Find the Factorial of the Number using Recursion in Java

October 14, 2022

Factorial of a Number using Recursion in Java

Here, in this page we will discuss the program to find the factorial of a number using recursion in Java programming Language. We will discuss various methods to solve the given problem.

Factorial of a Number using Recursion in Java

Method Discussed :

  • Method 1 : Using Recursion
  • Method 2 : Using Iteration.

Let’s discuss them one by one in brief,

Method 1:

  • Call function getFactorial(num)
  • Set base case when num== 0 return 1
  • Other cases return num * getFactorial(num-1);

Time and Space Complexity :

  • Time complexity: O(N)
  • Space complexity: O(1)
  • Auxiliary Space complexity (Function call stack): O(N)
Factorial of Number using Recursion in java
Run 
class Main {
    // method to find factorial of given number
    static int factorial(int n)
    {
        if (n == 0)
            return 1;
 
        return n * factorial(n - 1);
    }
 
    // Driver method
    public static void main(String[] args)
    {
        int num = 5;
        System.out.println("Factorial of " + num  + " is " + factorial(5));
    }
}

Output :

Factorial of 5 is 120

Method 2:

  • Initialize fact = 1
  • If num < 0 : Print Error as we can’t calculate factorial of a negative number
  • Else run a iterative loop in iteration of (i) between [1, num]
  • Set fact = fact * i
  • Print the value of fact.

Time and Space Complexity :

  • Time complexity: O(N)
  • Space complexity: O(1)

Method 2 : Code in Java

Run 
class Main {
 
    // Method to find factorial of the given number
    static int factorial(int n)
    {
        int res = 1, i;
        for (i = 2; i <= n; i++)
            res *= i;
        return res;
    }
 
    // Driver method
    public static void main(String[] args)
    {
        int num = 5;
        System.out.println("Factorial of " + num + " is " + factorial(5));
    }
}

Output :

Factorial of 5 is 120

Fibonacci Series upto nth term

Find the Nth Term of the Fibonacci Series

Factorial of a number

Power of a number

Factor of a number

Strong number

Prime Course Trailer

Related Banners

Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription

Get Prime