牛客OI周赛7-提高组

https://ac.nowcoder.com/acm/contest/371#question

A.小睿睿的等式

#include <bits/stdc++.h>
using namespace std;

int N, K, M;
int num[11] = {6, 2, 5, 5, 4, 5, 6, 3, 7, 6};

int rec(int x) {
    int res = 0;
    while(x) {
        res += num[x % 10];
        x /= 10;
    }
    return res;
}

int main() {
    scanf("%d%d", &N, &K);
    M = N / K;
    M = M - 4 - rec(N);

    int ans = 0;
    for(int i = 1; i <= N / 2; i ++) {
        int a = rec(i);
        int b = rec(N - i);
        if(a + b == M)
            ans ++;
    }

    printf("%d
", ans);
    return 0;
}