.coords_[i]; dist += d * d; } return dist; } public String toString() { StringBuilder s = new StringBuilder("("); for (int i = 0; i < coords_.length; ++i) { if (i > 0) s.append(", "); s.append(coords_[i]); } s.append(')'); return s.toString(); } } }
Produce a functionally identical Java code for the snippet given in Go.
package main import "fmt" func main() { for _, i := range []int{1, 2, 3, 4, 5} { fmt.Println(i * i) } }
public class ArrayCallback7 { interface IntConsumer { void run(int x); } interface IntToInt { int run(int x); } static void forEach(int[] arr, IntConsumer consumer) { for (int i : arr) { consumer.run(i); } } static void update(int[] arr, IntToInt mapper) { for (int i = 0; i < arr.length; i++) { arr[i] = mapper.run(arr[i]); } } public static void main(String[] args) { int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; forEach(numbers, new IntConsumer() { public void run(int x) { System.out.println(x); } }); update(numbers, new IntToInt() { @Override public int run(int x) { return x * x; } }); forEach(numbers, new IntConsumer() { public void run(int x) { System.out.println(x); } }); } }
Translate this program into Java but keep the logic exactly as in Go.
package main import "fmt" func main() { for _, i := range []int{1, 2, 3, 4, 5} { fmt.Println(i * i) } }
public class ArrayCallback7 { interface IntConsumer { void run(int x); } interface IntToInt { int run(int x); } static void forEach(int[] arr, IntConsumer consumer) { for (int i : arr) { consumer.run(i); } } static void update(int[] arr, IntToInt mapper) { for (int i = 0; i < arr.length; i++) { arr[i] = mapper.run(arr[i]); } } public static void main(String[] args) { int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; forEach(numbers, new IntConsumer() { public void run(int x) { System.out.println(x); } }); update(numbers, new IntToInt() { @Override public int run(int x) { return x * x; } }); forEach(numbers, new IntConsumer() { public void run(int x) { System.out.println(x); } }); } }
Convert the following code from Go to Java, ensuring the logic remains intact.
package main import ( "log" "math/rand" "sync" "time" ) var ( instance string once sync.Once ) func claim(color string, w *sync.WaitGroup) { time.Sleep(time.Duration(rand.Intn(1e8))) log.Println("trying to claim", color) once.Do(func() { instance = color }) log.Printf("tried %s. instance: %s", color, instance) w.Done() } func main() { rand.Seed(time.Now().Unix()) var w sync.WaitGroup w.Add(2) go claim("red", &w) go claim("blue", &w) w.Wait() log.Println("after trying both, instance =", instance) }
class Singleton { private static Singleton myInstance; public static Singleton getInstance() { if (myInstance == null) { synchronized(Singleton.class) { if (myInstance == null) { myInstance = new Singleton(); } } } return myInstance; } protected Singleton() { } }
Change the following Go code into Java without altering its purpose.
package main import ( "fmt" "math" ) type interval struct { lower, upper float64 } func stepAway(x float64) interval { return interval { math.Nextafter(x, math.Inf(-1)), math.Nextafter(x, math.Inf(1))} } func safeAdd(a, b float64) interval { return stepAway(a + b) } func main() { a, b := 1.2, .03 fmt.Println(a, b, safeAdd(a, b)) }
public class SafeAddition { private static double stepDown(double d) { return Math.nextAfter(d, Double.NEGATIVE_INFINITY); } private static double stepUp(double d) { return Math.nextUp(d); } private static double[] safeAdd(double a, double b) { return new double[]{stepDown(a + b), stepUp(a + b)}; } public static void main(String[] args) { double a = 1.2; double b = 0.03; double[] result = safeAdd(a, b); System.out.printf("(%.2f + %.2f) is in the range %.16f..%.16f", a, b, result[0], result[1]); } }
Port the provided Go code into Java while preserving the original functionality.
package dogs import "fmt" var dog = "Salt" var Dog = "Pepper" var DOG = "Mustard" func PackageSees() map[*string]int { fmt.Println("Package sees:", dog, Dog, DOG) return map[*string]int{&dog: 1, &Dog: 1, &DOG: 1} }
String dog = "Benjamin"; String Dog = "Samba"; String DOG = "Bernie"; @Inject Console console; console.print($"There are three dogs named {dog}, {Dog}, and {DOG}");
Transform the following Go implementation into Java, maintaining the same output and logic.
for i := 10; i >= 0; i-- { fmt.Println(i) }
for (int i = 10; i >= 0; i--) { System.out.println(i); }
Can you help me rewrite this code in Java instead of Go, keeping it the same logically?
import "io/ioutil" func main() { ioutil.WriteFile("path/to/your.file", []byte("data"), 0644) }
import java.io.*; public class Test { public static void main(String[] args) throws IOException { try (BufferedWriter bw = new BufferedWriter(new FileWriter("test.txt"))) { bw.write("abc"); } } }
Write a version of this Go function in Java with identical behavior.
package main import "fmt" func main() { for i := 1; i <= 5; i++ { for j := 1; j <= i; j++ { fmt.Printf("*") } fmt.Printf("\n") } }
for (Integer i = 0; i < 5; i++) { String line = ''; for (Integer j = 0; j < i; j++) { line += '*'; } System.debug(line); } List<String> lines = new List<String> { '*', '**', '***', '****', '*****' }; for (String line : lines) { System.debug(line); }
Translate this program into Java but keep the logic exactly as in Go.
package main import "fmt" func reverse(s uint64) uint64 { e := uint64(0) for s > 0 { e = e*10 + (s % 10) s /= 10 } return e } func commatize(n uint) 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 ord(n uint) string { var suffix string if n > 10 && ((n-11)%100 == 0 || (n-12)%100 == 0 || (n-13)%100 == 0) { suffix = "th" } else { switch n % 10 { case 1: suffix = "st" case 2: suffix = "nd" case 3: suffix = "rd" default: suffix = "th" } } return fmt.Sprintf("%s%s", commatize(n), suffix) } func main() { const max = 10_000_000 data := [][3]uint{{1, 20, 7}, {86, 100, 8}, {991, 1000, 10}, {9995, 10000, 12}, {1e5, 1e5, 14}, {1e6, 1e6, 16}, {1e7, 1e7, 18}} results := make(map[uint][]uint64) for _, d := range data { for i := d[0]; i <= d[1]; i++ { results[i] = make([]uint64, 9) } } var p uint64 outer: for d := uint64(1); d < 10; d++ { count := uint(0) pow := uint64(1) fl := d * 11 for nd := 3; nd < 20; nd++ { slim := (d + 1) * pow for s := d * pow; s < slim; s++ { e := reverse(s) mlim := uint64(1) if nd%2 == 1 { mlim = 10 } for m := uint64(0); m < mlim; m++ { if nd%2 == 0 { p = s*pow*10 + e } else { p = s*pow*100 + m*pow*10 + e } if p%fl == 0 { count++ if _, ok := results[count]; ok { results[count][d-1] = p } if count == max { continue outer } } } } if nd%2 == 1 { pow *= 10 } } } for _, d := range data { if d[0] != d[1] { fmt.Printf("%s to %s palindromic gapful numbers (> 100) ending with:\n", ord(d[0]), ord(d[1])) } else { fmt.Printf("%s palindromic gapful number (> 100) ending with:\n", ord(d[0])) } for i := 1; i <= 9; i++ { fmt.Printf("%d: ", i) for j := d[0]; j <= d[1]; j++ { fmt.Printf("%*d ", d[2], results[j][i-1]) } fmt.Println() } fmt.Println() } }
import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class PalindromicGapfulNumbers { public static void main(String[] args) { System.out.println("First 20 palindromic gapful numbers ending in:"); displayMap(getPalindromicGapfulEnding(20, 20)); System.out.printf("%nLast 15 of first 100 palindromic gapful numbers ending in:%n"); displayMap(getPalindromicGapfulEnding(15, 100)); System.out.printf("%nLast 10 of first 1000 palindromic gapful numbers ending in:%n"); displayMap(getPalindromicGapfulEnding(10, 1000)); } private static void displayMap(Map<Integer,List<Long>> map) { for ( int key = 1 ; key <= 9 ; key++ ) { System.out.println(key + " : " + map.get(key)); } } public static Map<Integer,List<Long>> getPalindromicGapfulEnding(int countReturned, int firstHowMany) { Map<Integer,List<Long>> map = new HashMap<>(); Map<Integer,Integer> mapCount = new HashMap<>(); for ( int i = 1 ; i <= 9 ; i++ ) { map.put(i, new ArrayList<>()); mapCount.put(i, 0); } boolean notPopulated = true; for ( long n = 101 ; notPopulated ; n = nextPalindrome(n) ) { if ( isGapful(n) ) { int index = (int) (n % 10); if ( mapCount.get(index) < firstHowMany ) { map.get(index).add(n); mapCount.put(index, mapCount.get(index) + 1); if ( map.get(index).size() > countReturned ) { map.get(index).remove(0); } } boolean finished = true; for ( int i = 1 ; i <= 9 ; i++ ) { if ( mapCount.get(i) < firstHowMany ) { finished = false; break; } } if ( finished ) { notPopulated = false; } } } return map; } public static boolean isGapful(long n) { String s = Long.toString(n); return n % Long.parseLong("" + s.charAt(0) + s.charAt(s.length()-1)) == 0; } public static int length(long n) { int length = 0; while ( n > 0 ) { length += 1; n /= 10; } return length; } public static long nextPalindrome(long n) { int length = length(n); if ( length % 2 == 0 ) { length /= 2; while ( length > 0 ) { n /= 10; length--; } n += 1; if ( powerTen(n) ) { return Long.parseLong(n + reverse(n/10)); } return Long.parseLong(n + reverse(n)); } length = (length - 1) / 2; while ( length > 0 ) { n /= 10; length--; } n += 1; if ( powerTen(n) ) { return Long.parseLong(n + reverse(n/100)); } return Long.parseLong(n + reverse(n/10)); } private static boolean powerTen(long n) { while ( n > 9 && n % 10 == 0 ) { n /= 10; } return n == 1; } private static String reverse(long n) { return (new StringBuilder(n + "")).reverse().toString(); } }
Transform the following Go implementation into Java, maintaining the same output and logic.
package main import "fmt" func reverse(s uint64) uint64 { e := uint64(0) for s > 0 { e = e*10 + (s % 10) s /= 10 } return e } func commatize(n uint) 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 ord(n uint) string { var suffix string if n > 10 && ((n-11)%100 == 0 || (n-12)%100 == 0 || (n-13)%100 == 0) { suffix = "th" } else { switch n % 10 { case 1: suffix = "st" case 2: suffix = "nd" case 3: suffix = "rd" default: suffix = "th" } } return fmt.Sprintf("%s%s", commatize(n), suffix) } func main() { const max = 10_000_000 data := [][3]uint{{1, 20, 7}, {86, 100, 8}, {991, 1000, 10}, {9995, 10000, 12}, {1e5, 1e5, 14}, {1e6, 1e6, 16}, {1e7, 1e7, 18}} results := make(map[uint][]uint64) for _, d := range data { for i := d[0]; i <= d[1]; i++ { results[i] = make([]uint64, 9) } } var p uint64 outer: for d := uint64(1); d < 10; d++ { count := uint(0) pow := uint64(1) fl := d * 11 for nd := 3; nd < 20; nd++ { slim := (d + 1) * pow for s := d * pow; s < slim; s++ { e := reverse(s) mlim := uint64(1) if nd%2 == 1 { mlim = 10 } for m := uint64(0); m < mlim; m++ { if nd%2 == 0 { p = s*pow*10 + e } else { p = s*pow*100 + m*pow*10 + e } if p%fl == 0 { count++ if _, ok := results[count]; ok { results[count][d-1] = p } if count == max { continue outer } } } } if nd%2 == 1 { pow *= 10 } } } for _, d := range data { if d[0] != d[1] { fmt.Printf("%s to %s palindromic gapful numbers (> 100) ending with:\n", ord(d[0]), ord(d[1])) } else { fmt.Printf("%s palindromic gapful number (> 100) ending with:\n", ord(d[0])) } for i := 1; i <= 9; i++ { fmt.Printf("%d: ", i) for j := d[0]; j <= d[1]; j++ { fmt.Printf("%*d ", d[2], results[j][i-1]) } fmt.Println() } fmt.Println() } }
import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class PalindromicGapfulNumbers { public static void main(String[] args) { System.out.println("First 20 palindromic gapful numbers ending in:"); displayMap(getPalindromicGapfulEnding(20, 20)); System.out.printf("%nLast 15 of first 100 palindromic gapful numbers ending in:%n"); displayMap(getPalindromicGapfulEnding(15, 100)); System.out.printf("%nLast 10 of first 1000 palindromic gapful numbers ending in:%n"); displayMap(getPalindromicGapfulEnding(10, 1000)); } private static void displayMap(Map<Integer,List<Long>> map) { for ( int key = 1 ; key <= 9 ; key++ ) { System.out.println(key + " : " + map.get(key)); } } public static Map<Integer,List<Long>> getPalindromicGapfulEnding(int countReturned, int firstHowMany) { Map<Integer,List<Long>> map = new HashMap<>(); Map<Integer,Integer> mapCount = new HashMap<>(); for ( int i = 1 ; i <= 9 ; i++ ) { map.put(i, new ArrayList<>()); mapCount.put(i, 0); } boolean notPopulated = true; for ( long n = 101 ; notPopulated ; n = nextPalindrome(n) ) { if ( isGapful(n) ) { int index = (int) (n % 10); if ( mapCount.get(index) < firstHowMany ) { map.get(index).add(n); mapCount.put(index, mapCount.get(index) + 1); if ( map.get(index).size() > countReturned ) { map.get(index).remove(0); } } boolean finished = true; for ( int i = 1 ; i <= 9 ; i++ ) { if ( mapCount.get(i) < firstHowMany ) { finished = false; break; } } if ( finished ) { notPopulated = false; } } } return map; } public static boolean isGapful(long n) { String s = Long.toString(n); return n % Long.parseLong("" + s.charAt(0) + s.charAt(s.length()-1)) == 0; } public static int length(long n) { int length = 0; while ( n > 0 ) { length += 1; n /= 10; } return length; } public static long nextPalindrome(long n) { int length = length(n); if ( length % 2 == 0 ) { length /= 2; while ( length > 0 ) { n /= 10; length--; } n += 1; if ( powerTen(n) ) { return Long.parseLong(n + reverse(n/10)); } return Long.parseLong(n + reverse(n)); } length = (length - 1) / 2; while ( length > 0 ) { n /= 10; length--; } n += 1; if ( powerTen(n) ) { return Long.parseLong(n + reverse(n/100)); } return Long.parseLong(n + reverse(n/10)); } private static boolean powerTen(long n) { while ( n > 9 && n % 10 == 0 ) { n /= 10; } return n == 1; } private static String reverse(long n) { return (new StringBuilder(n + "")).reverse().toString(); } }
Can you help me rewrite this code in Java instead of Go, keeping it the same logically?
package main import ( "fmt" "image" "image/color" "image/draw" "image/png" "os" ) func main() { const order = 8 const width = 1 << order const margin = 10 bounds := image.Rect(-margin, -margin, width+2*margin, width+2*margin) im := image.NewGray(bounds) gBlack := color.Gray{0} gWhite := color.Gray{255} draw.Draw(im, bounds, image.NewUniform(gWhite), image.ZP, draw.Src) for y := 0; y < width; y++ { for x := 0; x < width; x++ { if x&y == 0 { im.SetGray(x, y, gBlack) } } } f, err := os.Create("sierpinski.png") if err != nil { fmt.Println(err) return } if err = png.Encode(f, im); err != nil { fmt.Println(err) } if err = f.Close(); err != nil { fmt.Println(err) } }
import javax.swing.*; import java.awt.*; class SierpinskyTriangle { public static void main(String[] args) { int i = 3; if(args.length >= 1) { try { i = Integer.parseInt(args[0]); } catch(NumberFormatException e) { System.out.println("Usage: 'java SierpinskyTriangle [level]'\nNow setting level to "+i); } } final int level = i; JFrame frame = new JFrame("Sierpinsky Triangle - Java"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel panel = new JPanel() { @Override public void paintComponent(Graphics g) { g.setColor(Color.BLACK); drawSierpinskyTriangle(level, 20, 20, 360, (Graphics2D)g); } }; panel.setPreferredSize(new Dimension(400, 400)); frame.add(panel); frame.pack(); frame.setResizable(false); frame.setLocationRelativeTo(null); frame.setVisible(true); } private static void drawSierpinskyTriangle(int level, int x, int y, int size, Graphics2D g) { if(level <= 0) return; g.drawLine(x, y, x+size, y); g.drawLine(x, y, x, y+size); g.drawLine(x+size, y, x, y+size); drawSierpinskyTriangle(level-1, x, y, size/2, g); drawSierpinskyTriangle(level-1, x+size/2, y, size/2, g); drawSierpinskyTriangle(level-1, x, y+size/2, size/2, g); } }
Convert the following code from Go to Java, ensuring the logic remains intact.
package main import ( "fmt" "image" "image/color" "image/draw" "image/png" "os" ) func main() { const order = 8 const width = 1 << order const margin = 10 bounds := image.Rect(-margin, -margin, width+2*margin, width+2*margin) im := image.NewGray(bounds) gBlack := color.Gray{0} gWhite := color.Gray{255} draw.Draw(im, bounds, image.NewUniform(gWhite), image.ZP, draw.Src) for y := 0; y < width; y++ { for x := 0; x < width; x++ { if x&y == 0 { im.SetGray(x, y, gBlack) } } } f, err := os.Create("sierpinski.png") if err != nil { fmt.Println(err) return } if err = png.Encode(f, im); err != nil { fmt.Println(err) } if err = f.Close(); err != nil { fmt.Println(err) } }
import javax.swing.*; import java.awt.*; class SierpinskyTriangle { public static void main(String[] args) { int i = 3; if(args.length >= 1) { try { i = Integer.parseInt(args[0]); } catch(NumberFormatException e) { System.out.println("Usage: 'java SierpinskyTriangle [level]'\nNow setting level to "+i); } } final int level = i; JFrame frame = new JFrame("Sierpinsky Triangle - Java"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel panel = new JPanel() { @Override public void paintComponent(Graphics g) { g.setColor(Color.BLACK); drawSierpinskyTriangle(level, 20, 20, 360, (Graphics2D)g); } }; panel.setPreferredSize(new Dimension(400, 400)); frame.add(panel); frame.pack(); frame.setResizable(false); frame.setLocationRelativeTo(null); frame.setVisible(true); } private static void drawSierpinskyTriangle(int level, int x, int y, int size, Graphics2D g) { if(level <= 0) return; g.drawLine(x, y, x+size, y); g.drawLine(x, y, x, y+size); g.drawLine(x+size, y, x, y+size); drawSierpinskyTriangle(level-1, x, y, size/2, g); drawSierpinskyTriangle(level-1, x+size/2, y, size/2, g); drawSierpinskyTriangle(level-1, x, y+size/2, size/2, g); } }
Change the following Go code into Java without altering its purpose.
package main import "fmt" const ( m = iota c cm cmc ) func ncs(s []int) [][]int { if len(s) < 3 { return nil } return append(n2(nil, s[1:], m), n2([]int{s[0]}, s[1:], c)...) } var skip = []int{m, cm, cm, cmc} var incl = []int{c, c, cmc, cmc} func n2(ss, tail []int, seq int) [][]int { if len(tail) == 0 { if seq != cmc { return nil } return [][]int{ss} } return append(n2(append([]int{}, ss...), tail[1:], skip[seq]), n2(append(ss, tail[0]), tail[1:], incl[seq])...) } func main() { ss := ncs([]int{1, 2, 3, 4}) fmt.Println(len(ss), "non-continuous subsequences:") for _, s := range ss { fmt.Println(" ", s) } }
public class NonContinuousSubsequences { public static void main(String args[]) { seqR("1234", "", 0, 0); } private static void seqR(String s, String c, int i, int added) { if (i == s.length()) { if (c.trim().length() > added) System.out.println(c); } else { seqR(s, c + s.charAt(i), i + 1, added + 1); seqR(s, c + ' ', i + 1, added); } } }
Produce a language-to-language conversion: from Go to Java, same semantics.
