Submission

Score: 100

User: Hxluk.ka

Problemset: ตรวจบัตรเครดิต

Language: c

Time: 0.002 second

Submitted On: 2025-10-11 09:40:43

#include <stdio.h>
#include <stdlib.h>

struct Node {
	int data;
	struct Node *next;
};

struct Node* createNode(int val) {
	struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
	if (newNode == NULL) {printf("Allocated fail"); return NULL;}

	newNode->data = val;
	newNode->next = NULL;

	return newNode;
}

struct Node* pushNode(struct Node *node, int val) {
	if (node == NULL) {printf("Can't push to null node\n"); return NULL;}
	struct Node* new = createNode(val);
	node->next = new;
	return new;
}

int main() {
	char creds[17];
	scanf("%s", creds);
	struct Node *head = createNode(0);
	struct Node *tail = head;

	for (int i = 0; i < 15; i++) {
		int digit = creds[i] - '0';
		if (i%2==0)digit *= 2;
		
		if (digit > 9) {

			tail = pushNode(tail, digit/10);
			tail = pushNode(tail, digit%10);
			continue;
		}
		else tail = pushNode(tail, digit);
	}

	head = head->next;
	int sum = 0;
	for (int i = 0; head!=NULL; i++) {
		int val = head->data;
		tail = head;
		head = head->next;
		free(tail);
		sum+=val; 
	}

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