@[1_1_1_1_1_1_](/user/965334)
```cpp
#include <iostream>
#include <cstring>
using namespace std;
int f[5001];
void mmultip(int a[], int c) {
int jw = 0;
for (int i=1; i<=5000; ++i) {
a[i] = a[i] * c + jw;
jw = a[i] /10;
a[i] %= 10;
}
}
int countA (int n, int a) {
int i, count = 0;
memset(f, 0, sizeof(f));
f[1] = 1;
for (i=2; i<=n; ++i)
mmultip(f, i);
for (i=5000; f[i] == 0; --i);
for (; i>=1; --i)
if (f[i] == a)
++count;
return count;
}
int main() {
int t;
cin >> t;
int n[t], a[t], ans[t];
for (int i=0; i<t; ++i)
cin >> n[i] >> a[i];
for (int i=0; i<t; ++i)
ans[i] = countA(n[i], a[i]);
for (int i=0; i<t; ++i)
cout << ans[i] << endl;
return 0;
}
```
求关
顺便关注一下我的
[百度账号](https://author.baidu.com/home?from=bjh_article&app_id=1778195646412935)
by Cy_AlphaKai_CCF @ 2023-11-08 20:34:43
@[2931Coupler](/user/779036) 看不懂
by 1_1_1_1_1_1_ @ 2023-11-08 21:41:12