Fixes #276 (#1982)

* factorial using recrusion

* Update Factorial.py

Author: aj7tt

Code/Python/Factorial.py

@@ -0,0 +1,31 @@
+'''
+Factorial function instruct to multiply all whole number from input number down to 1.
+The formula for n factorial can be defined as n! = n×(n−1)!
+Factorial zero is defined as equal to 1
+'''
+
+    #This is a recursive function to find the factorial of an integer
+def factorial(num):
+    if num == 0:
+        return 1
+    else:
+        temp = factorial(num-1)
+        return num * temp
+    
+num = int(input("Input: "))
+
+print('Output:',factorial(num))
+
+'''
+    Test cases:
+    Input: 7
+    Output: 5040
+    
+    Input: 0
+    Output: 1
+
+    Time complexity: O(n)
+    Space Complexity: O(1)
+
+'''    
+