leetcode.字符串.344反转字符串-Java

1. 具体题目

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"]

2. 思路分析

双指针，首尾交换

3. 代码

 1 public void reversestring(char[] s) {
 2         int left = 0;
 3         int right = s.length - 1;
 4         while(left < right){
 5             char temp = s[left];
 6             s[left] = s[right];
 7             s[right] = temp;
 8             left++;
 9             right--;
10         }
11     }