http://acm.nyist.net/JudgeOnline/problem.php?pid=28

连乘

1 import java.io.*; 2 import java.math.BigInteger; 3 import java.util.*; 4  5  6 public class Main { 7     public static void main(String[] args) { 8     Scanner cin=new Scanner(System.in); 9     int n= cin.nextInt();10     BigInteger ans=BigInteger.ONE;11     for(int i=1;i<=n;i++)12         ans=ans.multiply(BigInteger.valueOf(i));13     System.out.println(ans);14      }15 }