leetcode

0 class Solution {

1 public:

2 string shortestPalindrome(const string &s) const {

3 const int n = s.size();

4 int i = 0, j = n - 1;

5

6 while (j >= 0) {

7 if (s[i] == s[j]) i++;

8 j--;

9 }

10

11 if (i == n) return s;

12 string remain = s.substr(i), rev = remain;

13 reverse(rev.begin(), rev.end());

14

15 return rev + shortestPalindrome(s.substr(0, i)) + remain;

16 }

17 };