Submission

Score: 100

User: wasupum

Problemset: ตรวจบัตรเครดิต

Language: c

Time: 0.002 second

Submitted On: 2025-10-05 15:23:11

#include <stdio.h>

int main(void){
    char cred[20];
    scanf("%16s",cred);
    
    int num, sum = 0;
    for(int i = 14 ; i >= 0 ; i--){
        num = cred[i] - '0';
        if(i % 2 == 0){
            num *= 2;
            while(num){
                sum += num % 10;
                num /= 10;
            }
        }
        else sum += num;
    }
    
    int check =  (10 - (sum % 10)) % 10;
    if(check == cred[15] - '0') printf("yes\n");
    else printf("no\n");
    
    return 0;
}