87. Scramble String

public class Solution { public boolean isScramble(String s1, String s2) { if (s1.length() != s2.length()) return false; if (s1.equals(s2)) return true; char[] c1 = s1.toCharArray(); char[] c2 = s2.toCharArray(); Arrays.sort(c1); Arrays.sort(c2); if (!Arrays.equals(c1, c2)) return false; for (int i = 1; i < s1.length(); i++) { if (isScramble(s1.substring(0, i), s2.substring(0, i)) && isScramble(s1.substring(i), s2.substring(i))) return true; if (isScramble(s1.substring(0, i), s2.substring(s2.length() - i)) && isScramble(s1.substring(i), s2.substring(0, s2.length() - i))) return true; } return false; } }