Leetcode 344. 反转字符串

地址 https://leetcode-cn.com/problems/reverse-string/

编写一个函数，其作用是将输入的字符串反转过来。输入字符串以字符数组 s 的形式给出。
不要给另外的数组分配额外的空间，你必须原地修改输入数组、使用 O(1) 的额外空间解决这一问题。

示例 1：
输入：s = ["h","e","l","l","o"]
输出：["o","l","l","e","h"]

示例 2：
输入：s = ["H","a","n","n","a","h"]
输出：["h","a","n","n","a","H"]
 

提示：
1 <= s.length <= 105
s[i] 都是 ASCII 码表中的可打印字符

双指针，一个从头一个从尾 将其指向的字符互换，直到两者相遇

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