Calculate Factorial - codepath/compsci_guides GitHub Wiki

Unit 1 Session 1 (Click for link to problem statements)

U-nderstand

Understand what the interviewer is asking for by using test cases and questions about the problem.

• Will n always be a positive integer?
  • Yes.

P-lan

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Create a function that calculates the factorial of a positive integer n.

1) Create and initialize a variable to store the result
2) For each number from 1 to n, multiply the result by that number
3) Return the result variable

⚠️ Common Mistakes

• Make sure your result variable is correctly initialized! What is the smallest possible result for our factorial function?

I-mplement

def factorial(n):
	result = 1
	for num in range(1, n + 1):
		result *= num
	return result