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;
    }
};