This is most likely a performance issue with the code.
Some tests will take pretty long strings.
Instead of string concat ( += ) try using StringBuilder.

Same problem here...

Hi, I have the same Problem, this is my code:

private static String reverse(String s){
  String reversed = "";
  for (int i = s.length() - 1; i >= 0; i--)
    reversed += s.charAt(i);
  return reversed;
}
public static String shorterReverseLonger(String a, String b) {
  return (a.length() < b.length()) ? a + reverse(b) + a :  b + reverse(a) + b;
}

You should share your code. Otherwise one would have to use magic crystal balls to find out why your code is running to slow.

I am facing the same problem, can sombody help us!!