package main import ( "github.com/fogleman/gg" "strings" ) func wordFractal(i int) string { if i < 2 { if i == 1 { return "1" } return "" } var f1 strings.Builder f1.WriteString("1") var f2 strings.Builder f2.WriteString("0") for j := i - 2; j >= 1; j-- { tmp := f2.String() f2.WriteString(f1.String()) f1.Reset() f1.WriteString(tmp) } return f2.String() } func draw(dc *gg.Context, x, y, dx, dy float64, wf string) { for i, c := range wf { dc.DrawLine(x, y, x+dx, y+dy) x += dx y += dy if c == '0' { tx := dx dx = dy if i%2 == 0 { dx = -dy } dy = -tx if i%2 == 0 { dy = tx } } } } func main() { dc := gg.NewContext(450, 620) dc.SetRGB(0, 0, 0) dc.Clear() wf := wordFractal(23) draw(dc, 20, 20, 1, 0, wf) dc.SetRGB(0, 1, 0) dc.SetLineWidth(1) dc.Stroke() dc.SavePNG("fib_wordfractal.png") }
import java.awt.*; import javax.swing.*; public class FibonacciWordFractal extends JPanel { String wordFractal; FibonacciWordFractal(int n) { setPreferredSize(new Dimension(450, 620)); setBackground(Color.white); wordFractal = wordFractal(n); } public String wordFractal(int n) { if (n < 2) return n == 1 ? "1" : ""; StringBuilder f1 = new StringBuilder("1"); StringBuilder f2 = new StringBuilder("0"); for (n = n - 2; n > 0; n--) { String tmp = f2.toString(); f2.append(f1); f1.setLength(0); f1.append(tmp); } return f2.toString(); } void drawWordFractal(Graphics2D g, int x, int y, int dx, int dy) { for (int n = 0; n < wordFractal.length(); n++) { g.drawLine(x, y, x + dx, y + dy); x += dx; y += dy; if (wordFractal.charAt(n) == '0') { int tx = dx; dx = (n % 2 == 0) ? -dy : dy; dy = (n % 2 == 0) ? tx : -tx; } } } @Override public void paintComponent(Graphics gg) { super.paintComponent(gg); Graphics2D g = (Graphics2D) gg; g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); drawWordFractal(g, 20, 20, 1, 0); } public static void main(String[] args) { SwingUtilities.invokeLater(() -> { JFrame f = new JFrame(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setTitle("Fibonacci Word Fractal"); f.setResizable(false); f.add(new FibonacciWordFractal(23), BorderLayout.CENTER); f.pack(); f.setLocationRelativeTo(null); f.setVisible(true); }); } }
Can you help me rewrite this code in Java instead of Go, keeping it the same logically?
package main import "fmt" func sieve(limit uint64) []bool { limit++ c := make([]bool, limit) c[0] = true c[1] = true p := uint64(3) for { p2 := p * p if p2 >= limit { break } for i := p2; i < limit; i += 2 * p { c[i] = true } for { p += 2 if !c[p] { break } } } return c } func commatize(n int) string { s := fmt.Sprintf("%d", n) if n < 0 { s = s[1:] } le := len(s) for i := le - 3; i >= 1; i -= 3 { s = s[0:i] + "," + s[i:] } if n >= 0 { return s } return "-" + s } func main() { c := sieve(1e10 - 1) limit := 10 start := 3 twins := 0 for i := 1; i < 11; i++ { for i := start; i < limit; i += 2 { if !c[i] && !c[i-2] { twins++ } } fmt.Printf("Under %14s there are %10s pairs of twin primes.\n", commatize(limit), commatize(twins)) start = limit + 1 limit *= 10 } }
import java.math.BigInteger; import java.util.Scanner; public class twinPrimes { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("Search Size: "); BigInteger max = input.nextBigInteger(); int counter = 0; for(BigInteger x = new BigInteger("3"); x.compareTo(max) <= 0; x = x.add(BigInteger.ONE)){ BigInteger sqrtNum = x.sqrt().add(BigInteger.ONE); if(x.add(BigInteger.TWO).compareTo(max) <= 0) { counter += findPrime(x.add(BigInteger.TWO), x.add(BigInteger.TWO).sqrt().add(BigInteger.ONE)) && findPrime(x, sqrtNum) ? 1 : 0; } } System.out.println(counter + " twin prime pairs."); } public static boolean findPrime(BigInteger x, BigInteger sqrtNum){ for(BigInteger divisor = BigInteger.TWO; divisor.compareTo(sqrtNum) <= 0; divisor = divisor.add(BigInteger.ONE)){ if(x.remainder(divisor).compareTo(BigInteger.ZERO) == 0){ return false; } } return true; } }
Generate a Java translation of this Go snippet without changing its computational steps.
package main import ( "fmt" "math" "math/cmplx" ) func main() { for n := 2; n <= 5; n++ { fmt.Printf("%d roots of 1:\n", n) for _, r := range roots(n) { fmt.Printf(" %18.15f\n", r) } } } func roots(n int) []complex128 { r := make([]complex128, n) for i := 0; i < n; i++ { r[i] = cmplx.Rect(1, 2*math.Pi*float64(i)/float64(n)) } return r }
import java.util.Locale; public class Test { public static void main(String[] a) { for (int n = 2; n < 6; n++) unity(n); } public static void unity(int n) { System.out.printf("%n%d: ", n); for (double angle = 0; angle < 2 * Math.PI; angle += (2 * Math.PI) / n) { double real = Math.cos(angle); if (Math.abs(real) < 1.0E-3) real = 0.0; double imag = Math.sin(angle); if (Math.abs(imag) < 1.0E-3) imag = 0.0; System.out.printf(Locale.US, "(%9f,%9f) ", real, imag); } } }
Write the same code in Java as shown below in Go.
package main import ( "fmt" "math" "math/cmplx" ) func main() { for n := 2; n <= 5; n++ { fmt.Printf("%d roots of 1:\n", n) for _, r := range roots(n) { fmt.Printf(" %18.15f\n", r) } } } func roots(n int) []complex128 { r := make([]complex128, n) for i := 0; i < n; i++ { r[i] = cmplx.Rect(1, 2*math.Pi*float64(i)/float64(n)) } return r }
import java.util.Locale; public class Test { public static void main(String[] a) { for (int n = 2; n < 6; n++) unity(n); } public static void unity(int n) { System.out.printf("%n%d: ", n); for (double angle = 0; angle < 2 * Math.PI; angle += (2 * Math.PI) / n) { double real = Math.cos(angle); if (Math.abs(real) < 1.0E-3) real = 0.0; double imag = Math.sin(angle); if (Math.abs(imag) < 1.0E-3) imag = 0.0; System.out.printf(Locale.US, "(%9f,%9f) ", real, imag); } } }
Port the provided Go code into Java while preserving the original functionality.
package main import "fmt" func d(b byte) byte { if b < '0' || b > '9' { panic("digit 0-9 expected") } return b - '0' } func add(x, y string) string { if len(y) > len(x) { x, y = y, x } b := make([]byte, len(x)+1) var c byte for i := 1; i <= len(x); i++ { if i <= len(y) { c += d(y[len(y)-i]) } s := d(x[len(x)-i]) + c c = s / 10 b[len(b)-i] = (s % 10) + '0' } if c == 0 { return string(b[1:]) } b[0] = c + '0' return string(b) } func mulDigit(x string, y byte) string { if y == '0' { return "0" } y = d(y) b := make([]byte, len(x)+1) var c byte for i := 1; i <= len(x); i++ { s := d(x[len(x)-i])*y + c c = s / 10 b[len(b)-i] = (s % 10) + '0' } if c == 0 { return string(b[1:]) } b[0] = c + '0' return string(b) } func mul(x, y string) string { result := mulDigit(x, y[len(y)-1]) for i, zeros := 2, ""; i <= len(y); i++ { zeros += "0" result = add(result, mulDigit(x, y[len(y)-i])+zeros) } return result } const n = "18446744073709551616" func main() { fmt.Println(mul(n, n)) }
public class LongMult { private static byte[] stringToDigits(String num) { byte[] result = new byte[num.length()]; for (int i = 0; i < num.length(); i++) { char c = num.charAt(i); if (c < '0' || c > '9') { throw new IllegalArgumentException("Invalid digit " + c + " found at position " + i); } result[num.length() - 1 - i] = (byte) (c - '0'); } return result; } public static String longMult(String num1, String num2) { byte[] left = stringToDigits(num1); byte[] right = stringToDigits(num2); byte[] result = new byte[left.length + right.length]; for (int rightPos = 0; rightPos < right.length; rightPos++) { byte rightDigit = right[rightPos]; byte temp = 0; for (int leftPos = 0; leftPos < left.length; leftPos++) { temp += result[leftPos + rightPos]; temp += rightDigit * left[leftPos]; result[leftPos + rightPos] = (byte) (temp % 10); temp /= 10; } int destPos = rightPos + left.length; while (temp != 0) { temp += result[destPos] & 0xFFFFFFFFL; result[destPos] = (byte) (temp % 10); temp /= 10; destPos++; } } StringBuilder stringResultBuilder = new StringBuilder(result.length); for (int i = result.length - 1; i >= 0; i--) { byte digit = result[i]; if (digit != 0 || stringResultBuilder.length() > 0) { stringResultBuilder.append((char) (digit + '0')); } } return stringResultBuilder.toString(); } public static void main(String[] args) { System.out.println(longMult("18446744073709551616", "18446744073709551616")); } }
Write the same algorithm in Java as shown in this Go implementation.
package main import ( "fmt" "math/big" ) var big1 = new(big.Int).SetUint64(1) func solvePell(nn uint64) (*big.Int, *big.Int) { n := new(big.Int).SetUint64(nn) x := new(big.Int).Set(n) x.Sqrt(x) y := new(big.Int).Set(x) z := new(big.Int).SetUint64(1) r := new(big.Int).Lsh(x, 1) e1 := new(big.Int).SetUint64(1) e2 := new(big.Int) f1 := new(big.Int) f2 := new(big.Int).SetUint64(1) t := new(big.Int) u := new(big.Int) a := new(big.Int) b := new(big.Int) for { t.Mul(r, z) y.Sub(t, y) t.Mul(y, y) t.Sub(n, t) z.Quo(t, z) t.Add(x, y) r.Quo(t, z) u.Set(e1) e1.Set(e2) t.Mul(r, e2) e2.Add(t, u) u.Set(f1) f1.Set(f2) t.Mul(r, f2) f2.Add(t, u) t.Mul(x, f2) a.Add(e2, t) b.Set(f2) t.Mul(a, a) u.Mul(n, b) u.Mul(u, b) t.Sub(t, u) if t.Cmp(big1) == 0 { return a, b } } } func main() { ns := []uint64{61, 109, 181, 277} for _, n := range ns { x, y := solvePell(n) fmt.Printf("x^2 - %3d*y^2 = 1 for x = %-21s and y = %s\n", n, x, y) } }
import java.math.BigInteger; import java.text.NumberFormat; import java.util.ArrayList; import java.util.List; public class PellsEquation { public static void main(String[] args) { NumberFormat format = NumberFormat.getInstance(); for ( int n : new int[] {61, 109, 181, 277, 8941} ) { BigInteger[] pell = pellsEquation(n); System.out.printf("x^2 - %3d * y^2 = 1 for:%n x = %s%n y = %s%n%n", n, format.format(pell[0]), format.format(pell[1])); } } private static final BigInteger[] pellsEquation(int n) { int a0 = (int) Math.sqrt(n); if ( a0*a0 == n ) { throw new IllegalArgumentException("ERROR 102: Invalid n = " + n); } List<Integer> continuedFrac = continuedFraction(n); int count = 0; BigInteger ajm2 = BigInteger.ONE; BigInteger ajm1 = new BigInteger(a0 + ""); BigInteger bjm2 = BigInteger.ZERO; BigInteger bjm1 = BigInteger.ONE; boolean stop = (continuedFrac.size() % 2 == 1); if ( continuedFrac.size() == 2 ) { stop = true; } while ( true ) { count++; BigInteger bn = new BigInteger(continuedFrac.get(count) + ""); BigInteger aj = bn.multiply(ajm1).add(ajm2); BigInteger bj = bn.multiply(bjm1).add(bjm2); if ( stop && (count == continuedFrac.size()-2 || continuedFrac.size() == 2) ) { return new BigInteger[] {aj, bj}; } else if (continuedFrac.size() % 2 == 0 && count == continuedFrac.size()-2 ) { stop = true; } if ( count == continuedFrac.size()-1 ) { count = 0; } ajm2 = ajm1; ajm1 = aj; bjm2 = bjm1; bjm1 = bj; } } private static final List<Integer> continuedFraction(int n) { List<Integer> answer = new ArrayList<Integer>(); int a0 = (int) Math.sqrt(n); answer.add(a0); int a = -a0; int aStart = a; int b = 1; int bStart = b; while ( true ) { int[] values = iterateFrac(n, a, b); answer.add(values[0]); a = values[1]; b = values[2]; if (a == aStart && b == bStart) break; } return answer; } private static final int[] iterateFrac(int n, int a, int b) { int x = (int) Math.floor((b * Math.sqrt(n) - b * a)/(n - a * a)); int[] answer = new int[3]; answer[0] = x; answer[1] = -(b * a + x *(n - a * a)) / b; answer[2] = (n - a * a) / b; return answer; } }
Translate the given Go code snippet into Java without altering its behavior.
package main import ( "bufio" "bytes" "fmt" "math/rand" "os" "strings" "time" ) func main() { fmt.Println(`Cows and Bulls Guess four digit number of unique digits in the range 1 to 9. A correct digit but not in the correct place is a cow. A correct digit in the correct place is a bull.`) pat := make([]byte, 4) rand.Seed(time.Now().Unix()) r := rand.Perm(9) for i := range pat { pat[i] = '1' + byte(r[i]) } valid := []byte("123456789") guess: for in := bufio.NewReader(os.Stdin); ; { fmt.Print("Guess: ") guess, err := in.ReadString('\n') if err != nil { fmt.Println("\nSo, bye.") return } guess = strings.TrimSpace(guess) if len(guess) != 4 { fmt.Println("Please guess a four digit number.") continue } var cows, bulls int for ig, cg := range guess { if strings.IndexRune(guess[:ig], cg) >= 0 { fmt.Printf("Repeated digit: %c\n", cg) continue guess } switch bytes.IndexByte(pat, byte(cg)) { case -1: if bytes.IndexByte(valid, byte(cg)) == -1 { fmt.Printf("Invalid digit: %c\n", cg) continue guess } default: cows++ case ig: bulls++ } } fmt.Printf("Cows: %d, bulls: %d\n", cows, bulls) if bulls == 4 { fmt.Println("You got it.") return } } }
import java.util.InputMismatchException; import java.util.Random; import java.util.Scanner; public class BullsAndCows{ public static void main(String[] args){ Random gen= new Random(); int target; while(hasDupes(target= (gen.nextInt(9000) + 1000))); String targetStr = target +""; boolean guessed = false; Scanner input = new Scanner(System.in); int guesses = 0; do{ int bulls = 0; int cows = 0; System.out.print("Guess a 4-digit number with no duplicate digits: "); int guess; try{ guess = input.nextInt(); if(hasDupes(guess) || guess < 1000) continue; }catch(InputMismatchException e){ continue; } guesses++; String guessStr = guess + ""; for(int i= 0;i < 4;i++){ if(guessStr.charAt(i) == targetStr.charAt(i)){ bulls++; }else if(targetStr.contains(guessStr.charAt(i)+"")){ cows++; } } if(bulls == 4){ guessed = true; }else{ System.out.println(cows+" Cows and "+bulls+" Bulls."); } }while(!guessed); System.out.println("You won after "+guesses+" guesses!"); } public static boolean hasDupes(int num){ boolean[] digs = new boolean[10]; while(num > 0){ if(digs[num%10]) return true; digs[num%10] = true; num/= 10; } return false; } }
Ensure the translated Java code behaves exactly like the original Go snippet.
package main import "fmt" func main() { list := []int{31, 41, 59, 26, 53, 58, 97, 93, 23, 84} fmt.Println("unsorted:", list) bubblesort(list) fmt.Println("sorted! ", list) } func bubblesort(a []int) { for itemCount := len(a) - 1; ; itemCount-- { hasChanged := false for index := 0; index < itemCount; index++ { if a[index] > a[index+1] { a[index], a[index+1] = a[index+1], a[index] hasChanged = true } } if hasChanged == false { break } } }
public static <E extends Comparable<? super E>> void bubbleSort(E[] comparable) { boolean changed = false; do { changed = false; for (int a = 0; a < comparable.length - 1; a++) { if (comparable[a].compareTo(comparable[a + 1]) > 0) { E tmp = comparable[a]; comparable[a] = comparable[a + 1]; comparable[a + 1] = tmp; changed = true; } } } while (changed); }
Keep all operations the same but rewrite the snippet in Java.
package main import "fmt" func prodDivisors(n int) int { prod := 1 i := 1 k := 2 if n%2 == 0 { k = 1 } for i*i <= n { if n%i == 0 { prod *= i j := n / i if j != i { prod *= j } } i += k } return prod } func main() { fmt.Println("The products of positive divisors for the first 50 positive integers are:") for i := 1; i <= 50; i++ { fmt.Printf("%9d ", prodDivisors(i)) if i%5 == 0 { fmt.Println() } } }
public class ProductOfDivisors { private static long divisorCount(long n) { long total = 1; for (; (n & 1) == 0; n >>= 1) { ++total; } for (long p = 3; p * p <= n; p += 2) { long count = 1; for (; n % p == 0; n /= p) { ++count; } total *= count; } if (n > 1) { total *= 2; } return total; } private static long divisorProduct(long n) { return (long) Math.pow(n, divisorCount(n) / 2.0); } public static void main(String[] args) { final long limit = 50; System.out.printf("Product of divisors for the first %d positive integers:%n", limit); for (long n = 1; n <= limit; n++) { System.out.printf("%11d", divisorProduct(n)); if (n % 5 == 0) { System.out.println(); } } } }
Please provide an equivalent version of this Go code in Java.
package main import "fmt" func prodDivisors(n int) int { prod := 1 i := 1 k := 2 if n%2 == 0 { k = 1 } for i*i <= n { if n%i == 0 { prod *= i j := n / i if j != i { prod *= j } } i += k } return prod } func main() { fmt.Println("The products of positive divisors for the first 50 positive integers are:") for i := 1; i <= 50; i++ { fmt.Printf("%9d ", prodDivisors(i)) if i%5 == 0 { fmt.Println() } } }
public class ProductOfDivisors { private static long divisorCount(long n) { long total = 1; for (; (n & 1) == 0; n >>= 1) { ++total; } for (long p = 3; p * p <= n; p += 2) { long count = 1; for (; n % p == 0; n /= p) { ++count; } total *= count; } if (n > 1) { total *= 2; } return total; } private static long divisorProduct(long n) { return (long) Math.pow(n, divisorCount(n) / 2.0); } public static void main(String[] args) { final long limit = 50; System.out.printf("Product of divisors for the first %d positive integers:%n", limit); for (long n = 1; n <= limit; n++) { System.out.printf("%11d", divisorProduct(n)); if (n % 5 == 0) { System.out.println(); } } } }
Please provide an equivalent version of this Go code in Java.
package main import "fmt" func prodDivisors(n int) int { prod := 1 i := 1 k := 2 if n%2 == 0 { k = 1 } for i*i <= n { if n%i == 0 { prod *= i j := n / i if j != i { prod *= j } } i += k } return prod } func main() { fmt.Println("The products of positive divisors for the first 50 positive integers are:") for i := 1; i <= 50; i++ { fmt.Printf("%9d ", prodDivisors(i)) if i%5 == 0 { fmt.Println() } } }
public class ProductOfDivisors { private static long divisorCount(long n) { long total = 1; for (; (n & 1) == 0; n >>= 1) { ++total; } for (long p = 3; p * p <= n; p += 2) { long count = 1; for (; n % p == 0; n /= p) { ++count; } total *= count; } if (n > 1) { total *= 2; } return total; } private static long divisorProduct(long n) { return (long) Math.pow(n, divisorCount(n) / 2.0); } public static void main(String[] args) { final long limit = 50; System.out.printf("Product of divisors for the first %d positive integers:%n", limit); for (long n = 1; n <= limit; n++) { System.out.printf("%11d", divisorProduct(n)); if (n % 5 == 0) { System.out.println(); } } } }
Produce a functionally identical Java code for the snippet given in Go.
package main import ( "fmt" "io/ioutil" ) func main() { b, err := ioutil.ReadFile("input.txt") if err != nil { fmt.Println(err) return } if err = ioutil.WriteFile("output.txt", b, 0666); err != nil { fmt.Println(err) } }
import java.io.*; public class FileIODemo { public static void main(String[] args) { try { FileInputStream in = new FileInputStream("input.txt"); FileOutputStream out = new FileOutputStream("ouput.txt"); int c; while ((c = in.read()) != -1) { out.write(c); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e){ e.printStackTrace(); } } }
Write a version of this Go function in Java with identical behavior.
package main import "fmt" func main() { var a, b int fmt.Print("enter two integers: ") fmt.Scanln(&a, &b) fmt.Printf("%d + %d = %d\n", a, b, a+b) fmt.Printf("%d - %d = %d\n", a, b, a-b) fmt.Printf("%d * %d = %d\n", a, b, a*b) fmt.Printf("%d / %d = %d\n", a, b, a/b) fmt.Printf("%d %% %d = %d\n", a, b, a%b) }
import java.util.Scanner; public class IntegerArithmetic { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int a = sc.nextInt(); int b = sc.nextInt(); int sum = a + b; int difference = a - b; int product = a * b; int division = a / b; int remainder = a % b; System.out.println("a + b = " + sum); System.out.println("a - b = " + difference); System.out.println("a * b = " + product); System.out.println("quotient of a / b = " + division); System.out.println("remainder of a / b = " + remainder); } }
Translate the given Go code snippet into Java without altering its behavior.
package main import ( "fmt" "gonum.org/v1/gonum/mat" ) func main() { m := mat.NewDense(2, 3, []float64{ 1, 2, 3, 4, 5, 6, }) fmt.Println(mat.Formatted(m)) fmt.Println() fmt.Println(mat.Formatted(m.T())) }
import java.util.Arrays; public class Transpose{ public static void main(String[] args){ double[][] m = {{1, 1, 1, 1}, {2, 4, 8, 16}, {3, 9, 27, 81}, {4, 16, 64, 256}, {5, 25, 125, 625}}; double[][] ans = new double[m[0].length][m.length]; for(int rows = 0; rows < m.length; rows++){ for(int cols = 0; cols < m[0].length; cols++){ ans[cols][rows] = m[rows][cols]; } } for(double[] i:ans){ System.out.println(Arrays.toString(i)); } } }
Can you help me rewrite this code in Java instead of Go, keeping it the same logically?
