344.Reverse String

题目描述

Write a function that reverses a string. The input string is given as an array of characters char[].

Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

You may assume all the characters consist of printable ascii characters.

Example 1:

Input: [“h”,”e”,”l”,”l”,”o”]
Output: [“o”,”l”,”l”,”e”,”h”]
Example 2:

Input: [“H”,”a”,”n”,”n”,”a”,”h”]
Output: [“h”,”a”,”n”,”n”,”a”,”H”]

我的解法

实现代码

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