LeetCode: 344. Reverse String

051102

题目

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"]

我的解题思路

这道题是要求char字符的逆，这时候把头和尾对应的元素交换就好了。

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