HDU 1042 N!

題目描述：

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

解題報告：

1：大數相乘，直接上java

代碼：

import java.math.BigInteger;
import java.util.Scanner;

public class Main{

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n;
        while(scanner.hasNext()){
            n = scanner.nextInt();
            BigInteger ans = new BigInteger("1");
            for (int i = 1; i <= n; i++) {
                ans = ans.multiply(BigInteger.valueOf(i));
            }
            System.out.println(ans);
        }
    }
}