22-reverseString-Leetcode

思路：so easy

class Solution {public:    string reverseString(string s) {        int n = s.size();        for(int i=0;i<n/2;++i)        {            char c = s[i];            s[i] = s[n-1-i];            s[n-1-i] = c;        }        return s;    }};