package main import ( "fmt" "gonum.org/v1/gonum/mat" ) func main() { m := mat.NewDense(2, 3, []float64{ 1, 2, 3, 4, 5, 6, }) fmt.Println(mat.Formatted(m)) fmt.Println() fmt.Println(mat.Formatted(m.T())) }
import java.util.Arrays; public class Transpose{ public static void main(String[] args){ double[][] m = {{1, 1, 1, 1}, {2, 4, 8, 16}, {3, 9, 27, 81}, {4, 16, 64, 256}, {5, 25, 125, 625}}; double[][] ans = new double[m[0].length][m.length]; for(int rows = 0; rows < m.length; rows++){ for(int cols = 0; cols < m[0].length; cols++){ ans[cols][rows] = m[rows][cols]; } } for(double[] i:ans){ System.out.println(Arrays.toString(i)); } } }
Keep all operations the same but rewrite the snippet in Java.
package main import "fmt" func a(k int, x1, x2, x3, x4, x5 func() int) int { var b func() int b = func() int { k-- return a(k, b, x1, x2, x3, x4) } if k <= 0 { return x4() + x5() } return b() } func main() { x := func(i int) func() int { return func() int { return i } } fmt.Println(a(10, x(1), x(-1), x(-1), x(1), x(0))) }
import java.util.function.DoubleSupplier; public class ManOrBoy { static double A(int k, DoubleSupplier x1, DoubleSupplier x2, DoubleSupplier x3, DoubleSupplier x4, DoubleSupplier x5) { DoubleSupplier B = new DoubleSupplier() { int m = k; public double getAsDouble() { return A(--m, this, x1, x2, x3, x4); } }; return k <= 0 ? x4.getAsDouble() + x5.getAsDouble() : B.getAsDouble(); } public static void main(String[] args) { System.out.println(A(10, () -> 1.0, () -> -1.0, () -> -1.0, () -> 1.0, () -> 0.0)); } }
Write a version of this Go function in Java with identical behavior.
package main import "fmt" func a(v bool) bool { fmt.Print("a") return v } func b(v bool) bool { fmt.Print("b") return v } func test(i, j bool) { fmt.Printf("Testing a(%t) && b(%t)\n", i, j) fmt.Print("Trace: ") fmt.Println("\nResult:", a(i) && b(j)) fmt.Printf("Testing a(%t) || b(%t)\n", i, j) fmt.Print("Trace: ") fmt.Println("\nResult:", a(i) || b(j)) fmt.Println("") } func main() { test(false, false) test(false, true) test(true, false) test(true, true) }
module test { @Inject Console console; static Boolean show(String name, Boolean value) { console.print($"{name}()={value}"); return value; } void run() { val a = show("a", _); val b = show("b", _); for (Boolean v1 : False..True) { for (Boolean v2 : False..True) { console.print($"a({v1}) && b({v2}) == {a(v1) && b(v2)}"); console.print(); console.print($"a({v1}) || b({v2}) == {a(v1) || b(v2)}"); console.print(); } } } }
Keep all operations the same but rewrite the snippet in Java.
package main import ( "flag" "fmt" "runtime/debug" ) func main() { stack := flag.Int("stack", 0, "maximum per goroutine stack size or 0 for the default") flag.Parse() if *stack > 0 { debug.SetMaxStack(*stack) } r(1) } func r(l int) { if l%1000 == 0 { fmt.Println(l) } r(l + 1) }
public class RecursionTest { private static void recurse(int i) { try { recurse(i+1); } catch (StackOverflowError e) { System.out.print("Recursion depth on this system is " + i + "."); } } public static void main(String[] args) { recurse(0); } }
Can you help me rewrite this code in Java instead of Go, keeping it the same logically?
package main import ( "flag" "fmt" "runtime/debug" ) func main() { stack := flag.Int("stack", 0, "maximum per goroutine stack size or 0 for the default") flag.Parse() if *stack > 0 { debug.SetMaxStack(*stack) } r(1) } func r(l int) { if l%1000 == 0 { fmt.Println(l) } r(l + 1) }
public class RecursionTest { private static void recurse(int i) { try { recurse(i+1); } catch (StackOverflowError e) { System.out.print("Recursion depth on this system is " + i + "."); } } public static void main(String[] args) { recurse(0); } }
Generate a Java translation of this Go snippet without changing its computational steps.
package main import ( "flag" "fmt" "runtime/debug" ) func main() { stack := flag.Int("stack", 0, "maximum per goroutine stack size or 0 for the default") flag.Parse() if *stack > 0 { debug.SetMaxStack(*stack) } r(1) } func r(l int) { if l%1000 == 0 { fmt.Println(l) } r(l + 1) }
public class RecursionTest { private static void recurse(int i) { try { recurse(i+1); } catch (StackOverflowError e) { System.out.print("Recursion depth on this system is " + i + "."); } } public static void main(String[] args) { recurse(0); } }
Rewrite the snippet below in Java so it works the same as the original Go code.
package main import "fmt" func mod(n, m int) int { return ((n % m) + m) % m } func isPrime(n int) bool { if n < 2 { return false } if n % 2 == 0 { return n == 2 } if n % 3 == 0 { return n == 3 } d := 5 for d * d <= n { if n % d == 0 { return false } d += 2 if n % d == 0 { return false } d += 4 } return true } func carmichael(p1 int) { for h3 := 2; h3 < p1; h3++ { for d := 1; d < h3 + p1; d++ { if (h3 + p1) * (p1 - 1) % d == 0 && mod(-p1 * p1, h3) == d % h3 { p2 := 1 + (p1 - 1) * (h3 + p1) / d if !isPrime(p2) { continue } p3 := 1 + p1 * p2 / h3 if !isPrime(p3) { continue } if p2 * p3 % (p1 - 1) != 1 { continue } c := p1 * p2 * p3 fmt.Printf("%2d %4d %5d %d\n", p1, p2, p3, c) } } } } func main() { fmt.Println("The following are Carmichael munbers for p1 <= 61:\n") fmt.Println("p1 p2 p3 product") fmt.Println("== == == =======") for p1 := 2; p1 <= 61; p1++ { if isPrime(p1) { carmichael(p1) } } }
public class Test { static int mod(int n, int m) { return ((n % m) + m) % m; } static boolean isPrime(int n) { if (n == 2 || n == 3) return true; else if (n < 2 || n % 2 == 0 || n % 3 == 0) return false; for (int div = 5, inc = 2; Math.pow(div, 2) <= n; div += inc, inc = 6 - inc) if (n % div == 0) return false; return true; } public static void main(String[] args) { for (int p = 2; p < 62; p++) { if (!isPrime(p)) continue; for (int h3 = 2; h3 < p; h3++) { int g = h3 + p; for (int d = 1; d < g; d++) { if ((g * (p - 1)) % d != 0 || mod(-p * p, h3) != d % h3) continue; int q = 1 + (p - 1) * g / d; if (!isPrime(q)) continue; int r = 1 + (p * q / h3); if (!isPrime(r) || (q * r) % (p - 1) != 1) continue; System.out.printf("%d x %d x %d%n", p, q, r); } } } } }
Change the programming language of this snippet from Go to Java without modifying what it does.
package main import ( "code.google.com/p/x-go-binding/ui/x11" "fmt" "image" "image/color" "image/draw" "log" "os" "time" ) var randcol = genrandcol() func genrandcol() <-chan color.Color { c := make(chan color.Color) go func() { for { select { case c <- image.Black: case c <- image.White: } } }() return c } func gennoise(screen draw.Image) { for y := 0; y < 240; y++ { for x := 0; x < 320; x++ { screen.Set(x, y, <-randcol) } } } func fps() chan<- bool { up := make(chan bool) go func() { var frames int64 var lasttime time.Time var totaltime time.Duration for { <-up frames++ now := time.Now() totaltime += now.Sub(lasttime) if totaltime > time.Second { fmt.Printf("FPS: %v\n", float64(frames)/totaltime.Seconds()) frames = 0 totaltime = 0 } lasttime = now } }() return up } func main() { win, err := x11.NewWindow() if err != nil { fmt.Println(err) os.Exit(1) } defer win.Close() go func() { upfps := fps() screen := win.Screen() for { gennoise(screen) win.FlushImage() upfps <- true } }() for _ = range win.EventChan() { } }
import java.awt.*; import java.awt.event.*; import java.awt.image.*; import java.util.Arrays; import java.util.Random; import javax.swing.*; public class ImageNoise { int framecount = 0; int fps = 0; BufferedImage image; Kernel kernel; ConvolveOp cop; JFrame frame = new JFrame("Java Image Noise"); JPanel panel = new JPanel() { private int show_fps = 0; private MouseAdapter ma = new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { show_fps = (show_fps + 1) % 3; } }; {addMouseListener(ma);} @Override public Dimension getPreferredSize() { return new Dimension(320, 240); } @Override @SuppressWarnings("fallthrough") public void paintComponent(Graphics g1) { Graphics2D g = (Graphics2D) g1; drawNoise(); g.drawImage(image, 0, 0, null); switch (show_fps) { case 0: int xblur = getWidth() - 130, yblur = getHeight() - 32; BufferedImage bc = image.getSubimage(xblur, yblur, 115, 32); BufferedImage bs = new BufferedImage(bc.getWidth(), bc.getHeight(), BufferedImage.TYPE_BYTE_GRAY); cop.filter(bc, bs); g.drawImage(bs, xblur, yblur , null); case 1: g.setColor(Color.RED); g.setFont(new Font("Monospaced", Font.BOLD, 20)); g.drawString("FPS: " + fps, getWidth() - 120, getHeight() - 10); } framecount++; } }; Timer repainter = new Timer(1, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { panel.repaint(); } }); Timer framerateChecker = new Timer(1000, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { fps = framecount; framecount = 0; } }); public ImageNoise() { float[] vals = new float[121]; Arrays.fill(vals, 1/121f); kernel = new Kernel(11, 11, vals); cop = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null); frame.add(panel); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.pack(); frame.setVisible(true); repainter.start(); framerateChecker.start(); } void drawNoise() { int w = panel.getWidth(), h = panel.getHeight(); if (null == image || image.getWidth() != w || image.getHeight() != h) { image = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY); } Random rand = new Random(); int[] data = new int[w * h]; for (int x = 0; x < w * h / 32; x++) { int r = rand.nextInt(); for (int i = 0; i < 32; i++) { data[x * 32 + i] = (r & 1) * Integer.MAX_VALUE; r >>>= 1; } } image.getRaster().setPixels(0, 0, w, h, data); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { ImageNoise i = new ImageNoise(); } }); } }
Write a version of this Go function in Java with identical behavior.
package main import ( "code.google.com/p/x-go-binding/ui/x11" "fmt" "image" "image/color" "image/draw" "log" "os" "time" ) var randcol = genrandcol() func genrandcol() <-chan color.Color { c := make(chan color.Color) go func() { for { select { case c <- image.Black: case c <- image.White: } } }() return c } func gennoise(screen draw.Image) { for y := 0; y < 240; y++ { for x := 0; x < 320; x++ { screen.Set(x, y, <-randcol) } } } func fps() chan<- bool { up := make(chan bool) go func() { var frames int64 var lasttime time.Time var totaltime time.Duration for { <-up frames++ now := time.Now() totaltime += now.Sub(lasttime) if totaltime > time.Second { fmt.Printf("FPS: %v\n", float64(frames)/totaltime.Seconds()) frames = 0 totaltime = 0 } lasttime = now } }() return up } func main() { win, err := x11.NewWindow() if err != nil { fmt.Println(err) os.Exit(1) } defer win.Close() go func() { upfps := fps() screen := win.Screen() for { gennoise(screen) win.FlushImage() upfps <- true } }() for _ = range win.EventChan() { } }
import java.awt.*; import java.awt.event.*; import java.awt.image.*; import java.util.Arrays; import java.util.Random; import javax.swing.*; public class ImageNoise { int framecount = 0; int fps = 0; BufferedImage image; Kernel kernel; ConvolveOp cop; JFrame frame = new JFrame("Java Image Noise"); JPanel panel = new JPanel() { private int show_fps = 0; private MouseAdapter ma = new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { show_fps = (show_fps + 1) % 3; } }; {addMouseListener(ma);} @Override public Dimension getPreferredSize() { return new Dimension(320, 240); } @Override @SuppressWarnings("fallthrough") public void paintComponent(Graphics g1) { Graphics2D g = (Graphics2D) g1; drawNoise(); g.drawImage(image, 0, 0, null); switch (show_fps) { case 0: int xblur = getWidth() - 130, yblur = getHeight() - 32; BufferedImage bc = image.getSubimage(xblur, yblur, 115, 32); BufferedImage bs = new BufferedImage(bc.getWidth(), bc.getHeight(), BufferedImage.TYPE_BYTE_GRAY); cop.filter(bc, bs); g.drawImage(bs, xblur, yblur , null); case 1: g.setColor(Color.RED); g.setFont(new Font("Monospaced", Font.BOLD, 20)); g.drawString("FPS: " + fps, getWidth() - 120, getHeight() - 10); } framecount++; } }; Timer repainter = new Timer(1, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { panel.repaint(); } }); Timer framerateChecker = new Timer(1000, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { fps = framecount; framecount = 0; } }); public ImageNoise() { float[] vals = new float[121]; Arrays.fill(vals, 1/121f); kernel = new Kernel(11, 11, vals); cop = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null); frame.add(panel); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.pack(); frame.setVisible(true); repainter.start(); framerateChecker.start(); } void drawNoise() { int w = panel.getWidth(), h = panel.getHeight(); if (null == image || image.getWidth() != w || image.getHeight() != h) { image = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY); } Random rand = new Random(); int[] data = new int[w * h]; for (int x = 0; x < w * h / 32; x++) { int r = rand.nextInt(); for (int i = 0; i < 32; i++) { data[x * 32 + i] = (r & 1) * Integer.MAX_VALUE; r >>>= 1; } } image.getRaster().setPixels(0, 0, w, h, data); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { ImageNoise i = new ImageNoise(); } }); } }
Generate an equivalent Java version of this Go code.
package main import "fmt" func computePerfect(n int64) bool { var sum int64 for i := int64(1); i < n; i++ { if n%i == 0 { sum += i } } return sum == n } func isPerfect(n int64) bool { switch n { case 6, 28, 496, 8128, 33550336, 8589869056, 137438691328, 2305843008139952128: return true } return false } func main() { for n := int64(1); ; n++ { if isPerfect(n) != computePerfect(n) { panic("bug") } if n%1e3 == 0 { fmt.Println("tested", n) } } }
public static boolean perf(int n){ int sum= 0; for(int i= 1;i < n;i++){ if(n % i == 0){ sum+= i; } } return sum == n; }
Write the same code in Java as shown below in Go.
package main import ( "fmt" "sync" ) var a = []int{170, 45, 75, 90, 802, 24, 2, 66} var aMax = 1000 const bead = 'o' func main() { fmt.Println("before:", a) beadSort() fmt.Println("after: ", a) } func beadSort() { all := make([]byte, aMax*len(a)) abacus := make([][]byte, aMax) for pole, space := 0, all; pole < aMax; pole++ { abacus[pole] = space[:len(a)] space = space[len(a):] } var wg sync.WaitGroup wg.Add(len(a)) for row, n := range a { go func(row, n int) { for pole := 0; pole < n; pole++ { abacus[pole][row] = bead } wg.Done() }(row, n) } wg.Wait() wg.Add(aMax) for _, pole := range abacus { go func(pole []byte) { top := 0 for row, space := range pole { if space == bead { pole[row] = 0 pole[top] = bead top++ } } wg.Done() }(pole) } wg.Wait() for row := range a { x := 0 for pole := 0; pole < aMax && abacus[pole][row] == bead; pole++ { x++ } a[len(a)-1-row] = x } }
public class BeadSort { public static void main(String[] args) { BeadSort now=new BeadSort(); int[] arr=new int[(int)(Math.random()*11)+5]; for(int i=0;i<arr.length;i++) arr[i]=(int)(Math.random()*10); System.out.print("Unsorted: "); now.display1D(arr); int[] sort=now.beadSort(arr); System.out.print("Sorted: "); now.display1D(sort); } int[] beadSort(int[] arr) { int max=a[0]; for(int i=1;i<arr.length;i++) if(arr[i]>max) max=arr[i]; char[][] grid=new char[arr.length][max]; int[] levelcount=new int[max]; for(int i=0;i<max;i++) { levelcount[i]=0; for(int j=0;j<arr.length;j++) grid[j][i]='_'; } for(int i=0;i<arr.length;i++) { int num=arr[i]; for(int j=0;num>0;j++) { grid[levelcount[j]++][j]='*'; num--; } } System.out.println(); display2D(grid); int[] sorted=new int[arr.length]; for(int i=0;i<arr.length;i++) { int putt=0; for(int j=0;j<max&&grid[arr.length-1-i][j]=='*';j++) putt++; sorted[i]=putt; } return sorted; } void display1D(int[] arr) { for(int i=0;i<arr.length;i++) System.out.print(arr[i]+" "); System.out.println(); } void display1D(char[] arr) { for(int i=0;i<arr.length;i++) System.out.print(arr[i]+" "); System.out.println(); } void display2D(char[][] arr) { for(int i=0;i<arr.length;i++) display1D(arr[i]); System.out.println(); } }
Rewrite the snippet below in Java so it works the same as the original Go code.
package main import "fmt" var n = make([][]string, 15) func initN() { for i := 0; i < 15; i++ { n[i] = make([]string, 11) for j := 0; j < 11; j++ { n[i][j] = " " } n[i][5] = "x" } } func horiz(c1, c2, r int) { for c := c1; c <= c2; c++ { n[r][c] = "x" } } func verti(r1, r2, c int) { for r := r1; r <= r2; r++ { n[r][c] = "x" } } func diagd(c1, c2, r int) { for c := c1; c <= c2; c++ { n[r+c-c1][c] = "x" } } func diagu(c1, c2, r int) { for c := c1; c <= c2; c++ { n[r-c+c1][c] = "x" } } var draw map[int]func() func initDraw() { draw = map[int]func(){ 1: func() { horiz(6, 10, 0) }, 2: func() { horiz(6, 10, 4) }, 3: func() { diagd(6, 10, 0) }, 4: func() { diagu(6, 10, 4) }, 5: func() { draw[1](); draw[4]() }, 6: func() { verti(0, 4, 10) }, 7: func() { draw[1](); draw[6]() }, 8: func() { draw[2](); draw[6]() }, 9: func() { draw[1](); draw[8]() }, 10: func() { horiz(0, 4, 0) }, 20: func() { horiz(0, 4, 4) }, 30: func() { diagu(0, 4, 4) }, 40: func() { diagd(0, 4, 0) }, 50: func() { draw[10](); draw[40]() }, 60: func() { verti(0, 4, 0) }, 70: func() { draw[10](); draw[60]() }, 80: func() { draw[20](); draw[60]() }, 90: func() { draw[10](); draw[80]() }, 100: func() { horiz(6, 10, 14) }, 200: func() { horiz(6, 10, 10) }, 300: func() { diagu(6, 10, 14) }, 400: func() { diagd(6, 10, 10) }, 500: func() { draw[100](); draw[400]() }, 600: func() { verti(10, 14, 10) }, 700: func() { draw[100](); draw[600]() }, 800: func() { draw[200](); draw[600]() }, 900: func() { draw[100](); draw[800]() }, 1000: func() { horiz(0, 4, 14) }, 2000: func() { horiz(0, 4, 10) }, 3000: func() { diagd(0, 4, 10) }, 4000: func() { diagu(0, 4, 14) }, 5000: func() { draw[1000](); draw[4000]() }, 6000: func() { verti(10, 14, 0) }, 7000: func() { draw[1000](); draw[6000]() }, 8000: func() { draw[2000](); draw[6000]() }, 9000: func() { draw[1000](); draw[8000]() }, } } func printNumeral() { for i := 0; i < 15; i++ { for j := 0; j < 11; j++ { fmt.Printf("%s ", n[i][j]) } fmt.Println() } fmt.Println() } func main() { initDraw() numbers := []int{0, 1, 20, 300, 4000, 5555, 6789, 9999} for _, number := range numbers { initN() fmt.Printf("%d:\n", number) thousands := number / 1000 number %= 1000 hundreds := number / 100 number %= 100 tens := number / 10 ones := number % 10 if thousands > 0 { draw[thousands*1000]() } if hundreds > 0 { draw[hundreds*100]() } if tens > 0 { draw[tens*10]() } if ones > 0 { draw[ones]() } printNumeral() } }
import java.util.Arrays; import java.util.List; public class Cistercian { private static final int SIZE = 15; private final char[][] canvas = new char[SIZE][SIZE]; public Cistercian(int n) { initN(); draw(n); } public void initN() { for (var row : canvas) { Arrays.fill(row, ' '); row[5] = 'x'; } } private void horizontal(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r][c] = 'x'; } } private void vertical(int r1, int r2, int c) { for (int r = r1; r <= r2; r++) { canvas[r][c] = 'x'; } } private void diagd(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r + c - c1][c] = 'x'; } } private void diagu(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r - c + c1][c] = 'x'; } } private void draw(int v) { var thousands = v / 1000; v %= 1000; var hundreds = v / 100; v %= 100; var tens = v / 10; var ones = v % 10; drawPart(1000 * thousands); drawPart(100 * hundreds); drawPart(10 * tens); drawPart(ones); } private void drawPart(int v) { switch (v) { case 1: horizontal(6, 10, 0); break; case 2: horizontal(6, 10, 4); break; case 3: diagd(6, 10, 0); break; case 4: diagu(6, 10, 4); break; case 5: drawPart(1); drawPart(4); break; case 6: vertical(0, 4, 10); break; case 7: drawPart(1); drawPart(6); break; case 8: drawPart(2); drawPart(6); break; case 9: drawPart(1); drawPart(8); break; case 10: horizontal(0, 4, 0); break; case 20: horizontal(0, 4, 4); break; case 30: diagu(0, 4, 4); break; case 40: diagd(0, 4, 0); break; case 50: drawPart(10); drawPart(40); break; case 60: vertical(0, 4, 0); break; case 70: drawPart(10); drawPart(60); break; case 80: drawPart(20); drawPart(60); break; case 90: drawPart(10); drawPart(80); break; case 100: horizontal(6, 10, 14); break; case 200: horizontal(6, 10, 10); break; case 300: diagu(6, 10, 14); break; case 400: diagd(6, 10, 10); break; case 500: drawPart(100); drawPart(400); break; case 600: vertical(10, 14, 10); break; case 700: drawPart(100); drawPart(600); break; case 800: drawPart(200); drawPart(600); break; case 900: drawPart(100); drawPart(800); break; case 1000: horizontal(0, 4, 14); break; case 2000: horizontal(0, 4, 10); break; case 3000: diagd(0, 4, 10); break; case 4000: diagu(0, 4, 14); break; case 5000: drawPart(1000); drawPart(4000); break; case 6000: vertical(10, 14, 0); break; case 7000: drawPart(1000); drawPart(6000); break; case 8000: drawPart(2000); drawPart(6000); break; case 9000: drawPart(1000); drawPart(8000); break; } } @Override public String toString() { StringBuilder builder = new StringBuilder(); for (var row : canvas) { builder.append(row); builder.append('\n'); } return builder.toString(); } public static void main(String[] args) { for (int number : List.of(0, 1, 20, 300, 4000, 5555, 6789, 9999)) { System.out.printf("%d:\n", number); var c = new Cistercian(number); System.out.println(c); } } }
Port the following code from Go to Java with equivalent syntax and logic.
