/*

bool isSame(string s1, string s2) {

int hash[26];

for (int i = 0; i < 26; i++) {

hash[i] = 0;

}

for (unsigned i = 0; i < s1.length(); i++) {

hash[s1[i] - 'a']++;

}

for (unsigned i = 0; i < s1.length(); i++) {

hash[s2[i] - 'a']--;

if (hash[s2[i] - 'a'] < 0) {

return false;

}

}

return true;

}

bool isScramble(string s1, string s2) {

unsigned len = s1.length();

if (len != s2.length()) {

return false;

}

if (len <= 2) {

return isSame(s1, s2);

}

for (unsigned i = 1; i < len; i++) {

if (isSame(s1.substr(0, i), s2.substr(0, i))

&& isSame(s1.substr(i, len - i), s2.substr(i, len - i))) {

bool left = isScramble(s1.substr(0, i), s2.substr(0, i));

bool right = isScramble(s1.substr(i, len - i),

s2.substr(i, len - i));

if (left && right) {

return true;

}

} else if (isSame(s1.substr(0, i), s2.substr(len - i, i))

&& isSame(s1.substr(i, len - i), s2.substr(0, len - i))) {

bool left = isScramble(s1.substr(0, i), s2.substr(len - i, i));

bool right = isScramble(s1.substr(i, len - i),

s2.substr(0, len - i));

if (left && right) {

return true;

}

}

}

return false;

}