Java solution

 public static String biggerIsGreater(String w) {
// Write your code here

  String[] strSplit = w.split("");

  for(int i = w.length() -1 ; i >= 0; i--){
      for(int j = w.length() -1 ; j > i; j--){
          if(strSplit[i].charAt(0) < strSplit[j].charAt(0)){

              StringBuilder stringBuilder = new StringBuilder(w.substring(j+1));
              StringBuilder stringBuilder2 = new StringBuilder(w.substring(i + 1,j));

              return w.substring(0, i) + 
              w.charAt(j) + 
              stringBuilder.reverse().toString() + 
              w.charAt(i) +
              stringBuilder2.reverse().toString();
          }
      }
  }

  return "no answer";

}