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

题目意思很简单，求N的阶乘，因为到10000显然要用大数做，

个人感觉大数的题用JAVA做比较好，毕竟写起来比较省时间。

代码：

import java.util.Scanner;
import java.math.*;
public class Main {
	public static void main(String[] args) {
		Scanner cin = new Scanner(System.in);
		while(cin.hasNext()){
                      int  a=cin.nextInt();
                      BigInteger b=new BigInteger("1");
                      for(int i=1;i<=a;i++)
                      {
                        BigInteger num = new BigInteger(i+"");
                        //把整数变成大数的一个比较巧妙的方法
                        b=b.multiply(num);
		      }
                   System.out.println(b.toString());
                   System.gc();
	       }
    }
}