Java Utililty Methods Array Permute

List of utility methods to do Array Permute

  1. HOME
  2. Java
  3. A
  4. Array Permute

Description

The list of methods to do Array Permute are organized into topic(s).

Method

int[]permutation(final int start, final int end)
Creates a permutation of all integers in the interval [start, end] 
if (start > end)
    return new int[0];
final int length = end - start + 1;
final int[] r = new int[length];
for (int i = 0; i < length; i++)
    r[i] = start + i;
for (int i = length - 1; i > 0; i--) {
    final int j = random.nextInt(i + 1);
...
int[]permutation(int n)
Generates a random permutation of the numbers {0, ..., n-1} 
return permutation(n, getRandomGenerator());
Object[]permute(int k, Object[] os)
permute 
for (int j = 2; j <= os.length; j++) {
    k = k / (j - 1);
    Object tmp = os[j - 1];
    os[j - 1] = os[(k % j)];
    os[(k % j)] = tmp;
return os;
voidpermute(int[] elements, int i, int j)
permute 
int temp;
temp = elements[i];
elements[i] = elements[j];
elements[j] = temp;
int[]permute(int[] in, int[] idx)
permute 
int[] out = new int[in.length];
for (int i = 0; i < in.length; i++)
    out[i] = in[idx[i]];
return out;
Object[]permute(int[] p, Object[] data, boolean clone)
Rearrange the specified data according to the specified permutation. 
Object[] permuted = null;
if (clone) {
    permuted = (Object[]) data.clone();
    for (int i = 0; i < data.length; i++)
        permuted[p[i]] = data[i];
} else {
    int i = 0;
    while (i < p.length) {
...
voidpermute(String str, int startIndex, int endIndex)
Algo {A,B,C} first take index 0 and swap with all A swap with A {A,B,C} ---> now take second char and make first char fixed {A,B,C} and {A,C,B} A swap with B {B,A,C} ---> now take second char and make first char fixed {B,A,C} and {B,C,A} A swap with C {C,B,A} ---> now take second char and make first char fixed {C,B,A} and {C,A,B} now take second char on each 
if (startIndex == endIndex) {
    System.out.println(str);
} else {
    for (int i = startIndex; i <= endIndex; i++) {
        str = swap(str, startIndex, i);
        permute(str, startIndex + 1, endIndex);
        str = swap(str, startIndex, i);
voidpermute(T[] array)
Randomly permute the values in array . 
Collections.shuffle(Arrays.asList(array));
T[]permute(T[] values)
"Randomly" permute an array in place. 
for (int i = 0; i < values.length; i++) {
    swap(values, i, generator.nextInt(values.length));
return values;
int[]permuteArray(int[] array, Integer[] permutation)
permute Array 
int[] output = new int[array.length];
for (int i = 0; i < output.length; i++) {
    output[i] = array[permutation[i]];
return output;