Question

In Java please
What happens if you call factorial( with a negative value of n? With a large value of say 35?
Write a recursive function that takes an integer n as its argument and returns ln(n!)

Answer 1

Below is the Java Solution with output screenshot

Code :

import java.util.Scanner;

public class Solution {
    // main method
    public static void main(String[] args) {
        int n;
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a number: ");
        n = sc.nextInt();
        System.out.println("Factorial of " + n + " = " + factorial(n));
    }

    // recursive factorial function
    public static int factorial(int n){
        if(n<=0){
            return 1;
        }
        return n*factorial(n-1);
    }
}

Output :

Case 1: if we call factorial() function with negative value

Answer : The factorial is the product of all positive integers less than or equal to n. Hence we can't calculate factorial of negative numbers. and if we do pass a negative value we will get an error.

Case 2 : pass large number like 35 in factorial function

Factorial of a large number like 35 is a very big number (~10⁴⁰) which can't be stored in integer value because integers can only store values up to 10⁹ range

Hence if we call factorial function with large value i.e factorial(35) then we will get 0 output because of integer overflow.