Factorial for Counting Outcomes

Problem

Compute n! iteratively as 1 * 2 * ... * n.

Return 1 when n = 0, since the empty product is 1, and 0 for negative n.

Hint

The empty product is 1, and factorials are never defined for negative integers here.

case 1

in: [5]

expected: 120

case 2

in: [0]

expected: 1

case 3

in: [1]

expected: 1

case 4

in: [10]

expected: 3628800

case 5

in: [-3]

expected: 0

Starter codePython

def factorial(n):
    # Your code here
    pass

5 test cases · run your code against them in the editor