package main import "fmt" var n = make([][]string, 15) func initN() { for i := 0; i < 15; i++ { n[i] = make([]string, 11) for j := 0; j < 11; j++ { n[i][j] = " " } n[i][5] = "x" } } func horiz(c1, c2, r int) { for c := c1; c <= c2; c++ { n[r][c] = "x" } } func verti(r1, r2, c int) { for r := r1; r <= r2; r++ { n[r][c] = "x" } } func diagd(c1, c2, r int) { for c := c1; c <= c2; c++ { n[r+c-c1][c] = "x" } } func diagu(c1, c2, r int) { for c := c1; c <= c2; c++ { n[r-c+c1][c] = "x" } } var draw map[int]func() func initDraw() { draw = map[int]func(){ 1: func() { horiz(6, 10, 0) }, 2: func() { horiz(6, 10, 4) }, 3: func() { diagd(6, 10, 0) }, 4: func() { diagu(6, 10, 4) }, 5: func() { draw[1](); draw[4]() }, 6: func() { verti(0, 4, 10) }, 7: func() { draw[1](); draw[6]() }, 8: func() { draw[2](); draw[6]() }, 9: func() { draw[1](); draw[8]() }, 10: func() { horiz(0, 4, 0) }, 20: func() { horiz(0, 4, 4) }, 30: func() { diagu(0, 4, 4) }, 40: func() { diagd(0, 4, 0) }, 50: func() { draw[10](); draw[40]() }, 60: func() { verti(0, 4, 0) }, 70: func() { draw[10](); draw[60]() }, 80: func() { draw[20](); draw[60]() }, 90: func() { draw[10](); draw[80]() }, 100: func() { horiz(6, 10, 14) }, 200: func() { horiz(6, 10, 10) }, 300: func() { diagu(6, 10, 14) }, 400: func() { diagd(6, 10, 10) }, 500: func() { draw[100](); draw[400]() }, 600: func() { verti(10, 14, 10) }, 700: func() { draw[100](); draw[600]() }, 800: func() { draw[200](); draw[600]() }, 900: func() { draw[100](); draw[800]() }, 1000: func() { horiz(0, 4, 14) }, 2000: func() { horiz(0, 4, 10) }, 3000: func() { diagd(0, 4, 10) }, 4000: func() { diagu(0, 4, 14) }, 5000: func() { draw[1000](); draw[4000]() }, 6000: func() { verti(10, 14, 0) }, 7000: func() { draw[1000](); draw[6000]() }, 8000: func() { draw[2000](); draw[6000]() }, 9000: func() { draw[1000](); draw[8000]() }, } } func printNumeral() { for i := 0; i < 15; i++ { for j := 0; j < 11; j++ { fmt.Printf("%s ", n[i][j]) } fmt.Println() } fmt.Println() } func main() { initDraw() numbers := []int{0, 1, 20, 300, 4000, 5555, 6789, 9999} for _, number := range numbers { initN() fmt.Printf("%d:\n", number) thousands := number / 1000 number %= 1000 hundreds := number / 100 number %= 100 tens := number / 10 ones := number % 10 if thousands > 0 { draw[thousands*1000]() } if hundreds > 0 { draw[hundreds*100]() } if tens > 0 { draw[tens*10]() } if ones > 0 { draw[ones]() } printNumeral() } }
import java.util.Arrays; import java.util.List; public class Cistercian { private static final int SIZE = 15; private final char[][] canvas = new char[SIZE][SIZE]; public Cistercian(int n) { initN(); draw(n); } public void initN() { for (var row : canvas) { Arrays.fill(row, ' '); row[5] = 'x'; } } private void horizontal(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r][c] = 'x'; } } private void vertical(int r1, int r2, int c) { for (int r = r1; r <= r2; r++) { canvas[r][c] = 'x'; } } private void diagd(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r + c - c1][c] = 'x'; } } private void diagu(int c1, int c2, int r) { for (int c = c1; c <= c2; c++) { canvas[r - c + c1][c] = 'x'; } } private void draw(int v) { var thousands = v / 1000; v %= 1000; var hundreds = v / 100; v %= 100; var tens = v / 10; var ones = v % 10; drawPart(1000 * thousands); drawPart(100 * hundreds); drawPart(10 * tens); drawPart(ones); } private void drawPart(int v) { switch (v) { case 1: horizontal(6, 10, 0); break; case 2: horizontal(6, 10, 4); break; case 3: diagd(6, 10, 0); break; case 4: diagu(6, 10, 4); break; case 5: drawPart(1); drawPart(4); break; case 6: vertical(0, 4, 10); break; case 7: drawPart(1); drawPart(6); break; case 8: drawPart(2); drawPart(6); break; case 9: drawPart(1); drawPart(8); break; case 10: horizontal(0, 4, 0); break; case 20: horizontal(0, 4, 4); break; case 30: diagu(0, 4, 4); break; case 40: diagd(0, 4, 0); break; case 50: drawPart(10); drawPart(40); break; case 60: vertical(0, 4, 0); break; case 70: drawPart(10); drawPart(60); break; case 80: drawPart(20); drawPart(60); break; case 90: drawPart(10); drawPart(80); break; case 100: horizontal(6, 10, 14); break; case 200: horizontal(6, 10, 10); break; case 300: diagu(6, 10, 14); break; case 400: diagd(6, 10, 10); break; case 500: drawPart(100); drawPart(400); break; case 600: vertical(10, 14, 10); break; case 700: drawPart(100); drawPart(600); break; case 800: drawPart(200); drawPart(600); break; case 900: drawPart(100); drawPart(800); break; case 1000: horizontal(0, 4, 14); break; case 2000: horizontal(0, 4, 10); break; case 3000: diagd(0, 4, 10); break; case 4000: diagu(0, 4, 14); break; case 5000: drawPart(1000); drawPart(4000); break; case 6000: vertical(10, 14, 0); break; case 7000: drawPart(1000); drawPart(6000); break; case 8000: drawPart(2000); drawPart(6000); break; case 9000: drawPart(1000); drawPart(8000); break; } } @Override public String toString() { StringBuilder builder = new StringBuilder(); for (var row : canvas) { builder.append(row); builder.append('\n'); } return builder.toString(); } public static void main(String[] args) { for (int number : List.of(0, 1, 20, 300, 4000, 5555, 6789, 9999)) { System.out.printf("%d:\n", number); var c = new Cistercian(number); System.out.println(c); } } }
Convert this Go snippet to Java and keep its semantics consistent.
package main import ( "fmt" "math/big" ) func main() { x := big.NewInt(2) x = x.Exp(big.NewInt(3), x, nil) x = x.Exp(big.NewInt(4), x, nil) x = x.Exp(big.NewInt(5), x, nil) str := x.String() fmt.Printf("5^(4^(3^2)) has %d digits: %s ... %s\n", len(str), str[:20], str[len(str)-20:], ) }
import java.math.BigInteger; class IntegerPower { public static void main(String[] args) { BigInteger power = BigInteger.valueOf(5).pow(BigInteger.valueOf(4).pow(BigInteger.valueOf(3).pow(2).intValueExact()).intValueExact()); String str = power.toString(); int len = str.length(); System.out.printf("5**4**3**2 = %s...%s and has %d digits%n", str.substring(0, 20), str.substring(len - 20), len); } }
Please provide an equivalent version of this Go code in Java.
package main import ( "fmt" "image" "image/color" "image/png" "math" "os" ) type vector [3]float64 func normalize(v *vector) { invLen := 1 / math.Sqrt(dot(v, v)) v[0] *= invLen v[1] *= invLen v[2] *= invLen } func dot(x, y *vector) float64 { return x[0]*y[0] + x[1]*y[1] + x[2]*y[2] } func drawSphere(r int, k, amb float64, dir *vector) *image.Gray { w, h := r*4, r*3 img := image.NewGray(image.Rect(-w/2, -h/2, w/2, h/2)) vec := new(vector) for x := -r; x < r; x++ { for y := -r; y < r; y++ { if z := r*r - x*x - y*y; z >= 0 { vec[0] = float64(x) vec[1] = float64(y) vec[2] = math.Sqrt(float64(z)) normalize(vec) s := dot(dir, vec) if s < 0 { s = 0 } lum := 255 * (math.Pow(s, k) + amb) / (1 + amb) if lum < 0 { lum = 0 } else if lum > 255 { lum = 255 } img.SetGray(x, y, color.Gray{uint8(lum)}) } } } return img } func main() { dir := &vector{-30, -30, 50} normalize(dir) img := drawSphere(200, 1.5, .2, dir) f, err := os.Create("sphere.png") if err != nil { fmt.Println(err) return } if err = png.Encode(f, img); err != nil { fmt.Println(err) } if err = f.Close(); err != nil { fmt.Println(err) } }
using System; namespace Sphere { internal class Program { private const string Shades = ".:!*oe%&#@"; private static readonly double[] Light = {30, 30, -50}; private static void Normalize(double[] v) { double len = Math.Sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]); v[0] /= len; v[1] /= len; v[2] /= len; } private static double Dot(double[] x, double[] y) { double d = x[0]*y[0] + x[1]*y[1] + x[2]*y[2]; return d < 0 ? -d : 0; } public static void DrawSphere(double r, double k, double ambient) { var vec = new double[3]; for(var i = (int)Math.Floor(-r); i <= (int)Math.Ceiling(r); i++) { double x = i + .5; for(var j = (int)Math.Floor(-2*r); j <= (int)Math.Ceiling(2*r); j++) { double y = j/2.0 + .5; if(x*x + y*y <= r*r) { vec[0] = x; vec[1] = y; vec[2] = Math.Sqrt(r*r - x*x - y*y); Normalize(vec); double b = Math.Pow(Dot(Light, vec), k) + ambient; int intensity = (b <= 0) ? Shades.Length - 2 : (int)Math.Max((1 - b)*(Shades.Length - 1), 0); Console.Write(Shades[intensity]); } else Console.Write(' '); } Console.WriteLine(); } } private static void Main() { Normalize(Light); DrawSphere(6, 4, .1); DrawSphere(10, 2, .4); Console.ReadKey(); } } }
Write a version of this Go function in Java with identical behavior.
package main import ( "fmt" "image" "image/color" "image/png" "math" "os" ) type vector [3]float64 func normalize(v *vector) { invLen := 1 / math.Sqrt(dot(v, v)) v[0] *= invLen v[1] *= invLen v[2] *= invLen } func dot(x, y *vector) float64 { return x[0]*y[0] + x[1]*y[1] + x[2]*y[2] } func drawSphere(r int, k, amb float64, dir *vector) *image.Gray { w, h := r*4, r*3 img := image.NewGray(image.Rect(-w/2, -h/2, w/2, h/2)) vec := new(vector) for x := -r; x < r; x++ { for y := -r; y < r; y++ { if z := r*r - x*x - y*y; z >= 0 { vec[0] = float64(x) vec[1] = float64(y) vec[2] = math.Sqrt(float64(z)) normalize(vec) s := dot(dir, vec) if s < 0 { s = 0 } lum := 255 * (math.Pow(s, k) + amb) / (1 + amb) if lum < 0 { lum = 0 } else if lum > 255 { lum = 255 } img.SetGray(x, y, color.Gray{uint8(lum)}) } } } return img } func main() { dir := &vector{-30, -30, 50} normalize(dir) img := drawSphere(200, 1.5, .2, dir) f, err := os.Create("sphere.png") if err != nil { fmt.Println(err) return } if err = png.Encode(f, img); err != nil { fmt.Println(err) } if err = f.Close(); err != nil { fmt.Println(err) } }
using System; namespace Sphere { internal class Program { private const string Shades = ".:!*oe%&#@"; private static readonly double[] Light = {30, 30, -50}; private static void Normalize(double[] v) { double len = Math.Sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]); v[0] /= len; v[1] /= len; v[2] /= len; } private static double Dot(double[] x, double[] y) { double d = x[0]*y[0] + x[1]*y[1] + x[2]*y[2]; return d < 0 ? -d : 0; } public static void DrawSphere(double r, double k, double ambient) { var vec = new double[3]; for(var i = (int)Math.Floor(-r); i <= (int)Math.Ceiling(r); i++) { double x = i + .5; for(var j = (int)Math.Floor(-2*r); j <= (int)Math.Ceiling(2*r); j++) { double y = j/2.0 + .5; if(x*x + y*y <= r*r) { vec[0] = x; vec[1] = y; vec[2] = Math.Sqrt(r*r - x*x - y*y); Normalize(vec); double b = Math.Pow(Dot(Light, vec), k) + ambient; int intensity = (b <= 0) ? Shades.Length - 2 : (int)Math.Max((1 - b)*(Shades.Length - 1), 0); Console.Write(Shades[intensity]); } else Console.Write(' '); } Console.WriteLine(); } } private static void Main() { Normalize(Light); DrawSphere(6, 4, .1); DrawSphere(10, 2, .4); Console.ReadKey(); } } }
Produce a language-to-language conversion: from Go to Java, same semantics.
package main import ( "bufio" "bytes" "errors" "fmt" "io" "os" ) var index map[string][]int var indexed []doc type doc struct { file string title string } func main() { index = make(map[string][]int) if err := indexDir("docs"); err != nil { fmt.Println(err) return } ui() } func indexDir(dir string) error { df, err := os.Open(dir) if err != nil { return err } fis, err := df.Readdir(-1) if err != nil { return err } if len(fis) == 0 { return errors.New(fmt.Sprintf("no files in %s", dir)) } indexed := 0 for _, fi := range fis { if !fi.IsDir() { if indexFile(dir + "/" + fi.Name()) { indexed++ } } } return nil } func indexFile(fn string) bool { f, err := os.Open(fn) if err != nil { fmt.Println(err) return false } x := len(indexed) indexed = append(indexed, doc{fn, fn}) pdoc := &indexed[x] r := bufio.NewReader(f) lines := 0 for { b, isPrefix, err := r.ReadLine() switch { case err == io.EOF: return true case err != nil: fmt.Println(err) return true case isPrefix: fmt.Printf("%s: unexpected long line\n", fn) return true case lines < 20 && bytes.HasPrefix(b, []byte("Title:")): pdoc.title = string(b[7:]) } wordLoop: for _, bword := range bytes.Fields(b) { bword := bytes.Trim(bword, ".,-~?!\"'`;:()<>[]{}\\|/=_+*&^%$#@") if len(bword) > 0 { word := string(bword) dl := index[word] for _, d := range dl { if d == x { continue wordLoop } } index[word] = append(dl, x) } } } return true } func ui() { fmt.Println(len(index), "words indexed in", len(indexed), "files") fmt.Println("enter single words to search for") fmt.Println("enter a blank line when done") var word string for { fmt.Print("search word: ") wc, _ := fmt.Scanln(&word) if wc == 0 { return } switch dl := index[word]; len(dl) { case 0: fmt.Println("no match") case 1: fmt.Println("one match:") fmt.Println(" ", indexed[dl[0]].file, indexed[dl[0]].title) default: fmt.Println(len(dl), "matches:") for _, d := range dl { fmt.Println(" ", indexed[d].file, indexed[d].title) } } } }
package org.rosettacode; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Set; public class InvertedIndex { List<String> stopwords = Arrays.asList("a", "able", "about", "across", "after", "all", "almost", "also", "am", "among", "an", "and", "any", "are", "as", "at", "be", "because", "been", "but", "by", "can", "cannot", "could", "dear", "did", "do", "does", "either", "else", "ever", "every", "for", "from", "get", "got", "had", "has", "have", "he", "her", "hers", "him", "his", "how", "however", "i", "if", "in", "into", "is", "it", "its", "just", "least", "let", "like", "likely", "may", "me", "might", "most", "must", "my", "neither", "no", "nor", "not", "of", "off", "often", "on", "only", "or", "other", "our", "own", "rather", "said", "say", "says", "she", "should", "since", "so", "some", "than", "that", "the", "their", "them", "then", "there", "these", "they", "this", "tis", "to", "too", "twas", "us", "wants", "was", "we", "were", "what", "when", "where", "which", "while", "who", "whom", "why", "will", "with", "would", "yet", "you", "your"); Map<String, List<Tuple>> index = new HashMap<String, List<Tuple>>(); List<String> files = new ArrayList<String>(); public void indexFile(File file) throws IOException { int fileno = files.indexOf(file.getPath()); if (fileno == -1) { files.add(file.getPath()); fileno = files.size() - 1; } int pos = 0; BufferedReader reader = new BufferedReader(new FileReader(file)); for (String line = reader.readLine(); line != null; line = reader .readLine()) { for (String _word : line.split("\\W+")) { String word = _word.toLowerCase(); pos++; if (stopwords.contains(word)) continue; List<Tuple> idx = index.get(word); if (idx == null) { idx = new LinkedList<Tuple>(); index.put(word, idx); } idx.add(new Tuple(fileno, pos)); } } System.out.println("indexed " + file.getPath() + " " + pos + " words"); } public void search(List<String> words) { for (String _word : words) { Set<String> answer = new HashSet<String>(); String word = _word.toLowerCase(); List<Tuple> idx = index.get(word); if (idx != null) { for (Tuple t : idx) { answer.add(files.get(t.fileno)); } } System.out.print(word); for (String f : answer) { System.out.print(" " + f); } System.out.println(""); } } public static void main(String[] args) { try { InvertedIndex idx = new InvertedIndex(); for (int i = 1; i < args.length; i++) { idx.indexFile(new File(args[i])); } idx.search(Arrays.asList(args[0].split(","))); } catch (Exception e) { e.printStackTrace(); } } private class Tuple { private int fileno; private int position; public Tuple(int fileno, int position) { this.fileno = fileno; this.position = position; } } }
Can you help me rewrite this code in Java instead of Go, keeping it the same logically?
package main import ( "fmt" "math/big" ) var m, n, z big.Int func init() { m.SetString("2562047788015215500854906332309589561", 10) n.SetString("6795454494268282920431565661684282819", 10) } func main() { fmt.Println(z.Mul(z.Div(&m, z.GCD(nil, nil, &m, &n)), &n)) }
import java.util.Scanner; public class LCM{ public static void main(String[] args){ Scanner aScanner = new Scanner(System.in); System.out.print("Enter the value of m:"); int m = aScanner.nextInt(); System.out.print("Enter the value of n:"); int n = aScanner.nextInt(); int lcm = (n == m || n == 1) ? m :(m == 1 ? n : 0); if (lcm == 0) { int mm = m, nn = n; while (mm != nn) { while (mm < nn) { mm += m; } while (nn < mm) { nn += n; } } lcm = mm; } System.out.println("lcm(" + m + ", " + n + ") = " + lcm); } }
Can you help me rewrite this code in Java instead of Go, keeping it the same logically?
package main import ( "fmt" "math/big" ) var m, n, z big.Int func init() { m.SetString("2562047788015215500854906332309589561", 10) n.SetString("6795454494268282920431565661684282819", 10) } func main() { fmt.Println(z.Mul(z.Div(&m, z.GCD(nil, nil, &m, &n)), &n)) }
import java.util.Scanner; public class LCM{ public static void main(String[] args){ Scanner aScanner = new Scanner(System.in); System.out.print("Enter the value of m:"); int m = aScanner.nextInt(); System.out.print("Enter the value of n:"); int n = aScanner.nextInt(); int lcm = (n == m || n == 1) ? m :(m == 1 ? n : 0); if (lcm == 0) { int mm = m, nn = n; while (mm != nn) { while (mm < nn) { mm += m; } while (nn < mm) { nn += n; } } lcm = mm; } System.out.println("lcm(" + m + ", " + n + ") = " + lcm); } }
Port the following code from Go to Java with equivalent syntax and logic.
