1.描述

Write a function that takes a string as input and returns the string reversed.

Example:
Given s = "hello", return "olleh".

2.分析

3.代码

class Solution {
public:
    string reverseString(string s) {
        if (s.size() == 0 || s.size() == 1) return s;
        int low = 0, high = s.size() - 1;
        while (low < high) {
            swap(s[low++], s[high--]);
        }
        return s;
    }
};