杭电1042

        一道大数阶乘的题，刚开始写了个程序，tle，，，后来稍微优化了一下，跑了1500多ms，，，据说还可以优化很多，，算法真的是博大精深啊。。。题目：

Given an integer N(0 ≤ N ≤ 10000), your task is to calculate N!

 

Input

One N in one line, process to the end of file.

Output

For each N, output N! in one line.

 

 

Sample Input

   
   
   
   

    
    
    
    1
2
3
   
   
   
   

 

 

Sample Output

   
   
   
   

    
    
    
    1
2
6
   
   
   
   

 

ac代码：

#include <iostream>
using namespace std;
int main()
{
  int n;
  while(cin>>n)
  {
	  int a[50000]={0},i,j,digit=1;
	  a[0]=1;
	  for(i=2;i<=n;++i)
	  {
	    int count;
		for(j=1,count=0;j<=digit;++j)
		{
		  int s=a[j-1]*i+count;
		  a[j-1]=s%10;
		  count=s/10;
		}
		while(count)
		{
		  a[++digit-1]=count%10;
		  count/=10;
		}
	  }
	  for(i=digit;i>=1;i--)
	  {
	    cout<<a[i-1];
	  }
	  
	  cout<<endl;
  }
  return 0;
}

我再看看还能怎么优化