Leetcode 344. Reverse String

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

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

解法一：直接用reverse函数

class Solution {
public:
    string reverseString(string s) {
        reverse(s.begin(), s.end());
        return s;
        
    }
};

解法二：利用两个指针，首尾元素互换

class Solution {
public:
    string reverseString(string s) {
        int len = s.length();
        for(int i = 0, j = len - 1; i < j; i++, j--){
            swap(s[i], s[j]);
        }
        return s;
        
    }
};