Factorial of large numbers bjfu1005 java实现大数阶乘

描述

Factorial, as we all know, is the product of all the positive integers from one up to and including a given integer. For example, factorial zero is assigned the value of one; factorial four is 1 × 2 × 3 × 4. Symbol: N! The N is the given integer. But it is hard to calculate the factorial when the N is large. Ben wrote a program to calculate N!(N<10000) when he was in grade one. So try it!

输入

The input consists of multiple test cases. One N (0<=N<=10000,integer) in a line for each test case. Process to the end of file.

输出

For each test case, print the value of N! in a single line.

样例输入

5
10
20
100

样例输出

120
3628800
2432902008176640000
93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000

import java.math.BigInteger;import java.util.Scanner;public class Main {public static void main(String args[]){Scanner cin=new Scanner(System.in);int i;while (cin.hasNext()){i=cin.nextInt();getBigFactorial(i);}cin.close();}public static void getBigFactorial(int n) {if (n==0) System.out.println("0");BigInteger result=new BigInteger("1");for (;n>0;n--) result=result.multiply(new BigInteger(n+""));System.out.println(result);}}

我的症结还在于，不会熟练的在int和Biginteger之间转换。。