#include <iostream>
#define N 50000
using namespace std;
int main()
{
int p[N],i,j,n,k;
 while(scanf("%d",&n)!=EOF)
   {
   k=0;
      for(i=0;i<N;i++)
          p[i]=0;
          p[N-1]=1;
          for(i=1;i<=n;i++)
            {
             int temp_jw=0;
             for(j=N-1;j>=0;j--)
              {
                p[j]=p[j]*i+temp_jw;
                temp_jw=p[j]/10;
                p[j]=p[j]%10;
              }
            }     
    for(i=0;i<N;i++)
        if(p[i]==0&&p[i+1]!=0)
        {
         k=i;
         break;
        }
     for(i=k;i<N;i++)
        cout<<p[i];   
        cout<<endl;     
   }

}

感谢所有回帖者！