public class Permuter{
private static void permute(int n, char[] a){
if (n == 0){
System.out.println(String.valueOf(a));}
else{
for (int i=0; i<= n; i++){
permute(n-1, a);
swap(a, n % 2 == 0 ? i : 0, n);}}}
private static void swap(char[] a, int i, int j){
char saved = a[i];