Efficient String Permutation Program.

The following piece of a code is a very efficient use of recursion to find the possible permutation of a string.

public class Permutations {

   public  static void perm1(String s) { perm1("", s); }

   private static void perm1(String prefix, String s) {
        int N = s.length();
        if (N == 0)
            System.out.println(prefix);
        else {
            for(int i = 0; i < N; i++){
               perm1(prefix + s.charAt(i), s.substring(0, i) + s.substring(i+1, N));
            }
        }
    }
    public static void main(String[] args) {
       String alphabet = "Test";
       String elements = alphabet.substring(0, alphabet.length());
       perm1(elements);
    }
}

Debugging this code might prove to be a little difficult though but excellent logic though.

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