Python Program : Factorial of a given number by using recursive

Let’s write a Python program to find the factorial of a given number using recursive method.

A Factorial is the multiplication of a number with every number less than that considered number in a sequential order till 1.

For Instance, Let’s consider a positive integer k. The factorial of k is denoted as k!

k! = k * (k-1) * (k-2) * (k-3) * ……….. * 1

For Example :

7! = 7 * 6 * 5 * 4 * 3 * 2 * 1 = 5040

A Recursive Function is a function which calls itself again and again till it get its desired result.

IMPLEMENTATION :

def recur_factorial(l):
    if l == 1:
        return l
    else:
        return l * recur_factorial(l - 1)
n = 5
if n < 0:
    print("Invalid Input")
elif n == 0:
    print("The Factorial of 0 is 1")
else:
    print("The Factorial of", n, "is", recur_factorial(n))

OUTPUT :

Number : 6
Factorial : 720

Time Complexity : O(n)

Space Complexity : O(n)