Submission

Score: 0

User: SushiCodelnw

Problemset: ตรวจบัตรเครดิต

Language: c

Time: 0.002 second

Submitted On: 2025-09-26 08:29:11

#include <stdio.h>
#include <string.h>

int main() {
    char crad[17];
    int sum = 0;
    fgets(crad, 17, stdin);
    for (int i = 0; i < strlen(crad) - 1; i++) {
        int num = crad[i] - '0';
        if (i % 2 == 0) {
            if (num < 5) sum += num * 2;
            else switch (num) {
                case 5: sum += 1; break;
                case 6: sum += 3; break;
                case 7: sum += 5; break;
                case 8: sum += 7; break;
                case 9: sum += 9; break;
            }
        }
        else sum += num;
    }
    if (10 - (sum % 10) % 10 == crad[strlen(crad) - 1] - '0') printf("yes\n");
    else printf("no\n");
    return 0;
}