Java : Program to print all permutations of a given string.

A permutation, also called an “arrangement number” or “order,” is a rearrangement of the elements of an ordered list S into a one-to-one correspondence with S itself. A string of length n has n! permutation.

Below are the permutations of string ABC. ABC, ACB, BAC, BCA, CAB, CBA

public class Ques2 {

    /**

     * @param args the command line arguments

     */

   public static void permutation(String str) { 

    permutation("", str); 

}

private static void permutation(String prefix, String str) {

    int n = str.length();

    if (n == 0) System.out.println(prefix);

    else {

        for (int i = 0; i < n; i++)

            permutation(prefix + str.charAt(i), str.substring(0, i) + str.substring(i+1, n));

    }

}

        

    public static void main(String[] args) throws IOException {

       String str="abc";

       permutation(str);

}

}