Java

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));    }}