题解 | #与7无关的数#

# include<stdio.h>
int judge(int h) {
    if (h % 7 == 0)
        return 0;
    while (h) {
        int t = h % 10;
        if (t == 7)
            return 0;
        h = h / 10;

    }
    return 1;

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

            if (judge(i)) {
                sum += i * i;


            }
        }

        printf("%ld", sum);

    }



}