Write a factorial function that takes a positive integer, N as a parameter and prints the result of N! ( N factorial).

factorial.java

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
    public static int factorial(int n)//factorial method
        {
            if (n == 0)
            {
                return 1;
            }else if (n < 1)
                {
                return -1;
            }else 
                {
                return n * factorial(n -1);
            }
        
    }

    public static void main(String[] args) {
       Scanner input = new Scanner(System.in);
        // System.out.println("Enter number to factorize ");
         int n = input.nextInt();
         System.out.println(factorial(n) );
    }
}