package main import ( "fmt" "math/big" ) var m, n, z big.Int func init() { m.SetString("2562047788015215500854906332309589561", 10) n.SetString("6795454494268282920431565661684282819", 10) } func main() { fmt.Println(z.Mul(z.Div(&m, z.GCD(nil, nil, &m, &n)), &n)) }
import java.util.Scanner; public class LCM{ public static void main(String[] args){ Scanner aScanner = new Scanner(System.in); System.out.print("Enter the value of m:"); int m = aScanner.nextInt(); System.out.print("Enter the value of n:"); int n = aScanner.nextInt(); int lcm = (n == m || n == 1) ? m :(m == 1 ? n : 0); if (lcm == 0) { int mm = m, nn = n; while (mm != nn) { while (mm < nn) { mm += m; } while (nn < mm) { nn += n; } } lcm = mm; } System.out.println("lcm(" + m + ", " + n + ") = " + lcm); } }
Write the same code in Java as shown below in Go.
package main import "fmt" import "math/rand" import "time" func main() { rand.Seed(time.Now().UnixNano()) for { a := rand.Intn(20) fmt.Println(a) if a == 10 { break } b := rand.Intn(20) fmt.Println(b) } }
import java.util.Random; Random rand = new Random(); while(true){ int a = rand.nextInt(20); System.out.println(a); if(a == 10) break; int b = rand.nextInt(20); System.out.println(b); }
Generate an equivalent Java version of this Go code.
package main import ( "fmt" "os" ) func main() { lp0, err := os.Create("/dev/lp0") if err != nil { panic(err) } defer lp0.Close() fmt.Fprintln(lp0, "Hello World!") }
import java.io.FileWriter; import java.io.IOException; public class LinePrinter { public static void main(String[] args) { try { FileWriter lp0 = new FileWriter("/dev/lp0"); lp0.write("Hello World!"); lp0.close(); } catch (IOException ioe) { ioe.printStackTrace(); } } }
Write the same code in Java as shown below in Go.
package main import ( "fmt" "os" ) func main() { lp0, err := os.Create("/dev/lp0") if err != nil { panic(err) } defer lp0.Close() fmt.Fprintln(lp0, "Hello World!") }
import java.io.FileWriter; import java.io.IOException; public class LinePrinter { public static void main(String[] args) { try { FileWriter lp0 = new FileWriter("/dev/lp0"); lp0.write("Hello World!"); lp0.close(); } catch (IOException ioe) { ioe.printStackTrace(); } } }
Ensure the translated Java code behaves exactly like the original Go snippet.
package main import ( "fmt" "os" ) func main() { lp0, err := os.Create("/dev/lp0") if err != nil { panic(err) } defer lp0.Close() fmt.Fprintln(lp0, "Hello World!") }
import java.io.FileWriter; import java.io.IOException; public class LinePrinter { public static void main(String[] args) { try { FileWriter lp0 = new FileWriter("/dev/lp0"); lp0.write("Hello World!"); lp0.close(); } catch (IOException ioe) { ioe.printStackTrace(); } } }
Convert the following code from Go to Java, ensuring the logic remains intact.
package main import "fmt" func maxl(hm []int ) []int{ res := make([]int,len(hm)) max := 1 for i := 0; i < len(hm);i++{ if(hm[i] > max){ max = hm[i] } res[i] = max; } return res } func maxr(hm []int ) []int{ res := make([]int,len(hm)) max := 1 for i := len(hm) - 1 ; i >= 0;i--{ if(hm[i] > max){ max = hm[i] } res[i] = max; } return res } func min(a,b []int) []int { res := make([]int,len(a)) for i := 0; i < len(a);i++{ if a[i] >= b[i]{ res[i] = b[i] }else { res[i] = a[i] } } return res } func diff(hm, min []int) []int { res := make([]int,len(hm)) for i := 0; i < len(hm);i++{ if min[i] > hm[i]{ res[i] = min[i] - hm[i] } } return res } func sum(a []int) int { res := 0 for i := 0; i < len(a);i++{ res += a[i] } return res } func waterCollected(hm []int) int { maxr := maxr(hm) maxl := maxl(hm) min := min(maxr,maxl) diff := diff(hm,min) sum := sum(diff) return sum } func main() { fmt.Println(waterCollected([]int{1, 5, 3, 7, 2})) fmt.Println(waterCollected([]int{5, 3, 7, 2, 6, 4, 5, 9, 1, 2})) fmt.Println(waterCollected([]int{2, 6, 3, 5, 2, 8, 1, 4, 2, 2, 5, 3, 5, 7, 4, 1})) fmt.Println(waterCollected([]int{5, 5, 5, 5})) fmt.Println(waterCollected([]int{5, 6, 7, 8})) fmt.Println(waterCollected([]int{8, 7, 7, 6})) fmt.Println(waterCollected([]int{6, 7, 10, 7, 6})) }
public class WaterBetweenTowers { public static void main(String[] args) { int i = 1; int[][] tba = new int[][]{ new int[]{1, 5, 3, 7, 2}, new int[]{5, 3, 7, 2, 6, 4, 5, 9, 1, 2}, new int[]{2, 6, 3, 5, 2, 8, 1, 4, 2, 2, 5, 3, 5, 7, 4, 1}, new int[]{5, 5, 5, 5}, new int[]{5, 6, 7, 8}, new int[]{8, 7, 7, 6}, new int[]{6, 7, 10, 7, 6} }; for (int[] tea : tba) { int rht, wu = 0, bof; do { for (rht = tea.length - 1; rht >= 0; rht--) { if (tea[rht] > 0) { break; } } if (rht < 0) { break; } bof = 0; for (int col = 0; col <= rht; col++) { if (tea[col] > 0) { tea[col]--; bof += 1; } else if (bof > 0) { wu++; } } if (bof < 2) { break; } } while (true); System.out.printf("Block %d", i++); if (wu == 0) { System.out.print(" does not hold any"); } else { System.out.printf(" holds %d", wu); } System.out.println(" water units."); } } }
Write the same algorithm in Java as shown in this Go implementation.
package main import ( "fmt" "math" ) func sieve(limit uint64) []uint64 { primes := []uint64{2} c := make([]bool, limit+1) p := uint64(3) for { p2 := p * p if p2 > limit { break } for i := p2; i <= limit; i += 2 * p { c[i] = true } for { p += 2 if !c[p] { break } } } for i := uint64(3); i <= limit; i += 2 { if !c[i] { primes = append(primes, i) } } return primes } func squareFree(from, to uint64) (results []uint64) { limit := uint64(math.Sqrt(float64(to))) primes := sieve(limit) outer: for i := from; i <= to; i++ { for _, p := range primes { p2 := p * p if p2 > i { break } if i%p2 == 0 { continue outer } } results = append(results, i) } return } const trillion uint64 = 1000000000000 func main() { fmt.Println("Square-free integers from 1 to 145:") sf := squareFree(1, 145) for i := 0; i < len(sf); i++ { if i > 0 && i%20 == 0 { fmt.Println() } fmt.Printf("%4d", sf[i]) } fmt.Printf("\n\nSquare-free integers from %d to %d:\n", trillion, trillion+145) sf = squareFree(trillion, trillion+145) for i := 0; i < len(sf); i++ { if i > 0 && i%5 == 0 { fmt.Println() } fmt.Printf("%14d", sf[i]) } fmt.Println("\n\nNumber of square-free integers:\n") a := [...]uint64{100, 1000, 10000, 100000, 1000000} for _, n := range a { fmt.Printf(" from %d to %d = %d\n", 1, n, len(squareFree(1, n))) } }
import java.util.ArrayList; import java.util.List; public class SquareFree { private static List<Long> sieve(long limit) { List<Long> primes = new ArrayList<Long>(); primes.add(2L); boolean[] c = new boolean[(int)limit + 1]; long p = 3; for (;;) { long p2 = p * p; if (p2 > limit) break; for (long i = p2; i <= limit; i += 2 * p) c[(int)i] = true; for (;;) { p += 2; if (!c[(int)p]) break; } } for (long i = 3; i <= limit; i += 2) { if (!c[(int)i]) primes.add(i); } return primes; } private static List<Long> squareFree(long from, long to) { long limit = (long)Math.sqrt((double)to); List<Long> primes = sieve(limit); List<Long> results = new ArrayList<Long>(); outer: for (long i = from; i <= to; i++) { for (long p : primes) { long p2 = p * p; if (p2 > i) break; if (i % p2 == 0) continue outer; } results.add(i); } return results; } private final static long TRILLION = 1000000000000L; public static void main(String[] args) { System.out.println("Square-free integers from 1 to 145:"); List<Long> sf = squareFree(1, 145); for (int i = 0; i < sf.size(); i++) { if (i > 0 && i % 20 == 0) { System.out.println(); } System.out.printf("%4d", sf.get(i)); } System.out.print("\n\nSquare-free integers"); System.out.printf(" from %d to %d:\n", TRILLION, TRILLION + 145); sf = squareFree(TRILLION, TRILLION + 145); for (int i = 0; i < sf.size(); i++) { if (i > 0 && i % 5 == 0) System.out.println(); System.out.printf("%14d", sf.get(i)); } System.out.println("\n\nNumber of square-free integers:\n"); long[] tos = {100, 1000, 10000, 100000, 1000000}; for (long to : tos) { System.out.printf(" from %d to %d = %d\n", 1, to, squareFree(1, to).size()); } } }
Write the same code in Java as shown below in Go.
package main import ( "fmt" "math" ) func sieve(limit uint64) []uint64 { primes := []uint64{2} c := make([]bool, limit+1) p := uint64(3) for { p2 := p * p if p2 > limit { break } for i := p2; i <= limit; i += 2 * p { c[i] = true } for { p += 2 if !c[p] { break } } } for i := uint64(3); i <= limit; i += 2 { if !c[i] { primes = append(primes, i) } } return primes } func squareFree(from, to uint64) (results []uint64) { limit := uint64(math.Sqrt(float64(to))) primes := sieve(limit) outer: for i := from; i <= to; i++ { for _, p := range primes { p2 := p * p if p2 > i { break } if i%p2 == 0 { continue outer } } results = append(results, i) } return } const trillion uint64 = 1000000000000 func main() { fmt.Println("Square-free integers from 1 to 145:") sf := squareFree(1, 145) for i := 0; i < len(sf); i++ { if i > 0 && i%20 == 0 { fmt.Println() } fmt.Printf("%4d", sf[i]) } fmt.Printf("\n\nSquare-free integers from %d to %d:\n", trillion, trillion+145) sf = squareFree(trillion, trillion+145) for i := 0; i < len(sf); i++ { if i > 0 && i%5 == 0 { fmt.Println() } fmt.Printf("%14d", sf[i]) } fmt.Println("\n\nNumber of square-free integers:\n") a := [...]uint64{100, 1000, 10000, 100000, 1000000} for _, n := range a { fmt.Printf(" from %d to %d = %d\n", 1, n, len(squareFree(1, n))) } }
import java.util.ArrayList; import java.util.List; public class SquareFree { private static List<Long> sieve(long limit) { List<Long> primes = new ArrayList<Long>(); primes.add(2L); boolean[] c = new boolean[(int)limit + 1]; long p = 3; for (;;) { long p2 = p * p; if (p2 > limit) break; for (long i = p2; i <= limit; i += 2 * p) c[(int)i] = true; for (;;) { p += 2; if (!c[(int)p]) break; } } for (long i = 3; i <= limit; i += 2) { if (!c[(int)i]) primes.add(i); } return primes; } private static List<Long> squareFree(long from, long to) { long limit = (long)Math.sqrt((double)to); List<Long> primes = sieve(limit); List<Long> results = new ArrayList<Long>(); outer: for (long i = from; i <= to; i++) { for (long p : primes) { long p2 = p * p; if (p2 > i) break; if (i % p2 == 0) continue outer; } results.add(i); } return results; } private final static long TRILLION = 1000000000000L; public static void main(String[] args) { System.out.println("Square-free integers from 1 to 145:"); List<Long> sf = squareFree(1, 145); for (int i = 0; i < sf.size(); i++) { if (i > 0 && i % 20 == 0) { System.out.println(); } System.out.printf("%4d", sf.get(i)); } System.out.print("\n\nSquare-free integers"); System.out.printf(" from %d to %d:\n", TRILLION, TRILLION + 145); sf = squareFree(TRILLION, TRILLION + 145); for (int i = 0; i < sf.size(); i++) { if (i > 0 && i % 5 == 0) System.out.println(); System.out.printf("%14d", sf.get(i)); } System.out.println("\n\nNumber of square-free integers:\n"); long[] tos = {100, 1000, 10000, 100000, 1000000}; for (long to : tos) { System.out.printf(" from %d to %d = %d\n", 1, to, squareFree(1, to).size()); } } }
Ensure the translated Java code behaves exactly like the original Go snippet.
package main import "fmt" func jaro(str1, str2 string) float64 { if len(str1) == 0 && len(str2) == 0 { return 1 } if len(str1) == 0 || len(str2) == 0 { return 0 } match_distance := len(str1) if len(str2) > match_distance { match_distance = len(str2) } match_distance = match_distance/2 - 1 str1_matches := make([]bool, len(str1)) str2_matches := make([]bool, len(str2)) matches := 0. transpositions := 0. for i := range str1 { start := i - match_distance if start < 0 { start = 0 } end := i + match_distance + 1 if end > len(str2) { end = len(str2) } for k := start; k < end; k++ { if str2_matches[k] { continue } if str1[i] != str2[k] { continue } str1_matches[i] = true str2_matches[k] = true matches++ break } } if matches == 0 { return 0 } k := 0 for i := range str1 { if !str1_matches[i] { continue } for !str2_matches[k] { k++ } if str1[i] != str2[k] { transpositions++ } k++ } transpositions /= 2 return (matches/float64(len(str1)) + matches/float64(len(str2)) + (matches-transpositions)/matches) / 3 } func main() { fmt.Printf("%f\n", jaro("MARTHA", "MARHTA")) fmt.Printf("%f\n", jaro("DIXON", "DICKSONX")) fmt.Printf("%f\n", jaro("JELLYFISH", "SMELLYFISH")) }
public class JaroDistance { public static double jaro(String s, String t) { int s_len = s.length(); int t_len = t.length(); if (s_len == 0 && t_len == 0) return 1; int match_distance = Integer.max(s_len, t_len) / 2 - 1; boolean[] s_matches = new boolean[s_len]; boolean[] t_matches = new boolean[t_len]; int matches = 0; int transpositions = 0; for (int i = 0; i < s_len; i++) { int start = Integer.max(0, i-match_distance); int end = Integer.min(i+match_distance+1, t_len); for (int j = start; j < end; j++) { if (t_matches[j]) continue; if (s.charAt(i) != t.charAt(j)) continue; s_matches[i] = true; t_matches[j] = true; matches++; break; } } if (matches == 0) return 0; int k = 0; for (int i = 0; i < s_len; i++) { if (!s_matches[i]) continue; while (!t_matches[k]) k++; if (s.charAt(i) != t.charAt(k)) transpositions++; k++; } return (((double)matches / s_len) + ((double)matches / t_len) + (((double)matches - transpositions/2.0) / matches)) / 3.0; } public static void main(String[] args) { System.out.println(jaro( "MARTHA", "MARHTA")); System.out.println(jaro( "DIXON", "DICKSONX")); System.out.println(jaro("JELLYFISH", "SMELLYFISH")); } }
Convert this Go snippet to Java and keep its semantics consistent.
package main import "fmt" type pair struct{ x, y int } func main() { const max = 1685 var all []pair for a := 2; a < max; a++ { for b := a + 1; b < max-a; b++ { all = append(all, pair{a, b}) } } fmt.Println("There are", len(all), "pairs where a+b <", max, "(and a<b)") products := countProducts(all) var sPairs []pair pairs: for _, p := range all { s := p.x + p.y for a := 2; a < s/2+s&1; a++ { b := s - a if products[a*b] == 1 { continue pairs } } sPairs = append(sPairs, p) } fmt.Println("S starts with", len(sPairs), "possible pairs.") sProducts := countProducts(sPairs) var pPairs []pair for _, p := range sPairs { if sProducts[p.x*p.y] == 1 { pPairs = append(pPairs, p) } } fmt.Println("P then has", len(pPairs), "possible pairs.") pSums := countSums(pPairs) var final []pair for _, p := range pPairs { if pSums[p.x+p.y] == 1 { final = append(final, p) } } switch len(final) { case 1: fmt.Println("Answer:", final[0].x, "and", final[0].y) case 0: fmt.Println("No possible answer.") default: fmt.Println(len(final), "possible answers:", final) } } func countProducts(list []pair) map[int]int { m := make(map[int]int) for _, p := range list { m[p.x*p.y]++ } return m } func countSums(list []pair) map[int]int { m := make(map[int]int) for _, p := range list { m[p.x+p.y]++ } return m } func decomposeSum(s int) []pair { pairs := make([]pair, 0, s/2) for a := 2; a < s/2+s&1; a++ { pairs = append(pairs, pair{a, s - a}) } return pairs }
package org.rosettacode; import java.util.ArrayList; import java.util.List; public class SumAndProductPuzzle { private final long beginning; private final int maxSum; private static final int MIN_VALUE = 2; private List<int[]> firstConditionExcludes = new ArrayList<>(); private List<int[]> secondConditionExcludes = new ArrayList<>(); public static void main(String... args){ if (args.length == 0){ new SumAndProductPuzzle(100).run(); new SumAndProductPuzzle(1684).run(); new SumAndProductPuzzle(1685).run(); } else { for (String arg : args){ try{ new SumAndProductPuzzle(Integer.valueOf(arg)).run(); } catch (NumberFormatException e){ System.out.println("Please provide only integer arguments. " + "Provided argument " + arg + " was not an integer. " + "Alternatively, calling the program with no arguments " + "will run the puzzle where maximum sum equals 100, 1684, and 1865."); } } } } public SumAndProductPuzzle(int maxSum){ this.beginning = System.currentTimeMillis(); this.maxSum = maxSum; System.out.println("Run with maximum sum of " + String.valueOf(maxSum) + " started at " + String.valueOf(beginning) + "."); } public void run(){ for (int x = MIN_VALUE; x < maxSum - MIN_VALUE; x++){ for (int y = x + 1; y < maxSum - MIN_VALUE; y++){ if (isSumNoGreaterThanMax(x,y) && isSKnowsPCannotKnow(x,y) && isPKnowsNow(x,y) && isSKnowsNow(x,y) ){ System.out.println("Found solution x is " + String.valueOf(x) + " y is " + String.valueOf(y) + " in " + String.valueOf(System.currentTimeMillis() - beginning) + "ms."); } } } System.out.println("Run with maximum sum of " + String.valueOf(maxSum) + " ended in " + String.valueOf(System.currentTimeMillis() - beginning) + "ms."); } public boolean isSumNoGreaterThanMax(int x, int y){ return x + y <= maxSum; } public boolean isSKnowsPCannotKnow(int x, int y){ if (firstConditionExcludes.contains(new int[] {x, y})){ return false; } for (int[] addends : sumAddends(x, y)){ if ( !(productFactors(addends[0], addends[1]).size() > 1) ) { firstConditionExcludes.add(new int[] {x, y}); return false; } } return true; } public boolean isPKnowsNow(int x, int y){ if (secondConditionExcludes.contains(new int[] {x, y})){ return false; } int countSolutions = 0; for (int[] factors : productFactors(x, y)){ if (isSKnowsPCannotKnow(factors[0], factors[1])){ countSolutions++; } } if (countSolutions == 1){ return true; } else { secondConditionExcludes.add(new int[] {x, y}); return false; } } public boolean isSKnowsNow(int x, int y){ int countSolutions = 0; for (int[] addends : sumAddends(x, y)){ if (isPKnowsNow(addends[0], addends[1])){ countSolutions++; } } return countSolutions == 1; } public List<int[]> sumAddends(int x, int y){ List<int[]> list = new ArrayList<>(); int sum = x + y; for (int addend = MIN_VALUE; addend < sum - addend; addend++){ if (isSumNoGreaterThanMax(addend, sum - addend)){ list.add(new int[]{addend, sum - addend}); } } return list; } public List<int[]> productFactors(int x, int y){ List<int[]> list = new ArrayList<>(); int product = x * y; for (int factor = MIN_VALUE; factor < product / factor; factor++){ if (product % factor == 0){ if (isSumNoGreaterThanMax(factor, product / factor)){ list.add(new int[]{factor, product / factor}); } } } return list; } }
Produce a functionally identical Java code for the snippet given in Go.
