class Solution {
public:
void reverseString(vector<char>& s) {
int i=0;
int j=s.size()-1;
while(i<j)
{
swap(s[i],s[j]);
i++;
j--;
}
}
};
//Runtime: 20 ms, faster than 76.31% of C++ online submissions for Reverse String.
//Memory Usage: 23.3 MB, less than 38.31% of C++ online submissions for Reverse String.