Submission

Score: 100

User: cheetah

Problemset: ตรวจบัตรเครดิต

Language: cpp

Time: 0.004 second

Submitted On: 2026-10-06 19:44:16

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

int main () {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    string s;
    cin >> s;
    int sum = 0;

    for (int i = 14; i >= 0; --i) {
        if (i % 2 == 0) {
            if (2 * (s[i] - '0') > 9) {
                sum += (2 * (s[i] - '0') - 2 * (s[i] - '0') % 10) / 10 + 2 * (s[i] - '0') % 10;
            }
            else {
                sum += 2 * (s[i] - '0');
            }
            
            // cout << "1 = " << 2 * (s[i] - '0') << "\n";
        }
        else {
            sum += s[i] - '0';
            // cout << "2 = " << s[i] - '0' << "\n";
        }
    }

    if ((10 - (sum % 10)) % 10 == s[15] - '0') {
        cout << "yes";
    }
    else {
        cout << "no";
    }

    return 0;
}