题解 | #与7无关的数#

#include <iostream>
using namespace std;
int test(int num){
	while (num != 0 ){
		int x = num%10;
		num = num / 10;
		if (x == 7) return 0;
	} 
	return  1 ;
}
int main() {
	int a;
	while (cin >> a) { // 注意 while 处理多个 case
		int sum = 0 ;
		
		for ( int i = 0 ; i <= a ; i++) {
			if (i%7 != 0 && test(i) )
				sum+=i*i;
		}
		cout << sum  << endl;
	}
	
}
// 64 位输出请用 printf("%lld")