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/**
* @param {character[]} s
* @return {void} Do not return anything, modify s in-place instead.
*/
// api 解法
var reverseString = function(s) {
return s.reverse()
};
// 常规双指针解法
// 规律:s[i]=s[length-1-i]
var reverseString = function(s) {
let left =0;
let right = s.length-1;
while(left<=right){
// 交换左右两个指针指向的元素
[s[left],s[right]]= [s[right],s[left]]
// 两个指针同时靠近
left++;
right--;
}
return s;
};