Permutaciones: Sin repetición / Importa orden. (forma no recursiva)

Código:

//* Permutaciones (Forma no recursiva)
//- Importa posición
//- Sin repetición
package permutar3;

import java.util.Arrays;

public class Permutar3 {

    public static void main(String[] args) {
        int[] perm = {0, 1, 2, 3, 4, 5};
        do {
            System.out.println(Arrays.toString(perm));
        } while (nextPermutation(perm));
    }

    private static boolean nextPermutation(int[] array) {

        int i = array.length - 1;
        while (i > 0 && array[i - 1] >= array[i]) {
            i--;
        }

        if (i <= 0) {
            return false;
        }

        int j = array.length - 1;
        while (array[j] <= array[i - 1]) {
            j--;
        }

        int temp = array[i - 1];
        array[i - 1] = array[j];
        array[j] = temp;

        j = array.length - 1;
        while (i < j) {
            temp = array[i];
            array[i] = array[j];
            array[j] = temp;
            i++;
            j--;
        }
        return true;
    }
}

Resultado:

run:

[0, 1, 2, 3, 4, 5]

[0, 1, 2, 3, 5, 4]

[0, 1, 2, 4, 3, 5]

[0, 1, 2, 4, 5, 3]

[0, 1, 2, 5, 3, 4]

[0, 1, 2, 5, 4, 3]

[0, 1, 3, 2, 4, 5]

[0, 1, 3, 2, 5, 4]

...

...

...

[5, 4, 2, 3, 0, 1]

[5, 4, 2, 3, 1, 0]

[5, 4, 3, 0, 1, 2]

[5, 4, 3, 0, 2, 1]

[5, 4, 3, 1, 0, 2]

[5, 4, 3, 1, 2, 0]

[5, 4, 3, 2, 0, 1]

[5, 4, 3, 2, 1, 0]

BUILD SUCCESSFUL (total time: 0 seconds)