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 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
分析解答
题目不让使用额外的数组分配空间,只能原地操作。
那就要双指针交换了。来呗,弄!😎
js
/**
* @param {character[]} s
* @return {void} Do not return anything, modify s in-place instead.
*/
var reverseString = function (s) {
let l = 0
let r = s.length - 1
while (l < r) {
[s[l], s[r]] = [s[r], s[l]]
l++
r--
}
};