Solving Jumble:

# Find a common word that is a jumble of the letters RGYUEN

Solution:

import java.util.*;

import java.lang.*;

import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */

class Ideone

{

 public static void main (String[] args) throws java.lang.Exception

 {

  String a = "RGYUEN";

  StringBuilder b = new StringBuilder();

  List<String> permutations = new ArrayList<String>();

  boolean[] used = new boolean[a.length()];

  permute(a, b, used, 0, a.length()-1, perumations);

  for (int i = 0; i < permutations.size(); i++) {

   if (isValid(permutations.get(i))) {

    System.out.println(permutations.get(i));

   }

  }

 }

 public static void permute(String a, StringBuilder b, boolean[] used, int start, int end, List<String> permutations) {

  if (b.length() == end - start + 1) {

   permutations.add(b.toString());

   return;

  }

  for (int i = start; i <= end; i++) {

   if (used[i]) continue;

   used[i] = true;

                                            b.append(a.charAt(i));

   permute(a, b, used, start, end, permutations);

   b.deleteCharAt(b.length()-1);

   used[i] = false;

  }

 }

 public static boolean isValid(String s) {

  if ((s.charAt(0) == 'G' || s.charAt(2) == 'Y' || s.charAt(5) == 'R') &&

      (s.charAt(0) == 'G' || s.charAt(2) == 'Y' || s.charAt(5) == 'R') &&

      (s.charAt(0) == 'G' || s.charAt(2) == 'Y' || s.charAt(5) == 'R'))

      return true;

  return false;

 }

}

Answer: Gurney