reverse-string

Reverse String – LeetCode 344

Problem

Description

Write a function that takes a string as input and returns the string reversed.

Example

Given s = “hello”, return “olleh”.

Answer

Original

Code

class Solution {
public:
    string reverseString(string s) {
        return string(s.rbegin(),s.rend());
    }
};

思路

简单的逆向，时间复杂度$O(n)$，空间复杂度$O(1)$。
耗时$11$ ms，排名$81.34\%$

Better

思路

等价版本
耗时$11$ ms，排名$81.34\%$

Code

class Solution {
public:
    string reverseString(string s) {
        int i = 0, j = s.size() - 1;
        while(i < j){
            swap(s[i++], s[j--]); 
        }
        
        return s;
    }
};