344. 反转字符串

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:

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

示例  2:

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

代码实现: 双指针

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/**
* @param {character[]} s
* @return {void} Do not return anything, modify s in-place instead.
*/
var reverseString = function (s) {
let i = 0;
let j = s.length - 1;
while (i < j) {
[s[i], s[j]] = [s[j], s[i]];
i++;
j--;
}
};