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

一次通过