Submission

Score: 100

User: Pera

Problemset: ตรวจบัตรเครดิต

Language: cpp

Time: 0.002 second

Submitted On: 2025-03-26 09:36:21

#include <bits/stdc++.h>
using namespace std;

int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);

    string credit;
    cin >> credit;

    int last = credit.back() - '0';

    credit.erase(credit.end() - 1);
    int sum{0};
    for (int i = 0; i < credit.length(); ++i) {
        if (i % 2 != 0) sum += credit[i] - '0';
        else {
            int n = credit[i] - '0';
            n *= 2;
            if (n < 9) sum += n;
            else {
                sum += n % 10;
                n /= 10;
                sum += n;
            }
        }
    }

    // cout << "sum is " << sum << '\n';
    // cout << "last is " << last << '\n';

    if ((10 - (sum % 10)) % 10 == last) cout << "yes" << '\n';
    else cout << "no" << '\n';

}