题解 | #与7无关的数#

#include <iostream>
#include <cstdio>

using namespace std;

bool seven(int n){
    if(n%7 == 0){
        return true;
    }
    else{
        while(n!=0){
            if(n%10 == 7){
                return true;
            }
            n /= 10;
        }
    }
    return false;
}

int main(){
    int n;
    while(scanf("%d",&n)!=EOF){
        int sum = 0;
        for(int i = 1; i<=n; i++){
            if(!seven(i)){
                sum += i*i;
            }
        }
        printf("%d\n",sum);
    }
    
   
    
}