344. Reverse String E

Q:

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

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

A:

class Solution {
public:
    void reverseString(vector<char>& s) {
        int i =0, j = s.size()-1;
        while(i<j){
            swap(s[i],s[j]);
            ++i;
            --j;
        }
    }
};