Likou Question of the Day - Day 46 - 344. Reverse Strings

2022.8.2 Did you write the questions today?

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Title:

Write a function that reverses the input string.The input string is given as a character array s.

Don't allocate extra space for another array, you have to modify the input array in place, using O(1) extra space to solve this problem.

Analysis:

Given a vector array of char, no new space memory can be generated to reverse the original string.

Ideas: The simplest idea: a reverse!!!Of course, that makes no sense.So our idea is:

Use two pointers, one from the left and one from the right, and use a temp as an intermediate variable.Swap two values ​​until left >= right.

Analysis:

1. Double pointer

class Solution {public:void reverseString(vector& s) {int left = 0;int right = s.size() - 1;char temp;while (left < right){temp = s[left];s[left] = s[right];s[right] = temp;left++;right--;}}};

2.reverse

class Solution {public:void reverseString(vector& s) {reverse(s.begin(),s.end());}};