Extra Long Factorials || JAVA || HackerRank

Problem No. 1

Max Score:

20

Difficulty: 

Medium

You are given an integer . Print the factorial of this number.

Input
Input consists of a single integer , where .

Output
Print the factorial of .

Example
For an input of , you would print .

Note: Factorials of  can't be stored even in a  long long variable. Big integers must be used for such calculations. Languages like Java, Python, Ruby etc. can handle big integers, but we need to write additional code in C/C++ to handle huge values.

We recommend solving this challenge using BigIntegers.

Solution in JAVA:

import java.io.*;

import java.util.*;

import java.math.*;

public class Solution {

    static void run(int a) {

        int i=1;

        BigInteger fact=BigInteger.valueOf(1);

        while(i<=a){

            fact=fact.multiply(BigInteger.valueOf(i));

            i++;

        }

        System.out.println(fact);

    }

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);

        int n = in.nextInt();

        run(n);

        in.close();

    }

}