LeetCode 344.反转字符串【Java】

• 1.题目
• 2.思路和代码

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。

示例 1：
输入：s = ["h","e","l","l","o"]
输出：["o","l","l","e","h"]

示例 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

双指针交换即可

class Solution {
    public void reverseString(char[] s) {
        int i = 0;
        int j = s.length - 1;
        while(i < j){
            char tmp = s[i];
            s[i] = s[j];
            s[j] = tmp;
            i++;
            j--;
        }
    }
}