N! HDU 1042

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

 

 

思路：大数相乘，用数组来存放数字，存放的最大数字为9999，超过了就进位

#include <stdio.h>
#define N 10000
int main()
{
    long int a[10000]={0};
    long int i,n,k=1,j;
    for(i=1;i<N;i++)
    {
        a[i]=0;
    }
    a[0]=1;
    while(scanf("%d",&n)!=EOF)
    {
        if(n==1)
        {
            printf("1");
            printf("\n");
            continue;
        }

        for(i=2;i<=n;i++)
        {
            for(j=0;j<k;j++)
            {
                a[j]*=i;
            }
            for(j=0;j<k;j++)
            if(a[j]>N)
            {
                a[j+1]+=a[j]/N;
                  a[j]%=N;
            }
            if(a[k]>0)
                k++;
        }
        printf("%d",a[k-1]);
        for(i=k-2;i>=0;i--)
        {
            printf("%04d",a[i]);
        }

        k=1;
        for(i=1;i<N;i++)
        {
            a[i]=0;
        }
        a[0]=1;
        printf("\n");
    }


    return 0;
}