{C++} 문자열 겹쳐쓰기

#include <iostream>
#include <string>
#include <vector>

using namespace std;

string solution(string my_string, string overwrite_string, int s) {
    string answer = "";
    int num = overwrite_string.size();
    int index = 0;
    for(int i = s ; i < num + s; i++){
        my_string[i] = overwrite_string[index];
        index++;
    }
    answer = my_string;
    cout << answer;
    return answer;
}

#include <string>
#include <vector>

using namespace std;

string solution(string my_string, string overwrite_string, int s) {
    string answer = "";
    answer = my_string.replace(s,overwrite_string.size(),overwrite_string);
    return answer;
}