LeetCode 344. 反转字符串

示例 1：

输入：["h","e","l","l","o"]
输出：["o","l","l","e","h"]
示例 2：

输入：["H","a","n","n","a","h"]
输出：["h","a","n","n","a","H"]

class Solution {
public:
    void reverseString(vector<char>& s) {
        int i = 0, j = s.size()-1;
        char ch;
        while(i < j)
        {
            ch = s[i];
            s[i] = s[j];
            s[j] = ch;
            ++i,--j;
        }
    }
};