LeetCode-344 反转字符串

题目

https://leetcode-cn.com/problems/reverse-string/

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：

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

示例 2：

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

---

我的AC

class Solution(object):
    def reverseString(self, s):
        """
        :type s: List[str]
        :rtype: void Do not return anything, modify s in-place instead.
        """
        ls = len(s)
        for i in range(ls/2):
            s[i], s[ls-1-i] = s[ls-1-i], s[i] 

AC版本2

class Solution(object):
    def reverseString(self, s):
        """
        :type s: List[str]
        :rtype: void Do not return anything, modify s in-place instead.
        """
        s[::] = s[::-1]

---

小结

一个错误的版本：

class Solution(object):
    def reverseString(self, s):
        s = s[::-1]

• 这里 = 左边的 s 其实是创建了一个新的内存空间，测试输入的内存空间并没有发生改变