# 能看懂不
```#include<bits/stdc++.h>
using namespace std;
int main()
{
int i,a[1005]={0},b[1005]={0},n,j;
scanf("%d", &n);
a[0]=b[0]=1;
for (int i=2;i<=n;i++)
{
for (j=0;j<101;j++)
b[j]*=i;
for (j=0;j<101;j++)
if (b[j]>9)
{
b[j+1] += b[j]/10;
b[j]%=10;
}
for (j=0;j<100;j++)
{
a[j]+=b[j];
if (a[j]>9)
{
a[j+1] += a[j]/10;
a[j]%=10;
}
}
}
for (i=100;i>=0&&a[i]==0;i--);
for (j=i;j>=0;j--)
printf("%d", a[j]);
return 0;
}
by 09rxq @ 2024-03-01 13:24:44