1042/72 n!

 

Problem Description

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

#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <time.h>
using namespace std;
int a[10001];
int main()
{
    int n,sum,i,j,k;
    while(~scanf("%d",&n))
    {
        k=a[0]=1;sum=0;
        for(i=n;i>1;i--)
        {
            for(j=0;j<k;j++)
            {
                a[j]=a[j]*i+sum;
                sum=a[j]/100000;
                a[j]=a[j]%100000;

            }
            while(sum)
            {
                a[k++]=sum%100000;
                sum=sum/100000;
            }
        }
        cout<<a[k-1];
        for(int i=k-2;i>=0;i--)
        printf("%05d",a[i]);
        cout<<endl;
    }
    return 0;
}

这个题有两个知识点：

1.数值型高精度

2.补零操作（重点）