Leetcode 344. 反转字符串(Reverse string)
题目链接🔗
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
思路
定义双指针，指向两端。使用for循环交换两指针指向的位置字符即可。
代码实现
class Solution {
public void reverseString(char[] s) {
for(int i = 0, j = s.length - 1; i < j;i++,j--) {
char temp = s[i];
s[i] = s[j];
s[j] = temp;
}
System.out.println(s.toString());
}
}