2020-03-10 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。 说明:

• 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: 输入: ["h","e","l","l","o"] 输出: ["o","l","l","e","h"] 输入: ["H","a","n","n","a","h"] 输出: ["h","a","n","n","a","H"] 题解: 思路1： 双指针 左右对称结构赋值  

/**
 * @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--;
  }
  return s;
};