[C++]백준 11720번:숫자의 합

https://www.acmicpc.net/problem/11720

#include <iostream>

#include <string>

using namespace std;

int main() {

string N;

int size;

cin >>size>> N;

int sum = 0;

for (int i = 0; i < size; i++) {

string tmp = N.substr(i,1);

sum += stoi(tmp);

}

cout << sum;

}