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

var reverseString = function(s) {
    const n = s.length;
    for (let left = 0, right = n - 1; left < right; ++left, --right) {
        [s[left], s[right]] = [s[right], s[left]];
    }
};