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[] = {, , , , , , , , , };
 
int rec(int x) {
    int res = ;
    while(x) {
        res += num[x % ];
        x /= ;
    }
    return res;
}
 
int main() {
    scanf("%d%d", &N, &K);
    M = N / K;
    M = M -  - rec(N);
 
    int ans = ;
    for(int i = ; i <= N / ; i ++) {
        int a = rec(i);
        int b = rec(N - i);
        if(a + b == M)
            ans ++;
    }
 
    printf("%d\n", ans);
    return ;
}