过样例 但0分 求调

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

const int MAX=1e5+5;
int t,num[MAX],n,a,len=1,cnt;

void empty(){
    for (int i=0;i<len;i++) num[i] = 0;
    num[0]=1;
    len=1;
    cnt=0;
}

int main(){
    cin>>t;

    for (int i=0;i<t;i++){
        empty();
        cin>>n>>a;
        for (int j=2;j<=n;j++){
            for (int k=0;k<len;k++) num[k] *= j;
            int k=0;
            while (true){
                num[k+1] += num[k]/10;
                num[k] %= 10;
                if (num[++k] == 0) break;
            }
            len = k;
        }

        for (int j=0;j<len;j++) if (num[j] == a) cnt++;
        cout<<cnt<<endl;
    }

    return 0;
}