package main import ( "fmt" "sort" "strconv" "strings" ) func fairshare(n, base int) []int { res := make([]int, n) for i := 0; i < n; i++ { j := i sum := 0 for j > 0 { sum += j % base j /= base } res[i] = sum % base } return res } func turns(n int, fss []int) string { m := make(map[int]int) for _, fs := range fss { m[fs]++ } m2 := make(map[int]int) for _, v := range m { m2[v]++ } res := []int{} sum := 0 for k, v := range m2 { sum += v res = append(res, k) } if sum != n { return fmt.Sprintf("only %d have a turn", sum) } sort.Ints(res) res2 := make([]string, len(res)) for i := range res { res2[i] = strconv.Itoa(res[i]) } return strings.Join(res2, " or ") } func main() { for _, base := range []int{2, 3, 5, 11} { fmt.Printf("%2d : %2d\n", base, fairshare(25, base)) } fmt.Println("\nHow many times does each get a turn in 50000 iterations?") for _, base := range []int{191, 1377, 49999, 50000, 50001} { t := turns(base, fairshare(50000, base)) fmt.Printf(" With %d people: %s\n", base, t) } }
import java.util.ArrayList; import java.util.Arrays; import java.util.List; public class FairshareBetweenTwoAndMore { public static void main(String[] args) { for ( int base : Arrays.asList(2, 3, 5, 11) ) { System.out.printf("Base %d = %s%n", base, thueMorseSequence(25, base)); } } private static List<Integer> thueMorseSequence(int terms, int base) { List<Integer> sequence = new ArrayList<Integer>(); for ( int i = 0 ; i < terms ; i++ ) { int sum = 0; int n = i; while ( n > 0 ) { sum += n % base; n /= base; } sequence.add(sum % base); } return sequence; } }
Produce a language-to-language conversion: from Go to Java, same semantics.
package main import ( "fmt" "sort" "strconv" "strings" ) func fairshare(n, base int) []int { res := make([]int, n) for i := 0; i < n; i++ { j := i sum := 0 for j > 0 { sum += j % base j /= base } res[i] = sum % base } return res } func turns(n int, fss []int) string { m := make(map[int]int) for _, fs := range fss { m[fs]++ } m2 := make(map[int]int) for _, v := range m { m2[v]++ } res := []int{} sum := 0 for k, v := range m2 { sum += v res = append(res, k) } if sum != n { return fmt.Sprintf("only %d have a turn", sum) } sort.Ints(res) res2 := make([]string, len(res)) for i := range res { res2[i] = strconv.Itoa(res[i]) } return strings.Join(res2, " or ") } func main() { for _, base := range []int{2, 3, 5, 11} { fmt.Printf("%2d : %2d\n", base, fairshare(25, base)) } fmt.Println("\nHow many times does each get a turn in 50000 iterations?") for _, base := range []int{191, 1377, 49999, 50000, 50001} { t := turns(base, fairshare(50000, base)) fmt.Printf(" With %d people: %s\n", base, t) } }
import java.util.ArrayList; import java.util.Arrays; import java.util.List; public class FairshareBetweenTwoAndMore { public static void main(String[] args) { for ( int base : Arrays.asList(2, 3, 5, 11) ) { System.out.printf("Base %d = %s%n", base, thueMorseSequence(25, base)); } } private static List<Integer> thueMorseSequence(int terms, int base) { List<Integer> sequence = new ArrayList<Integer>(); for ( int i = 0 ; i < terms ; i++ ) { int sum = 0; int n = i; while ( n > 0 ) { sum += n % base; n /= base; } sequence.add(sum % base); } return sequence; } }
Can you help me rewrite this code in Java instead of Go, keeping it the same logically?
package main import ( "fmt" "strings" ) var input = "3 + 4 * 2 / ( 1 - 5 ) ^ 2 ^ 3" var opa = map[string]struct { prec int rAssoc bool }{ "^": {4, true}, "*": {3, false}, "/": {3, false}, "+": {2, false}, "-": {2, false}, } func main() { fmt.Println("infix: ", input) fmt.Println("postfix:", parseInfix(input)) } func parseInfix(e string) (rpn string) { var stack []string for _, tok := range strings.Fields(e) { switch tok { case "(": stack = append(stack, tok) case ")": var op string for { op, stack = stack[len(stack)-1], stack[:len(stack)-1] if op == "(" { break } rpn += " " + op } default: if o1, isOp := opa[tok]; isOp { for len(stack) > 0 { op := stack[len(stack)-1] if o2, isOp := opa[op]; !isOp || o1.prec > o2.prec || o1.prec == o2.prec && o1.rAssoc { break } stack = stack[:len(stack)-1] rpn += " " + op } stack = append(stack, tok) } else { if rpn > "" { rpn += " " } rpn += tok } } } for len(stack) > 0 { rpn += " " + stack[len(stack)-1] stack = stack[:len(stack)-1] } return }
import java.util.Stack; public class ShuntingYard { public static void main(String[] args) { String infix = "3 + 4 * 2 / ( 1 - 5 ) ^ 2 ^ 3"; System.out.printf("infix: %s%n", infix); System.out.printf("postfix: %s%n", infixToPostfix(infix)); } static String infixToPostfix(String infix) { final String ops = "-+/*^"; StringBuilder sb = new StringBuilder(); Stack<Integer> s = new Stack<>(); for (String token : infix.split("\\s")) { if (token.isEmpty()) continue; char c = token.charAt(0); int idx = ops.indexOf(c); if (idx != -1) { if (s.isEmpty()) s.push(idx); else { while (!s.isEmpty()) { int prec2 = s.peek() / 2; int prec1 = idx / 2; if (prec2 > prec1 || (prec2 == prec1 && c != '^')) sb.append(ops.charAt(s.pop())).append(' '); else break; } s.push(idx); } } else if (c == '(') { s.push(-2); } else if (c == ')') { while (s.peek() != -2) sb.append(ops.charAt(s.pop())).append(' '); s.pop(); } else { sb.append(token).append(' '); } } while (!s.isEmpty()) sb.append(ops.charAt(s.pop())).append(' '); return sb.toString(); } }
Maintain the same structure and functionality when rewriting this code in Java.
package main import "fmt" var canFollow [][]bool var arrang []int var bFirst = true var pmap = make(map[int]bool) func init() { for _, i := range []int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37} { pmap[i] = true } } func ptrs(res, n, done int) int { ad := arrang[done-1] if n-done <= 1 { if canFollow[ad-1][n-1] { if bFirst { for _, e := range arrang { fmt.Printf("%2d ", e) } fmt.Println() bFirst = false } res++ } } else { done++ for i := done - 1; i <= n-2; i += 2 { ai := arrang[i] if canFollow[ad-1][ai-1] { arrang[i], arrang[done-1] = arrang[done-1], arrang[i] res = ptrs(res, n, done) arrang[i], arrang[done-1] = arrang[done-1], arrang[i] } } } return res } func primeTriangle(n int) int { canFollow = make([][]bool, n) for i := 0; i < n; i++ { canFollow[i] = make([]bool, n) for j := 0; j < n; j++ { _, ok := pmap[i+j+2] canFollow[i][j] = ok } } bFirst = true arrang = make([]int, n) for i := 0; i < n; i++ { arrang[i] = i + 1 } return ptrs(0, n, 1) } func main() { counts := make([]int, 19) for i := 2; i <= 20; i++ { counts[i-2] = primeTriangle(i) } fmt.Println() for i := 0; i < 19; i++ { fmt.Printf("%d ", counts[i]) } fmt.Println() }
public class PrimeTriangle { public static void main(String[] args) { long start = System.currentTimeMillis(); for (int i = 2; i <= 20; ++i) { int[] a = new int[i]; for (int j = 0; j < i; ++j) a[j] = j + 1; if (findRow(a, 0, i)) printRow(a); } System.out.println(); StringBuilder s = new StringBuilder(); for (int i = 2; i <= 20; ++i) { int[] a = new int[i]; for (int j = 0; j < i; ++j) a[j] = j + 1; if (i > 2) s.append(" "); s.append(countRows(a, 0, i)); } System.out.println(s); long finish = System.currentTimeMillis(); System.out.printf("\nElapsed time: %d milliseconds\n", finish - start); } private static void printRow(int[] a) { for (int i = 0; i < a.length; ++i) { if (i != 0) System.out.print(" "); System.out.printf("%2d", a[i]); } System.out.println(); } private static boolean findRow(int[] a, int start, int length) { if (length == 2) return isPrime(a[start] + a[start + 1]); for (int i = 1; i + 1 < length; i += 2) { if (isPrime(a[start] + a[start + i])) { swap(a, start + i, start + 1); if (findRow(a, start + 1, length - 1)) return true; swap(a, start + i, start + 1); } } return false; } private static int countRows(int[] a, int start, int length) { int count = 0; if (length == 2) { if (isPrime(a[start] + a[start + 1])) ++count; } else { for (int i = 1; i + 1 < length; i += 2) { if (isPrime(a[start] + a[start + i])) { swap(a, start + i, start + 1); count += countRows(a, start + 1, length - 1); swap(a, start + i, start + 1); } } } return count; } private static void swap(int[] a, int i, int j) { int tmp = a[i]; a[i] = a[j]; a[j] = tmp; } private static boolean isPrime(int n) { return ((1L << n) & 0x28208a20a08a28acL) != 0; } }
Write the same algorithm in Java as shown in this Go implementation.
package main import ( "fmt" "log" "math" ) func main() { fmt.Print("Enter 11 numbers: ") var s [11]float64 for i := 0; i < 11; { if n, _ := fmt.Scan(&s[i]); n > 0 { i++ } } for i, item := range s[:5] { s[i], s[10-i] = s[10-i], item } for _, item := range s { if result, overflow := f(item); overflow { log.Printf("f(%g) overflow", item) } else { fmt.Printf("f(%g) = %g\n", item, result) } } } func f(x float64) (float64, bool) { result := math.Sqrt(math.Abs(x)) + 5*x*x*x return result, result > 400 }
import java.util.*; import java.io.*; public class TPKA { public static void main(String... args) { double[] input = new double[11]; double userInput = 0.0; Scanner in = new Scanner(System.in); for(int i = 0; i < 11; i++) { System.out.print("Please enter a number: "); String s = in.nextLine(); try { userInput = Double.parseDouble(s); } catch (NumberFormatException e) { System.out.println("You entered invalid input, exiting"); System.exit(1); } input[i] = userInput; } for(int j = 10; j >= 0; j--) { double x = input[j]; double y = f(x); if( y < 400.0) { System.out.printf("f( %.2f ) = %.2f\n", x, y); } else { System.out.printf("f( %.2f ) = %s\n", x, "TOO LARGE"); } } } private static double f(double x) { return Math.pow(Math.abs(x), 0.5) + (5*(Math.pow(x, 3))); } }
Generate a Java translation of this Go snippet without changing its computational steps.
package m3 import ( "errors" "strconv" ) var ( ErrorLT3 = errors.New("N of at least three digits required.") ErrorEven = errors.New("N with odd number of digits required.") ) func Digits(i int) (string, error) { if i < 0 { i = -i } if i < 100 { return "", ErrorLT3 } s := strconv.Itoa(i) if len(s)%2 == 0 { return "", ErrorEven } m := len(s) / 2 return s[m-1 : m+2], nil }
public class MiddleThreeDigits { public static void main(String[] args) { final long[] passing = {123, 12345, 1234567, 987654321, 10001, -10001, -123, -100, 100, -12345, Long.MIN_VALUE, Long.MAX_VALUE}; final int[] failing = {1, 2, -1, -10, 2002, -2002, 0, Integer.MIN_VALUE, Integer.MAX_VALUE}; for (long n : passing) System.out.printf("middleThreeDigits(%s): %s\n", n, middleThreeDigits(n)); for (int n : failing) System.out.printf("middleThreeDigits(%s): %s\n", n, middleThreeDigits(n)); } public static <T> String middleThreeDigits(T n) { String s = String.valueOf(n); if (s.charAt(0) == '-') s = s.substring(1); int len = s.length(); if (len < 3 || len % 2 == 0) return "Need odd and >= 3 digits"; int mid = len / 2; return s.substring(mid - 1, mid + 2); } }
Rewrite this program in Java while keeping its functionality equivalent to the Go version.
package main import ( "fmt" "math" "math/big" ) var bi = new(big.Int) func isPrime(n int) bool { bi.SetUint64(uint64(n)) return bi.ProbablyPrime(0) } func generateSmallPrimes(n int) []int { primes := make([]int, n) primes[0] = 2 for i, count := 3, 1; count < n; i += 2 { if isPrime(i) { primes[count] = i count++ } } return primes } func countDivisors(n int) int { count := 1 for n%2 == 0 { n >>= 1 count++ } for d := 3; d*d <= n; d += 2 { q, r := n/d, n%d if r == 0 { dc := 0 for r == 0 { dc += count n = q q, r = n/d, n%d } count += dc } } if n != 1 { count *= 2 } return count } func main() { const max = 33 primes := generateSmallPrimes(max) z := new(big.Int) p := new(big.Int) fmt.Println("The first", max, "terms in the sequence are:") for i := 1; i <= max; i++ { if isPrime(i) { z.SetUint64(uint64(primes[i-1])) p.SetUint64(uint64(i - 1)) z.Exp(z, p, nil) fmt.Printf("%2d : %d\n", i, z) } else { count := 0 for j := 1; ; j++ { if i%2 == 1 { sq := int(math.Sqrt(float64(j))) if sq*sq != j { continue } } if countDivisors(j) == i { count++ if count == i { fmt.Printf("%2d : %d\n", i, j) break } } } } } }
import java.math.BigInteger; import java.util.ArrayList; import java.util.List; public class SequenceNthNumberWithExactlyNDivisors { public static void main(String[] args) { int max = 45; smallPrimes(max); for ( int n = 1; n <= max ; n++ ) { System.out.printf("A073916(%d) = %s%n", n, OEISA073916(n)); } } private static List<Integer> smallPrimes = new ArrayList<>(); private static void smallPrimes(int numPrimes) { smallPrimes.add(2); for ( int n = 3, count = 0 ; count < numPrimes ; n += 2 ) { if ( isPrime(n) ) { smallPrimes.add(n); count++; } } } private static final boolean isPrime(long test) { if ( test == 2 ) { return true; } if ( test % 2 == 0 ) { return false; } for ( long d = 3 ; d*d <= test ; d += 2 ) { if ( test % d == 0 ) { return false; } } return true; } private static int getDivisorCount(long n) { int count = 1; while ( n % 2 == 0 ) { n /= 2; count += 1; } for ( long d = 3 ; d*d <= n ; d += 2 ) { long q = n / d; long r = n % d; int dc = 0; while ( r == 0 ) { dc += count; n = q; q = n / d; r = n % d; } count += dc; } if ( n != 1 ) { count *= 2; } return count; } private static BigInteger OEISA073916(int n) { if ( isPrime(n) ) { return BigInteger.valueOf(smallPrimes.get(n-1)).pow(n - 1); } int count = 0; int result = 0; for ( int i = 1 ; count < n ; i++ ) { if ( n % 2 == 1 ) { int sqrt = (int) Math.sqrt(i); if ( sqrt*sqrt != i ) { continue; } } if ( getDivisorCount(i) == n ) { count++; result = i; } } return BigInteger.valueOf(result); } }
Generate an equivalent Java version of this Go code.
package main import "fmt" func countDivisors(n int) int { count := 0 for i := 1; i*i <= n; i++ { if n%i == 0 { if i == n/i { count++ } else { count += 2 } } } return count } func main() { const max = 15 seq := make([]int, max) fmt.Println("The first", max, "terms of the sequence are:") for i, n := 1, 0; n < max; i++ { if k := countDivisors(i); k <= max && seq[k-1] == 0 { seq[k-1] = i n++ } } fmt.Println(seq) }
import java.util.Arrays; public class OEIS_A005179 { static int count_divisors(int n) { int count = 0; for (int i = 1; i * i <= n; ++i) { if (n % i == 0) { if (i == n / i) count++; else count += 2; } } return count; } public static void main(String[] args) { final int max = 15; int[] seq = new int[max]; System.out.printf("The first %d terms of the sequence are:\n", max); for (int i = 1, n = 0; n < max; ++i) { int k = count_divisors(i); if (k <= max && seq[k - 1] == 0) { seq[k- 1] = i; n++; } } System.out.println(Arrays.toString(seq)); } }
Convert this Go snippet to Java and keep its semantics consistent.
package main import "fmt" func pancake(n int) int { gap, sum, adj := 2, 2, -1 for sum < n { adj++ gap = gap*2 - 1 sum += gap } return n + adj } func main() { for i := 0; i < 4; i++ { for j := 1; j < 6; j++ { n := i*5 + j fmt.Printf("p(%2d) = %2d ", n, pancake(n)) } fmt.Println() } }
public class Pancake { private static int pancake(int n) { int gap = 2; int sum = 2; int adj = -1; while (sum < n) { adj++; gap = 2 * gap - 1; sum += gap; } return n + adj; } public static void main(String[] args) { for (int i = 0; i < 4; i++) { for (int j = 1; j < 6; j++) { int n = 5 * i + j; System.out.printf("p(%2d) = %2d ", n, pancake(n)); } System.out.println(); } } }
Keep all operations the same but rewrite the snippet in Java.
package main import ( "fmt" "math/rand" "strconv" "strings" "time" ) var grid [8][8]byte func abs(i int) int { if i >= 0 { return i } else { return -i } } func createFen() string { placeKings() placePieces("PPPPPPPP", true) placePieces("pppppppp", true) placePieces("RNBQBNR", false) placePieces("rnbqbnr", false) return toFen() } func placeKings() { for { r1 := rand.Intn(8) c1 := rand.Intn(8) r2 := rand.Intn(8) c2 := rand.Intn(8) if r1 != r2 && abs(r1-r2) > 1 && abs(c1-c2) > 1 { grid[r1][c1] = 'K' grid[r2][c2] = 'k' return } } } func placePieces(pieces string, isPawn bool) { numToPlace := rand.Intn(len(pieces)) for n := 0; n < numToPlace; n++ { var r, c int for { r = rand.Intn(8) c = rand.Intn(8) if grid[r][c] == '\000' && !(isPawn && (r == 7 || r == 0)) { break } } grid[r][c] = pieces[n] } } func toFen() string { var fen strings.Builder countEmpty := 0 for r := 0; r < 8; r++ { for c := 0; c < 8; c++ { ch := grid[r][c] if ch == '\000' { ch = '.' } fmt.Printf("%2c ", ch) if ch == '.' { countEmpty++ } else { if countEmpty > 0 { fen.WriteString(strconv.Itoa(countEmpty)) countEmpty = 0 } fen.WriteByte(ch) } } if countEmpty > 0 { fen.WriteString(strconv.Itoa(countEmpty)) countEmpty = 0 } fen.WriteString("/") fmt.Println() } fen.WriteString(" w - - 0 1") return fen.String() } func main() { rand.Seed(time.Now().UnixNano()) fmt.Println(createFen()) }
import static java.lang.Math.abs; import java.util.Random; public class Fen { static Random rand = new Random(); public static void main(String[] args) { System.out.println(createFen()); } static String createFen() { char[][] grid = new char[8][8]; placeKings(grid); placePieces(grid, "PPPPPPPP", true); placePieces(grid, "pppppppp", true); placePieces(grid, "RNBQBNR", false); placePieces(grid, "rnbqbnr", false); return toFen(grid); } static void placeKings(char[][] grid) { int r1, c1, r2, c2; while (true) { r1 = rand.nextInt(8); c1 = rand.nextInt(8); r2 = rand.nextInt(8); c2 = rand.nextInt(8); if (r1 != r2 && abs(r1 - r2) > 1 && abs(c1 - c2) > 1) break; } grid[r1][c1] = 'K'; grid[r2][c2] = 'k'; } static void placePieces(char[][] grid, String pieces, boolean isPawn) { int numToPlace = rand.nextInt(pieces.length()); for (int n = 0; n < numToPlace; n++) { int r, c; do { r = rand.nextInt(8); c = rand.nextInt(8); } while (grid[r][c] != 0 || (isPawn && (r == 7 || r == 0))); grid[r][c] = pieces.charAt(n); } } static String toFen(char[][] grid) { StringBuilder fen = new StringBuilder(); int countEmpty = 0; for (int r = 0; r < 8; r++) { for (int c = 0; c < 8; c++) { char ch = grid[r][c]; System.out.printf("%2c ", ch == 0 ? '.' : ch); if (ch == 0) { countEmpty++; } else { if (countEmpty > 0) { fen.append(countEmpty); countEmpty = 0; } fen.append(ch); } } if (countEmpty > 0) { fen.append(countEmpty); countEmpty = 0; } fen.append("/"); System.out.println(); } return fen.append(" w - - 0 1").toString(); } }
Produce a functionally identical Java code for the snippet given in Go.
