求助大佬，全wa，不知道哪里出了问题，求助，谢谢大佬

#include<iostream>
#include<algorithm>
#include<cstring>
#include<iomanip>
#include<vector>
#include<cmath>
#include<cctype>
#define IOS std::ios::sync_with_stdio(false);cin.tie(0),cout.tie(0);
#define pi acos(-1);
#include<map>
int t,n,a;
using namespace std;
typedef struct node{

}node;
vector<int>A;
vector<int>mul(vector<int>A,int x){
    vector<int>C;
    int t=0;
    for(int i=A.size()-1;i>=0;i--){
        t+=A[i]*x;
        C.push_back(t%10);
        t/=10;
    }
    if(t)C.push_back(t);
    while(C.size()>1&&C.back()==0)C.pop_back();
    reverse(C.begin(),C.end());
    return C;
}
void ccin(){

}
void work(){

}
int main(){
    IOS;
    cin>>t;while(t--){
        cin>>n>>a;
        A.clear();
        A.push_back(1);
        for(int i=1;i<=n;i++){
            A=mul(A,i);
        }
        int sum=0;
        for(int i=0;i<A.size();i++){
            if(A[i]==a)sum++;
        }
        cout<<sum<<endl;
    }
    return 0;
}