stringPermRecursion

package stringpermrecursion;

import javax.swing.*;

public class StringPermRecursion {

    public static void main(String[] args) {
        //ask for a string
        String input = JOptionPane.showInputDialog("Input a string:");

        //transfer the input to a string array
        char arrayStr[] = input.toCharArray();

        //pass the string, pointers to first and last element of string
        permutation( arrayStr , 0, input.length() - 1 );
    }

    public static void permutation( char[] arr, int strLeft, int strRight ){
        if( strLeft == strRight ){
            for(int i = 0; i < arr.length; i++){
                System.out.print( arr[ i ]);
            }

            System.out.print( "\n" );
        }
        else{
            for(int i = strLeft; i <= strRight; i++ ){
                swap( arr, strLeft, i );
                permutation( arr, strLeft+1, strRight );
                swap( arr, strLeft, i );
            }
        }
    }

    //swap two elements of the array
    public static void swap( char[] a, int l, int j ){
        char temp = a[l];
        a[l] = a[j];
        a[j] = temp;
    }
}