LeetCode344.反转字符串

题目

344.反转字符串

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。

实例1：

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

实例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

代码

思路：字符串反转和链表反转类似，使用双指针法

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