package main import ( "fmt" "strconv" ) func uabs(a, b uint64) uint64 { if a > b { return a - b } return b - a } func isEsthetic(n, b uint64) bool { if n == 0 { return false } i := n % b n /= b for n > 0 { j := n % b if uabs(i, j) != 1 { return false } n /= b i = j } return true } var esths []uint64 func dfs(n, m, i uint64) { if i >= n && i <= m { esths = append(esths, i) } if i == 0 || i > m { return } d := i % 10 i1 := i*10 + d - 1 i2 := i1 + 2 if d == 0 { dfs(n, m, i2) } else if d == 9 { dfs(n, m, i1) } else { dfs(n, m, i1) dfs(n, m, i2) } } func listEsths(n, n2, m, m2 uint64, perLine int, all bool) { esths = esths[:0] for i := uint64(0); i < 10; i++ { dfs(n2, m2, i) } le := len(esths) fmt.Printf("Base 10: %s esthetic numbers between %s and %s:\n", commatize(uint64(le)), commatize(n), commatize(m)) if all { for c, esth := range esths { fmt.Printf("%d ", esth) if (c+1)%perLine == 0 { fmt.Println() } } } else { for i := 0; i < perLine; i++ { fmt.Printf("%d ", esths[i]) } fmt.Println("\n............\n") for i := le - perLine; i < le; i++ { fmt.Printf("%d ", esths[i]) } } fmt.Println("\n") } 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() { for b := uint64(2); b <= 16; b++ { fmt.Printf("Base %d: %dth to %dth esthetic numbers:\n", b, 4*b, 6*b) for n, c := uint64(1), uint64(0); c < 6*b; n++ { if isEsthetic(n, b) { c++ if c >= 4*b { fmt.Printf("%s ", strconv.FormatUint(n, int(b))) } } } fmt.Println("\n") } listEsths(1000, 1010, 9999, 9898, 16, true) listEsths(1e8, 101_010_101, 13*1e7, 123_456_789, 9, true) listEsths(1e11, 101_010_101_010, 13*1e10, 123_456_789_898, 7, false) listEsths(1e14, 101_010_101_010_101, 13*1e13, 123_456_789_898_989, 5, false) listEsths(1e17, 101_010_101_010_101_010, 13*1e16, 123_456_789_898_989_898, 4, false) }
import java.util.ArrayList; import java.util.stream.IntStream; import java.util.stream.LongStream; public class EstheticNumbers { interface RecTriConsumer<A, B, C> { void accept(RecTriConsumer<A, B, C> f, A a, B b, C c); } private static boolean isEsthetic(long n, long b) { if (n == 0) { return false; } var i = n % b; var n2 = n / b; while (n2 > 0) { var j = n2 % b; if (Math.abs(i - j) != 1) { return false; } n2 /= b; i = j; } return true; } private static void listEsths(long n, long n2, long m, long m2, int perLine, boolean all) { var esths = new ArrayList<Long>(); var dfs = new RecTriConsumer<Long, Long, Long>() { public void accept(Long n, Long m, Long i) { accept(this, n, m, i); } @Override public void accept(RecTriConsumer<Long, Long, Long> f, Long n, Long m, Long i) { if (n <= i && i <= m) { esths.add(i); } if (i == 0 || i > m) { return; } var d = i % 10; var i1 = i * 10 + d - 1; var i2 = i1 + 2; if (d == 0) { f.accept(f, n, m, i2); } else if (d == 9) { f.accept(f, n, m, i1); } else { f.accept(f, n, m, i1); f.accept(f, n, m, i2); } } }; LongStream.range(0, 10).forEach(i -> dfs.accept(n2, m2, i)); var le = esths.size(); System.out.printf("Base 10: %d esthetic numbers between %d and %d:%n", le, n, m); if (all) { for (int i = 0; i < esths.size(); i++) { System.out.printf("%d ", esths.get(i)); if ((i + 1) % perLine == 0) { System.out.println(); } } } else { for (int i = 0; i < perLine; i++) { System.out.printf("%d ", esths.get(i)); } System.out.println(); System.out.println("............"); for (int i = le - perLine; i < le; i++) { System.out.printf("%d ", esths.get(i)); } } System.out.println(); System.out.println(); } public static void main(String[] args) { IntStream.rangeClosed(2, 16).forEach(b -> { System.out.printf("Base %d: %dth to %dth esthetic numbers:%n", b, 4 * b, 6 * b); var n = 1L; var c = 0L; while (c < 6 * b) { if (isEsthetic(n, b)) { c++; if (c >= 4 * b) { System.out.printf("%s ", Long.toString(n, b)); } } n++; } System.out.println(); }); System.out.println(); listEsths(1000, 1010, 9999, 9898, 16, true); listEsths((long) 1e8, 101_010_101, 13 * (long) 1e7, 123_456_789, 9, true); listEsths((long) 1e11, 101_010_101_010L, 13 * (long) 1e10, 123_456_789_898L, 7, false); listEsths((long) 1e14, 101_010_101_010_101L, 13 * (long) 1e13, 123_456_789_898_989L, 5, false); listEsths((long) 1e17, 101_010_101_010_101_010L, 13 * (long) 1e16, 123_456_789_898_989_898L, 4, false); } }
Port the provided Go code into Java while preserving the original functionality.
package main import "fmt" const ( maxn = 10 maxl = 50 ) func main() { for i := 1; i <= maxn; i++ { fmt.Printf("%d: %d\n", i, steps(i)) } } func steps(n int) int { var a, b [maxl][maxn + 1]int var x [maxl]int a[0][0] = 1 var m int for l := 0; ; { x[l]++ k := int(x[l]) if k >= n { if l <= 0 { break } l-- continue } if a[l][k] == 0 { if b[l][k+1] != 0 { continue } } else if a[l][k] != k+1 { continue } a[l+1] = a[l] for j := 1; j <= k; j++ { a[l+1][j] = a[l][k-j] } b[l+1] = b[l] a[l+1][0] = k + 1 b[l+1][k+1] = 1 if l > m-1 { m = l + 1 } l++ x[l] = 0 } return m }
public class Topswops { static final int maxBest = 32; static int[] best; static private void trySwaps(int[] deck, int f, int d, int n) { if (d > best[n]) best[n] = d; for (int i = n - 1; i >= 0; i--) { if (deck[i] == -1 || deck[i] == i) break; if (d + best[i] <= best[n]) return; } int[] deck2 = deck.clone(); for (int i = 1; i < n; i++) { final int k = 1 << i; if (deck2[i] == -1) { if ((f & k) != 0) continue; } else if (deck2[i] != i) continue; deck2[0] = i; for (int j = i - 1; j >= 0; j--) deck2[i - j] = deck[j]; trySwaps(deck2, f | k, d + 1, n); } } static int topswops(int n) { assert(n > 0 && n < maxBest); best[n] = 0; int[] deck0 = new int[n + 1]; for (int i = 1; i < n; i++) deck0[i] = -1; trySwaps(deck0, 1, 0, n); return best[n]; } public static void main(String[] args) { best = new int[maxBest]; for (int i = 1; i < 11; i++) System.out.println(i + ": " + topswops(i)); } }
Convert this Go block to Java, preserving its control flow and logic.
package main import ( "bufio" "fmt" "os" "strconv" "strings" ) func main() { units := []string{ "tochka", "liniya", "dyuim", "vershok", "piad", "fut", "arshin", "sazhen", "versta", "milia", "centimeter", "meter", "kilometer", } convs := []float32{ 0.0254, 0.254, 2.54, 4.445, 17.78, 30.48, 71.12, 213.36, 10668, 74676, 1, 100, 10000, } scanner := bufio.NewScanner(os.Stdin) for { for i, u := range units { fmt.Printf("%2d %s\n", i+1, u) } fmt.Println() var unit int var err error for { fmt.Print("Please choose a unit 1 to 13 : ") scanner.Scan() unit, err = strconv.Atoi(scanner.Text()) if err == nil && unit >= 1 && unit <= 13 { break } } unit-- var value float64 for { fmt.Print("Now enter a value in that unit : ") scanner.Scan() value, err = strconv.ParseFloat(scanner.Text(), 32) if err == nil && value >= 0 { break } } fmt.Println("\nThe equivalent in the remaining units is:\n") for i, u := range units { if i == unit { continue } fmt.Printf(" %10s : %g\n", u, float32(value)*convs[unit]/convs[i]) } fmt.Println() yn := "" for yn != "y" && yn != "n" { fmt.Print("Do another one y/n : ") scanner.Scan() yn = strings.ToLower(scanner.Text()) } if yn == "n" { return } } }
public class OldRussianMeasures { final static String[] keys = {"tochka", "liniya", "centimeter", "diuym", "vershok", "piad", "fut", "arshin", "meter", "sazhen", "kilometer", "versta", "milia"}; final static double[] values = {0.000254, 0.00254, 0.01,0.0254, 0.04445, 0.1778, 0.3048, 0.7112, 1.0, 2.1336, 1000.0, 1066.8, 7467.6}; public static void main(String[] a) { if (a.length == 2 && a[0].matches("[+-]?\\d*(\\.\\d+)?")) { double inputVal = lookup(a[1]); if (!Double.isNaN(inputVal)) { double magnitude = Double.parseDouble(a[0]); double meters = magnitude * inputVal; System.out.printf("%s %s to: %n%n", a[0], a[1]); for (String k: keys) System.out.printf("%10s: %g%n", k, meters / lookup(k)); return; } } System.out.println("Please provide a number and unit"); } public static double lookup(String key) { for (int i = 0; i < keys.length; i++) if (keys[i].equals(key)) return values[i]; return Double.NaN; } }
Generate an equivalent Java version of this Go code.
package main import ( "fmt" "math/rand" "time" ) type rateStateS struct { lastFlush time.Time period time.Duration tickCount int } func ticRate(pRate *rateStateS) { pRate.tickCount++ now := time.Now() if now.Sub(pRate.lastFlush) >= pRate.period { tps := 0. if pRate.tickCount > 0 { tps = float64(pRate.tickCount) / now.Sub(pRate.lastFlush).Seconds() } fmt.Println(tps, "tics per second.") pRate.tickCount = 0 pRate.lastFlush = now } } func somethingWeDo() { time.Sleep(time.Duration(9e7 + rand.Int63n(2e7))) } func main() { start := time.Now() rateWatch := rateStateS{ lastFlush: start, period: 5 * time.Second, } latest := start for latest.Sub(start) < 20*time.Second { somethingWeDo() ticRate(&rateWatch) latest = time.Now() } }
import java.util.function.Consumer; public class RateCounter { public static void main(String[] args) { for (double d : benchmark(10, x -> System.out.print(""), 10)) System.out.println(d); } static double[] benchmark(int n, Consumer<Integer> f, int arg) { double[] timings = new double[n]; for (int i = 0; i < n; i++) { long time = System.nanoTime(); f.accept(arg); timings[i] = System.nanoTime() - time; } return timings; } }
Change the following Go code into Java without altering its purpose.
package main import ( "fmt" "math/rand" "time" ) type rateStateS struct { lastFlush time.Time period time.Duration tickCount int } func ticRate(pRate *rateStateS) { pRate.tickCount++ now := time.Now() if now.Sub(pRate.lastFlush) >= pRate.period { tps := 0. if pRate.tickCount > 0 { tps = float64(pRate.tickCount) / now.Sub(pRate.lastFlush).Seconds() } fmt.Println(tps, "tics per second.") pRate.tickCount = 0 pRate.lastFlush = now } } func somethingWeDo() { time.Sleep(time.Duration(9e7 + rand.Int63n(2e7))) } func main() { start := time.Now() rateWatch := rateStateS{ lastFlush: start, period: 5 * time.Second, } latest := start for latest.Sub(start) < 20*time.Second { somethingWeDo() ticRate(&rateWatch) latest = time.Now() } }
import java.util.function.Consumer; public class RateCounter { public static void main(String[] args) { for (double d : benchmark(10, x -> System.out.print(""), 10)) System.out.println(d); } static double[] benchmark(int n, Consumer<Integer> f, int arg) { double[] timings = new double[n]; for (int i = 0; i < n; i++) { long time = System.nanoTime(); f.accept(arg); timings[i] = System.nanoTime() - time; } return timings; } }
Preserve the algorithm and functionality while converting the code from Go to Java.
package main import "fmt" func countDivisors(n int) int { count := 0 for i := 1; i*i <= n; i++ { if n%i == 0 { if i == n/i { count++ } else { count += 2 } } } return count } func main() { const max = 15 fmt.Println("The first", max, "terms of the sequence are:") for i, next := 1, 1; next <= max; i++ { if next == countDivisors(i) { fmt.Printf("%d ", i) next++ } } fmt.Println() }
public class AntiPrimesPlus { static int count_divisors(int n) { int count = 0; for (int i = 1; i * i <= n; ++i) { if (n % i == 0) { if (i == n / i) count++; else count += 2; } } return count; } public static void main(String[] args) { final int max = 15; System.out.printf("The first %d terms of the sequence are:\n", max); for (int i = 1, next = 1; next <= max; ++i) { if (next == count_divisors(i)) { System.out.printf("%d ", i); next++; } } System.out.println(); } }
Convert the following code from Go to Java, ensuring the logic remains intact.
package main import ( "image" "image/color" "image/draw" "image/png" "log" "os" ) const ( width, height = 800, 600 maxDepth = 11 colFactor = uint8(255 / maxDepth) fileName = "pythagorasTree.png" ) func main() { img := image.NewNRGBA(image.Rect(0, 0, width, height)) bg := image.NewUniform(color.RGBA{255, 255, 255, 255}) draw.Draw(img, img.Bounds(), bg, image.ZP, draw.Src) drawSquares(340, 550, 460, 550, img, 0) 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) } } func drawSquares(ax, ay, bx, by int, img *image.NRGBA, depth int) { if depth > maxDepth { return } dx, dy := bx-ax, ay-by x3, y3 := bx-dy, by-dx x4, y4 := ax-dy, ay-dx x5, y5 := x4+(dx-dy)/2, y4-(dx+dy)/2 col := color.RGBA{0, uint8(depth) * colFactor, 0, 255} drawLine(ax, ay, bx, by, img, col) drawLine(bx, by, x3, y3, img, col) drawLine(x3, y3, x4, y4, img, col) drawLine(x4, y4, ax, ay, img, col) drawSquares(x4, y4, x5, y5, img, depth+1) drawSquares(x5, y5, x3, y3, img, depth+1) } func drawLine(x0, y0, x1, y1 int, img *image.NRGBA, col color.RGBA) { dx := abs(x1 - x0) dy := abs(y1 - y0) var sx, sy int = -1, -1 if x0 < x1 { sx = 1 } if y0 < y1 { sy = 1 } err := dx - dy for { img.Set(x0, y0, col) if x0 == x1 && y0 == y1 { break } e2 := 2 * err if e2 > -dy { err -= dy x0 += sx } if e2 < dx { err += dx y0 += sy } } } func abs(x int) int { if x < 0 { return -x } return x }
import java.awt.*; import java.awt.geom.Path2D; import javax.swing.*; public class PythagorasTree extends JPanel { final int depthLimit = 7; float hue = 0.15f; public PythagorasTree() { setPreferredSize(new Dimension(640, 640)); setBackground(Color.white); } private void drawTree(Graphics2D g, float x1, float y1, float x2, float y2, int depth) { if (depth == depthLimit) return; float dx = x2 - x1; float dy = y1 - y2; float x3 = x2 - dy; float y3 = y2 - dx; float x4 = x1 - dy; float y4 = y1 - dx; float x5 = x4 + 0.5F * (dx - dy); float y5 = y4 - 0.5F * (dx + dy); Path2D square = new Path2D.Float(); square.moveTo(x1, y1); square.lineTo(x2, y2); square.lineTo(x3, y3); square.lineTo(x4, y4); square.closePath(); g.setColor(Color.getHSBColor(hue + depth * 0.02f, 1, 1)); g.fill(square); g.setColor(Color.lightGray); g.draw(square); Path2D triangle = new Path2D.Float(); triangle.moveTo(x3, y3); triangle.lineTo(x4, y4); triangle.lineTo(x5, y5); triangle.closePath(); g.setColor(Color.getHSBColor(hue + depth * 0.035f, 1, 1)); g.fill(triangle); g.setColor(Color.lightGray); g.draw(triangle); drawTree(g, x4, y4, x5, y5, depth + 1); drawTree(g, x5, y5, x3, y3, depth + 1); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); drawTree((Graphics2D) g, 275, 500, 375, 500, 0); } public static void main(String[] args) { SwingUtilities.invokeLater(() -> { JFrame f = new JFrame(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setTitle("Pythagoras Tree"); f.setResizable(false); f.add(new PythagorasTree(), BorderLayout.CENTER); f.pack(); f.setLocationRelativeTo(null); f.setVisible(true); }); } }
Produce a language-to-language conversion: from Go to Java, same semantics.
package main import ( "bytes" "fmt" "io" "os" "unicode" ) func main() { owp(os.Stdout, bytes.NewBufferString("what,is,the;meaning,of:life.")) fmt.Println() owp(os.Stdout, bytes.NewBufferString("we,are;not,in,kansas;any,more.")) fmt.Println() } func owp(dst io.Writer, src io.Reader) { byte_in := func () byte { bs := make([]byte, 1) src.Read(bs) return bs[0] } byte_out := func (b byte) { dst.Write([]byte{b}) } var odd func() byte odd = func() byte { s := byte_in() if unicode.IsPunct(rune(s)) { return s } b := odd() byte_out(s) return b } for { for { b := byte_in() byte_out(b) if b == '.' { return } if unicode.IsPunct(rune(b)) { break } } b := odd() byte_out(b) if b == '.' { return } } }
public class OddWord { interface CharHandler { CharHandler handle(char c) throws Exception; } final CharHandler fwd = new CharHandler() { public CharHandler handle(char c) { System.out.print(c); return (Character.isLetter(c) ? fwd : rev); } }; class Reverser extends Thread implements CharHandler { Reverser() { setDaemon(true); start(); } private Character ch; private char recur() throws Exception { notify(); while (ch == null) wait(); char c = ch, ret = c; ch = null; if (Character.isLetter(c)) { ret = recur(); System.out.print(c); } return ret; } public synchronized void run() { try { while (true) { System.out.print(recur()); notify(); } } catch (Exception e) {} } public synchronized CharHandler handle(char c) throws Exception { while (ch != null) wait(); ch = c; notify(); while (ch != null) wait(); return (Character.isLetter(c) ? rev : fwd); } } final CharHandler rev = new Reverser(); public void loop() throws Exception { CharHandler handler = fwd; int c; while ((c = System.in.read()) >= 0) { handler = handler.handle((char) c); } } public static void main(String[] args) throws Exception { new OddWord().loop(); } }
Write the same code in Java as shown below in Go.
package main import ( "fmt" "log" "math" ) var a1 = []int64{0, 1403580, -810728} var a2 = []int64{527612, 0, -1370589} const m1 = int64((1 << 32) - 209) const m2 = int64((1 << 32) - 22853) const d = m1 + 1 func mod(x, y int64) int64 { m := x % y if m < 0 { if y < 0 { return m - y } else { return m + y } } return m } type MRG32k3a struct{ x1, x2 [3]int64 } func MRG32k3aNew() *MRG32k3a { return &MRG32k3a{} } func (mrg *MRG32k3a) seed(seedState int64) { if seedState <= 0 || seedState >= d { log.Fatalf("Argument must be in the range [0, %d].\n", d) } mrg.x1 = [3]int64{seedState, 0, 0} mrg.x2 = [3]int64{seedState, 0, 0} } func (mrg *MRG32k3a) nextInt() int64 { x1i := mod(a1[0]*mrg.x1[0]+a1[1]*mrg.x1[1]+a1[2]*mrg.x1[2], m1) x2i := mod(a2[0]*mrg.x2[0]+a2[1]*mrg.x2[1]+a2[2]*mrg.x2[2], m2) mrg.x1 = [3]int64{x1i, mrg.x1[0], mrg.x1[1]} mrg.x2 = [3]int64{x2i, mrg.x2[0], mrg.x2[1]} return mod(x1i-x2i, m1) + 1 } func (mrg *MRG32k3a) nextFloat() float64 { return float64(mrg.nextInt()) / float64(d) } func main() { randomGen := MRG32k3aNew() randomGen.seed(1234567) for i := 0; i < 5; i++ { fmt.Println(randomGen.nextInt()) } var counts [5]int randomGen.seed(987654321) for i := 0; i < 1e5; i++ { j := int(math.Floor(randomGen.nextFloat() * 5)) counts[j]++ } fmt.Println("\nThe counts for 100,000 repetitions are:") for i := 0; i < 5; i++ { fmt.Printf(" %d : %d\n", i, counts[i]) } }
public class App { private static long mod(long x, long y) { long m = x % y; if (m < 0) { if (y < 0) { return m - y; } else { return m + y; } } return m; } public static class RNG { private final long[] a1 = {0, 1403580, -810728}; private static final long m1 = (1L << 32) - 209; private long[] x1; private final long[] a2 = {527612, 0, -1370589}; private static final long m2 = (1L << 32) - 22853; private long[] x2; private static final long d = m1 + 1; public void seed(long state) { x1 = new long[]{state, 0, 0}; x2 = new long[]{state, 0, 0}; } public long nextInt() { long x1i = mod(a1[0] * x1[0] + a1[1] * x1[1] + a1[2] * x1[2], m1); long x2i = mod(a2[0] * x2[0] + a2[1] * x2[1] + a2[2] * x2[2], m2); long z = mod(x1i - x2i, m1); x1 = new long[]{x1i, x1[0], x1[1]}; x2 = new long[]{x2i, x2[0], x2[1]}; return z + 1; } public double nextFloat() { return 1.0 * nextInt() / d; } } public static void main(String[] args) { RNG rng = new RNG(); rng.seed(1234567); System.out.println(rng.nextInt()); System.out.println(rng.nextInt()); System.out.println(rng.nextInt()); System.out.println(rng.nextInt()); System.out.println(rng.nextInt()); System.out.println(); int[] counts = {0, 0, 0, 0, 0}; rng.seed(987654321); for (int i = 0; i < 100_000; i++) { int value = (int) Math.floor(rng.nextFloat() * 5.0); counts[value]++; } for (int i = 0; i < counts.length; i++) { System.out.printf("%d: %d%n", i, counts[i]); } } }
Preserve the algorithm and functionality while converting the code from Go to Java.
