Submission

Score: 100

User: Peam

Problemset: ตรวจบัตรเครดิต

Language: c

Time: 0.001 second

Submitted On: 2025-09-30 18:46:18

#include <stdio.h>

int main(){
    char card[17];
    scanf("%s", card);

    int sum = 0;
    for(int i = 0; i < 15; i++){
        if(i % 2 == 0){
            if(card[i] > '4'){
                if(card[i] == '5') sum+=1;
                if(card[i] == '6') sum+=3;
                if(card[i] == '7') sum+=5;
                if(card[i] == '8') sum+=7;
                if(card[i] == '9') sum+=9;
            }
            else{
                sum+=(card[i] - '0') * 2;
            }
        }
        else{
            sum+=card[i] - '0';
        }
    }

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

}