第 4 天

双指针

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344. 反转字符串

编写函数的功能是逆转输入的字符串。用字符数组输入字符串s给出形式。

不要给其他数组额外的空间，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"]

class Solution:     def reverseString(self, s: List[str]) -> None:         """         Do not return anything, modify s in-place instead.         """         left = 0         right = len(s)-1         while left<=right:             s[left],s[right] = s[right],s[left]             left  = 1             right -= 1

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557. 反转字符串中的单词 III

给定字符串s，您需要反转字符串中每个单词的字符顺序，并保留空间和单词的初始顺序。

示例 1：

输入：s = "Let's take LeetCode contest" 输出："s'teL ekat edoCteeL tsetnoc" 

示例 2:

输入： s = "God Ding" 输出："doG gniD"

class Solution:     def reverseWords(self, s: str) -> str:         s = s.split(' ')         a , b= '',''         for i in s:             i = list(i)             left = 0             right = len(i)-1             while left <= right:                 i[left], i[right] = i[right], i[left]                 left  = 1                 right -= 1             b  = a.join(i) ' '           return b[:-1]

class Solution(object):     def reverseWords(self, s):         return " ".join(s.split(" ")[:-1]  作者：swants 链接：https://leetcode.cn/problems/reverse-words-in-a-string-iii/solution/python-fan-zhuan-zi-fu-chuan-zhong-dan-ci-si-lu-xi/ 来源：力扣（LeetCode） 作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。