package main import ( "fmt" "rcu" "strconv" ) func isColorful(n int) bool { if n < 0 { return false } if n < 10 { return true } digits := rcu.Digits(n, 10) for _, d := range digits { if d == 0 || d == 1 { return false } } set := make(map[int]bool) for _, d := range digits { set[d] = true } dc := len(digits) if len(set) < dc { return false } for k := 2; k <= dc; k++ { for i := 0; i <= dc-k; i++ { prod := 1 for j := i; j <= i+k-1; j++ { prod *= digits[j] } if ok := set[prod]; ok { return false } set[prod] = true } } return true } var count = make([]int, 9) var used = make([]bool, 11) var largest = 0 func countColorful(taken int, n string) { if taken == 0 { for digit := 0; digit < 10; digit++ { dx := digit + 1 used[dx] = true t := 1 if digit < 2 { t = 9 } countColorful(t, string(digit+48)) used[dx] = false } } else { nn, _ := strconv.Atoi(n) if isColorful(nn) { ln := len(n) count[ln]++ if nn > largest { largest = nn } } if taken < 9 { for digit := 2; digit < 10; digit++ { dx := digit + 1 if !used[dx] { used[dx] = true countColorful(taken+1, n+string(digit+48)) used[dx] = false } } } } } func main() { var cn []int for i := 0; i < 100; i++ { if isColorful(i) { cn = append(cn, i) } } fmt.Println("The", len(cn), "colorful numbers less than 100 are:") for i := 0; i < len(cn); i++ { fmt.Printf("%2d ", cn[i]) if (i+1)%10 == 0 { fmt.Println() } } countColorful(0, "") fmt.Println("\n\nThe largest possible colorful number is:") fmt.Println(rcu.Commatize(largest)) fmt.Println("\nCount of colorful numbers for each order of magnitude:") pow := 10 for dc := 1; dc < len(count); dc++ { cdc := rcu.Commatize(count[dc]) pc := 100 * float64(count[dc]) / float64(pow) fmt.Printf(" %d digit colorful number count: %6s - %7.3f%%\n", dc, cdc, pc) if pow == 10 { pow = 90 } else { pow *= 10 } } sum := 0 for _, c := range count { sum += c } fmt.Printf("\nTotal colorful numbers: %s\n", rcu.Commatize(sum)) }
public class ColorfulNumbers { private int count[] = new int[8]; private boolean used[] = new boolean[10]; private int largest = 0; public static void main(String[] args) { System.out.printf("Colorful numbers less than 100:\n"); for (int n = 0, count = 0; n < 100; ++n) { if (isColorful(n)) System.out.printf("%2d%c", n, ++count % 10 == 0 ? '\n' : ' '); } ColorfulNumbers c = new ColorfulNumbers(); System.out.printf("\n\nLargest colorful number: %,d\n", c.largest); System.out.printf("\nCount of colorful numbers by number of digits:\n"); int total = 0; for (int d = 0; d < 8; ++d) { System.out.printf("%d  %,d\n", d + 1, c.count[d]); total += c.count[d]; } System.out.printf("\nTotal: %,d\n", total); } private ColorfulNumbers() { countColorful(0, 0, 0); } public static boolean isColorful(int n) { if (n < 0 || n > 98765432) return false; int digit_count[] = new int[10]; int digits[] = new int[8]; int num_digits = 0; for (int m = n; m > 0; m /= 10) { int d = m % 10; if (n > 9 && (d == 0 || d == 1)) return false; if (++digit_count[d] > 1) return false; digits[num_digits++] = d; } int products[] = new int[36]; for (int i = 0, product_count = 0; i < num_digits; ++i) { for (int j = i, p = 1; j < num_digits; ++j) { p *= digits[j]; for (int k = 0; k < product_count; ++k) { if (products[k] == p) return false; } products[product_count++] = p; } } return true; } private void countColorful(int taken, int n, int digits) { if (taken == 0) { for (int d = 0; d < 10; ++d) { used[d] = true; countColorful(d < 2 ? 9 : 1, d, 1); used[d] = false; } } else { if (isColorful(n)) { ++count[digits - 1]; if (n > largest) largest = n; } if (taken < 9) { for (int d = 2; d < 10; ++d) { if (!used[d]) { used[d] = true; countColorful(taken + 1, n * 10 + d, digits + 1); used[d] = false; } } } } } }
Produce a functionally identical Java code for the snippet given in Go.
package main import ( "fmt" "rcu" "strconv" ) func isColorful(n int) bool { if n < 0 { return false } if n < 10 { return true } digits := rcu.Digits(n, 10) for _, d := range digits { if d == 0 || d == 1 { return false } } set := make(map[int]bool) for _, d := range digits { set[d] = true } dc := len(digits) if len(set) < dc { return false } for k := 2; k <= dc; k++ { for i := 0; i <= dc-k; i++ { prod := 1 for j := i; j <= i+k-1; j++ { prod *= digits[j] } if ok := set[prod]; ok { return false } set[prod] = true } } return true } var count = make([]int, 9) var used = make([]bool, 11) var largest = 0 func countColorful(taken int, n string) { if taken == 0 { for digit := 0; digit < 10; digit++ { dx := digit + 1 used[dx] = true t := 1 if digit < 2 { t = 9 } countColorful(t, string(digit+48)) used[dx] = false } } else { nn, _ := strconv.Atoi(n) if isColorful(nn) { ln := len(n) count[ln]++ if nn > largest { largest = nn } } if taken < 9 { for digit := 2; digit < 10; digit++ { dx := digit + 1 if !used[dx] { used[dx] = true countColorful(taken+1, n+string(digit+48)) used[dx] = false } } } } } func main() { var cn []int for i := 0; i < 100; i++ { if isColorful(i) { cn = append(cn, i) } } fmt.Println("The", len(cn), "colorful numbers less than 100 are:") for i := 0; i < len(cn); i++ { fmt.Printf("%2d ", cn[i]) if (i+1)%10 == 0 { fmt.Println() } } countColorful(0, "") fmt.Println("\n\nThe largest possible colorful number is:") fmt.Println(rcu.Commatize(largest)) fmt.Println("\nCount of colorful numbers for each order of magnitude:") pow := 10 for dc := 1; dc < len(count); dc++ { cdc := rcu.Commatize(count[dc]) pc := 100 * float64(count[dc]) / float64(pow) fmt.Printf(" %d digit colorful number count: %6s - %7.3f%%\n", dc, cdc, pc) if pow == 10 { pow = 90 } else { pow *= 10 } } sum := 0 for _, c := range count { sum += c } fmt.Printf("\nTotal colorful numbers: %s\n", rcu.Commatize(sum)) }
public class ColorfulNumbers { private int count[] = new int[8]; private boolean used[] = new boolean[10]; private int largest = 0; public static void main(String[] args) { System.out.printf("Colorful numbers less than 100:\n"); for (int n = 0, count = 0; n < 100; ++n) { if (isColorful(n)) System.out.printf("%2d%c", n, ++count % 10 == 0 ? '\n' : ' '); } ColorfulNumbers c = new ColorfulNumbers(); System.out.printf("\n\nLargest colorful number: %,d\n", c.largest); System.out.printf("\nCount of colorful numbers by number of digits:\n"); int total = 0; for (int d = 0; d < 8; ++d) { System.out.printf("%d  %,d\n", d + 1, c.count[d]); total += c.count[d]; } System.out.printf("\nTotal: %,d\n", total); } private ColorfulNumbers() { countColorful(0, 0, 0); } public static boolean isColorful(int n) { if (n < 0 || n > 98765432) return false; int digit_count[] = new int[10]; int digits[] = new int[8]; int num_digits = 0; for (int m = n; m > 0; m /= 10) { int d = m % 10; if (n > 9 && (d == 0 || d == 1)) return false; if (++digit_count[d] > 1) return false; digits[num_digits++] = d; } int products[] = new int[36]; for (int i = 0, product_count = 0; i < num_digits; ++i) { for (int j = i, p = 1; j < num_digits; ++j) { p *= digits[j]; for (int k = 0; k < product_count; ++k) { if (products[k] == p) return false; } products[product_count++] = p; } } return true; } private void countColorful(int taken, int n, int digits) { if (taken == 0) { for (int d = 0; d < 10; ++d) { used[d] = true; countColorful(d < 2 ? 9 : 1, d, 1); used[d] = false; } } else { if (isColorful(n)) { ++count[digits - 1]; if (n > largest) largest = n; } if (taken < 9) { for (int d = 2; d < 10; ++d) { if (!used[d]) { used[d] = true; countColorful(taken + 1, n * 10 + d, digits + 1); used[d] = false; } } } } } }
Generate an equivalent Java version of this Go code.
package main import ( "fmt" "rcu" "strconv" ) func isColorful(n int) bool { if n < 0 { return false } if n < 10 { return true } digits := rcu.Digits(n, 10) for _, d := range digits { if d == 0 || d == 1 { return false } } set := make(map[int]bool) for _, d := range digits { set[d] = true } dc := len(digits) if len(set) < dc { return false } for k := 2; k <= dc; k++ { for i := 0; i <= dc-k; i++ { prod := 1 for j := i; j <= i+k-1; j++ { prod *= digits[j] } if ok := set[prod]; ok { return false } set[prod] = true } } return true } var count = make([]int, 9) var used = make([]bool, 11) var largest = 0 func countColorful(taken int, n string) { if taken == 0 { for digit := 0; digit < 10; digit++ { dx := digit + 1 used[dx] = true t := 1 if digit < 2 { t = 9 } countColorful(t, string(digit+48)) used[dx] = false } } else { nn, _ := strconv.Atoi(n) if isColorful(nn) { ln := len(n) count[ln]++ if nn > largest { largest = nn } } if taken < 9 { for digit := 2; digit < 10; digit++ { dx := digit + 1 if !used[dx] { used[dx] = true countColorful(taken+1, n+string(digit+48)) used[dx] = false } } } } } func main() { var cn []int for i := 0; i < 100; i++ { if isColorful(i) { cn = append(cn, i) } } fmt.Println("The", len(cn), "colorful numbers less than 100 are:") for i := 0; i < len(cn); i++ { fmt.Printf("%2d ", cn[i]) if (i+1)%10 == 0 { fmt.Println() } } countColorful(0, "") fmt.Println("\n\nThe largest possible colorful number is:") fmt.Println(rcu.Commatize(largest)) fmt.Println("\nCount of colorful numbers for each order of magnitude:") pow := 10 for dc := 1; dc < len(count); dc++ { cdc := rcu.Commatize(count[dc]) pc := 100 * float64(count[dc]) / float64(pow) fmt.Printf(" %d digit colorful number count: %6s - %7.3f%%\n", dc, cdc, pc) if pow == 10 { pow = 90 } else { pow *= 10 } } sum := 0 for _, c := range count { sum += c } fmt.Printf("\nTotal colorful numbers: %s\n", rcu.Commatize(sum)) }
public class ColorfulNumbers { private int count[] = new int[8]; private boolean used[] = new boolean[10]; private int largest = 0; public static void main(String[] args) { System.out.printf("Colorful numbers less than 100:\n"); for (int n = 0, count = 0; n < 100; ++n) { if (isColorful(n)) System.out.printf("%2d%c", n, ++count % 10 == 0 ? '\n' : ' '); } ColorfulNumbers c = new ColorfulNumbers(); System.out.printf("\n\nLargest colorful number: %,d\n", c.largest); System.out.printf("\nCount of colorful numbers by number of digits:\n"); int total = 0; for (int d = 0; d < 8; ++d) { System.out.printf("%d  %,d\n", d + 1, c.count[d]); total += c.count[d]; } System.out.printf("\nTotal: %,d\n", total); } private ColorfulNumbers() { countColorful(0, 0, 0); } public static boolean isColorful(int n) { if (n < 0 || n > 98765432) return false; int digit_count[] = new int[10]; int digits[] = new int[8]; int num_digits = 0; for (int m = n; m > 0; m /= 10) { int d = m % 10; if (n > 9 && (d == 0 || d == 1)) return false; if (++digit_count[d] > 1) return false; digits[num_digits++] = d; } int products[] = new int[36]; for (int i = 0, product_count = 0; i < num_digits; ++i) { for (int j = i, p = 1; j < num_digits; ++j) { p *= digits[j]; for (int k = 0; k < product_count; ++k) { if (products[k] == p) return false; } products[product_count++] = p; } } return true; } private void countColorful(int taken, int n, int digits) { if (taken == 0) { for (int d = 0; d < 10; ++d) { used[d] = true; countColorful(d < 2 ? 9 : 1, d, 1); used[d] = false; } } else { if (isColorful(n)) { ++count[digits - 1]; if (n > largest) largest = n; } if (taken < 9) { for (int d = 2; d < 10; ++d) { if (!used[d]) { used[d] = true; countColorful(taken + 1, n * 10 + d, digits + 1); used[d] = false; } } } } } }
Change the programming language of this snippet from Go to Java without modifying what it does.
package main import ( "fmt" "html" "io/ioutil" "net/http" "regexp" "strings" "time" ) func main() { ex := `<li><a href="/wiki/(.*?)"` re := regexp.MustCompile(ex) page := "http: resp, _ := http.Get(page) body, _ := ioutil.ReadAll(resp.Body) matches := re.FindAllStringSubmatch(string(body), -1) resp.Body.Close() tasks := make([]string, len(matches)) for i, match := range matches { tasks[i] = match[1] } const base = "http: const limit = 3 ex = `(?s)using any language you may know.</div>(.*?)<div id="toc"` ex2 := `</?[^>]*>` re = regexp.MustCompile(ex) re2 := regexp.MustCompile(ex2) for i, task := range tasks { page = base + task resp, _ = http.Get(page) body, _ = ioutil.ReadAll(resp.Body) match := re.FindStringSubmatch(string(body)) resp.Body.Close() text := html.UnescapeString(re2.ReplaceAllLiteralString(match[1], "")) fmt.Println(strings.Replace(task, "_", " ", -1), "\n", text) if i == limit-1 { break } time.Sleep(5 * time.Second) } }
import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import java.net.http.HttpClient; import java.net.http.HttpRequest; import java.net.http.HttpResponse; import java.time.Duration; import java.util.ArrayList; import java.util.regex.Pattern; public class TasksWithoutExamples { private static String readPage(HttpClient client, URI uri) throws IOException, InterruptedException { var request = HttpRequest.newBuilder() .GET() .uri(uri) .timeout(Duration.ofSeconds(5)) .setHeader("accept", "text/html") .build(); var response = client.send(request, HttpResponse.BodyHandlers.ofString()); return response.body(); } private static void process(HttpClient client, String base, String task) { try { var re = Pattern.compile(".*using any language you may know.</div>(.*?)<div id=\"toc\".*", Pattern.DOTALL + Pattern.MULTILINE); var re2 = Pattern.compile("</?[^>]*>"); var page = base + task; String body = readPage(client, new URI(page)); var matcher = re.matcher(body); if (matcher.matches()) { var group = matcher.group(1); var m2 = re2.matcher(group); var text = m2.replaceAll(""); System.out.println(text); } } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) throws URISyntaxException, IOException, InterruptedException { var re = Pattern.compile("<li><a href=\"/wiki/(.*?)\"", Pattern.DOTALL + Pattern.MULTILINE); var client = HttpClient.newBuilder() .version(HttpClient.Version.HTTP_1_1) .followRedirects(HttpClient.Redirect.NORMAL) .connectTimeout(Duration.ofSeconds(5)) .build(); var uri = new URI("http", "rosettacode.org", "/wiki/Category:Programming_Tasks", ""); var body = readPage(client, uri); var matcher = re.matcher(body); var tasks = new ArrayList<String>(); while (matcher.find()) { tasks.add(matcher.group(1)); } var base = "http: var limit = 3L; tasks.stream().limit(limit).forEach(task -> process(client, base, task)); } }
Rewrite the snippet below in Java so it works the same as the original Go code.
package main import ( "fmt" "os/exec" ) func main() { synthType := "sine" duration := "5" frequency := "440" cmd := exec.Command("play", "-n", "synth", duration, synthType, frequency) err := cmd.Run() if err != nil { fmt.Println(err) } }
import processing.sound.*; SinOsc sine; size(500,500); sine = new SinOsc(this); sine.freq(500); sine.play(); delay(5000);
Generate a Java translation of this Go snippet without changing its computational steps.
package main import "fmt" func hello() { fmt.Println("Hello from main.go") } func main() { hello() hello2() }
public class Class1 extends Class2 { }
Rewrite the snippet below in Java so it works the same as the original Go code.
package main import "fmt" func hello() { fmt.Println("Hello from main.go") } func main() { hello() hello2() }
public class Class1 extends Class2 { }
Change the programming language of this snippet from Go to Java without modifying what it does.
package main import ( "fmt" "sternbrocot" ) func main() { g := sb.Generator() fmt.Println("First 15:") for i := 1; i <= 15; i++ { fmt.Printf("%2d: %d\n", i, g()) } s := sb.New() fmt.Println("First 15:", s.FirstN(15)) for _, x := range []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 100} { fmt.Printf("%3d at 1-based index %d\n", x, 1+s.Find(x)) } fmt.Println("1-based indexes: gcd") for n, f := range s.FirstN(1000)[:999] { g := gcd(f, (*s)[n+1]) fmt.Printf("%d,%d: gcd(%d, %d) = %d\n", n+1, n+2, f, (*s)[n+1], g) if g != 1 { panic("oh no!") return } } } func gcd(x, y int) int { for y != 0 { x, y = y, x%y } return x }
import java.math.BigInteger; import java.util.LinkedList; public class SternBrocot { static LinkedList<Integer> sequence = new LinkedList<Integer>(){{ add(1); add(1); }}; private static void genSeq(int n){ for(int conIdx = 1; sequence.size() < n; conIdx++){ int consider = sequence.get(conIdx); int pre = sequence.get(conIdx - 1); sequence.add(consider + pre); sequence.add(consider); } } public static void main(String[] args){ genSeq(1200); System.out.println("The first 15 elements are: " + sequence.subList(0, 15)); for(int i = 1; i <= 10; i++){ System.out.println("First occurrence of " + i + " is at " + (sequence.indexOf(i) + 1)); } System.out.println("First occurrence of 100 is at " + (sequence.indexOf(100) + 1)); boolean failure = false; for(int i = 0; i < 999; i++){ failure |= !BigInteger.valueOf(sequence.get(i)).gcd(BigInteger.valueOf(sequence.get(i + 1))).equals(BigInteger.ONE); } System.out.println("All GCDs are" + (failure ? " not" : "") + " 1"); } }
Produce a language-to-language conversion: from Go to Java, same semantics.
package main import ( "fmt" "math" ) type unc struct { n float64 s float64 } func newUnc(n, s float64) *unc { return &unc{n, s * s} } func (z *unc) errorTerm() float64 { return math.Sqrt(z.s) } func (z *unc) addC(a *unc, c float64) *unc { *z = *a z.n += c return z } func (z *unc) subC(a *unc, c float64) *unc { *z = *a z.n -= c return z } func (z *unc) addU(a, b *unc) *unc { z.n = a.n + b.n z.s = a.s + b.s return z } func (z *unc) subU(a, b *unc) *unc { z.n = a.n - b.n z.s = a.s + b.s return z } func (z *unc) mulC(a *unc, c float64) *unc { z.n = a.n * c z.s = a.s * c * c return z } func (z *unc) divC(a *unc, c float64) *unc { z.n = a.n / c z.s = a.s / (c * c) return z } func (z *unc) mulU(a, b *unc) *unc { prod := a.n * b.n z.n, z.s = prod, prod*prod*(a.s/(a.n*a.n)+b.s/(b.n*b.n)) return z } func (z *unc) divU(a, b *unc) *unc { quot := a.n / b.n z.n, z.s = quot, quot*quot*(a.s/(a.n*a.n)+b.s/(b.n*b.n)) return z } func (z *unc) expC(a *unc, c float64) *unc { f := math.Pow(a.n, c) g := f * c / a.n z.n = f z.s = a.s * g * g return z } func main() { x1 := newUnc(100, 1.1) x2 := newUnc(200, 2.2) y1 := newUnc(50, 1.2) y2 := newUnc(100, 2.3) var d, d2 unc d.expC(d.addU(d.expC(d.subU(x1, x2), 2), d2.expC(d2.subU(y1, y2), 2)), .5) fmt.Println("d: ", d.n) fmt.Println("error:", d.errorTerm()) }
public class Approx { private double value; private double error; public Approx(){this.value = this.error = 0;} public Approx(Approx b){ this.value = b.value; this.error = b.error; } public Approx(double value, double error){ this.value = value; this.error = error; } public Approx add(Approx b){ value+= b.value; error = Math.sqrt(error * error + b.error * b.error); return this; } public Approx add(double b){ value+= b; return this; } public Approx sub(Approx b){ value-= b.value; error = Math.sqrt(error * error + b.error * b.error); return this; } public Approx sub(double b){ value-= b; return this; } public Approx mult(Approx b){ double oldVal = value; value*= b.value; error = Math.sqrt(value * value * (error*error) / (oldVal*oldVal) + (b.error*b.error) / (b.value*b.value)); return this; } public Approx mult(double b){ value*= b; error = Math.abs(b * error); return this; } public Approx div(Approx b){ double oldVal = value; value/= b.value; error = Math.sqrt(value * value * (error*error) / (oldVal*oldVal) + (b.error*b.error) / (b.value*b.value)); return this; } public Approx div(double b){ value/= b; error = Math.abs(b * error); return this; } public Approx pow(double b){ double oldVal = value; value = Math.pow(value, b); error = Math.abs(value * b * (error / oldVal)); return this; } @Override public String toString(){return value+"±"+error;} public static void main(String[] args){ Approx x1 = new Approx(100, 1.1); Approx y1 = new Approx(50, 1.2); Approx x2 = new Approx(200, 2.2); Approx y2 = new Approx(100, 2.3); x1.sub(x2).pow(2).add(y1.sub(y2).pow(2)).pow(0.5); System.out.println(x1); } }