Submission

Score: 0

User: APNICHANAN

Problemset: ตรวจบัตรเครดิต

Language: c

Time: 0.003 second

Submitted On: 2025-09-27 09:23:08

#include <stdio.h>
#include <string.h>
int main()
{
    char num[200];
    int sum = 0, a, b;
    scanf("%s", num);
    if (strlen(num) > 16)
    {
        printf("no");
        return 0;
    }
    for (int i = 0; i < 15; i++)
    {
        a = num[i] - 48;
        if (i % 2 == 0)
        {
            if (a < 5)
            {
                sum += a * 2;
            }
            else if (a >= 5)
            {
                sum += ((a - (a % 10)) / 10) + (a % 10);
            }
        }
        else
        {
            sum += a;
        }
    }
    if (10 - (sum % 10) % 10 == num[15] - 48)
        printf("yes");
    else
        printf("no");
}