Factorial of big number in java

The factorial of the integer , written , is defined as:

Calculate and print the factorial of a given integer.

For example, if , we calculate  and get .

Function Description

Complete the extraLongFactorials function in the editor below. It should print the result and return.

extraLongFactorials has the following parameter(s):

• n: an integer

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.

Input Format

Input consists of a single integer 

Constraints

Output Format

Print the factorial of .

Sample Input

Sample Output

Explanation

25! = 25 x 24 x 23 x ...........3 x 2 x 1

Solution:- 

import java.io.*;

import java.math.*;

import java.security.*;

import java.text.*;

import java.util.*;

import java.util.concurrent.*;

import java.util.function.*;

import java.util.regex.*;

import java.util.stream.*;

import static java.util.stream.Collectors.joining;

import static java.util.stream.Collectors.toList;

class FactorialDemo {

    public static void extraLongFactorials(int n) {

    BigInteger result = new BigInteger(""+n);

    for (int i = 1; i<n ; i++)

    {

        result = result.multiply(BigInteger.valueOf(n-i));

    }

    System.out.println(result);

    }

}

public class Solution {

    public static void main(String[] args) throws IOException {

        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

        int n = Integer.parseInt(bufferedReader.readLine().trim());

        FactorialDemo.extraLongFactorials(n);

        bufferedReader.close();

    }

}