C++(씨쁠쁠)(cplusplus)-백준(baekjoon)(BaekJoon)코딩 10824번:네 수 답

#include <iostream>
#include <string>
using namespace std;
int main() {
    string a, b, c, d;
    long long ans=0,xs,ys;
    cin >> a >> b >> c >> d;
    string x = a + b;
    string y = c + d;
    xs = x.size();
    ys = y.size();
    for (int i = 0; i < xs; i++)
    {
        long long cnt = 1;
        for (int j = 1; j < xs - i; j++)
            cnt *= 10;
        ans += (x[i] - '0')*cnt;
    }
    for (int i = 0; i < ys; i++)
    {
        long long cnt = 1;
        for (int j = 1; j < ys - i; j++)
            cnt *= 10;
        ans += (y[i] - '0')*cnt;
    }
    cout << ans <<'\n';
}