344.Reverse String

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

Example:
Given s = "hello", return "olleh".

Java(3ms):

public class Solution {
    public String reverseString(String s) {
        if (s.length() <= 1){
             return s ;
         }
        char a[] = s.toCharArray() ;
        int i  = 0 ;
        int j  = s.length() - 1 ;
        while(i < j ){
            char t = a[i] ;
            a[i] = a[j] ;
            a[j] = t ;
            i++ ;
            j-- ;
        }
        return new String(a) ;
    }
}

C++(9ms):

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

C++(9ms):

class Solution {
public:
    string reverseString(string s) {
        if (s == "")
          return s ;
        if (s.length() == 1)
          return s ;
        int i = 0 ;
        int j = s.length() - 1 ;
        while(i < j){
            s[i] = s[i]^s[j] ;
            s[j] = s[i]^s[j] ;
            s[i] = s[i]^s[j] ;
            i++ ;
            j-- ;
        }
        return s ;
    }
};

C++(9ms):

class Solution {
public:
    string reverseString(string s) {
        int len = s.length();
        string ans = "" ;
        for (int i = len - 1 ; i >= 0 ; i--){
            ans += s[i] ;
        }
        return ans ;
    }
};

C++(12ms):

class Solution {
public:
    string reverseString(string s) {
        reverse(s.begin(),s.end()) ;
        return s ;
    }
};

C++(26ms):

class Solution {
public:
    string reverseString(string s) {
        if (s == "")
          return s ;
        if (s.length() == 1)
          return s ;
        string leftString = s.substr(0,s.length()/2) ;
        string rightString = s.substr(s.length()/2,s.length()) ;
        return reverseString(rightString) + reverseString(leftString) ;
    }
};

C++(9ms):

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