杭电1042（N!）

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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

c代码实现：

#include<stdio.h>
#include<string.h>
int main ()
{
    int t,max,n,c,i,j,a[90001];
    while (scanf("%d",&n)==1)
    {
        memset(a,0,sizeof(a));
        a[0]=1;max=1;
        for(i=1;i<=n;i++)
        {
            c=0;
            for(j=0;j<max;j++)
            {
                a[j]=a[j]*i+c;
                c=a[j]/10000;
                a[j]=a[j]%10000;
                if(c&&max<=j+1)
                max++;
            }
        }
        printf("%d",a[max-1]);
        for(j=max-2;j>=0;j--)
             printf("%04d",a[j]);
        printf("\n");
    }
    return 0;
}

java代码实现：

import java.math.BigInteger;
import java.util.Scanner;
class Main{
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		while(sc.hasNext()){
			int n=sc.nextInt();
			BigInteger p=BigInteger.ONE;
			for(int i=2;i<=n;i++){
				p=p.multiply(BigInteger.valueOf(i));
			}
			System.out.println(p);
		}
	}
}