README.md

344. 反转字符串

English Version

题目描述

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 char[] 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。

你可以假设数组中的所有字符都是 ASCII 码表中的可打印字符。

 

示例 1：

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

示例 2：

输入：["H","a","n","n","a","h"]
输出：["h","a","n","n","a","H"]

解法

Python3

class Solution:
    def reverseString(self, s: List[str]) -> None:
        """
        Do not return anything, modify s in-place instead.
        """
        s[:] = s[::-1]

Java

class Solution {
    public void reverseString(char[] s) {
        int n;
        if (s == null || (n = s.length) < 2) return;
        int i = 0, j = n - 1;
        while (i < j) {
            char t = s[i];
            s[i] = s[j];
            s[j] = t;
            ++i;
            --j;
        }
    }
}

...