Submission

Score: 100

User: herespeed

Problemset: ตรวจบัตรเครดิต

Language: cpp

Time: 0.005 second

Submitted On: 2026-10-14 10:47:45

#include <bits/stdc++.h>
using namespace std;
// 4n+3(n-1)(n)
int main(){
	string t;
	int sum=0;
	cin>>t;
	int n=t.size();
	int lastdigit=t[n-1]-'0';
	 
	bool evendi = true; 
	for(int i=n-2;i>=0;--i){
		int digit=t[i]-'0';
		
		if(evendi){
			digit*=2;
			if(digit>9) digit-=9;	
		}
		sum+=digit;
		evendi = !evendi;
	}
	if((10-sum%10)%10==lastdigit){
	cout<<"yes";
	} 
	else cout<<"no";
}