# HackerRank Day 9 Solution in Python: Recursion

Today we will see the HackerRank Day 9 Solution in Python. The problem is named Recursion which is part of 30 Days of code on HackerRank. Let’s get started!

## Day 9: Recursion Problem statement

We have to write the logic for factorial using recursion in the factorial function

Sample Input

``3``

Sample Output

``6``

Explanation: The factorial of 3 is 6(3*2*1)

You can solve the problem here.

## HackerRank Day 9 Solution in Python

```#!/bin/python3

import math
import os
import random
import re
import sys

# Function to find the factorial
def factorial(n):

if (n==1):
return n
else:
return n*factorial(n-1)

if __name__ == '__main__':
fptr = open(os.environ['OUTPUT_PATH'], 'w')
n = int(input())
result = factorial(n)
fptr.write(str(result) + '\n')
fptr.close()```

## Code Explanation

• First, get the input from the user
• Then in the factorial function write the logic to find the factorial using recursion
• That is if the number is n, then return 1
• Else recursively call the function by n*factorail(n-1) to get the factorial of the given number 