3.2 Homework

# Recursion Hack - Factorial Function
def factorial(n):
    """Calculates the factorial of a non-negative integer n."""
    if not isinstance(n, int) or n < 0:  # Handle invalid input
        return "Error: Factorial is only defined for non-negative integers."
    elif n == 0 or n == 1:  # Base cases
        return 1
    else:
        return n * factorial(n - 1)  # Recursive call

# Example Usage
number = 11
result = factorial(number)

# Display the result with a custom message
if isinstance(result, int):
    print(f"The factorial of {number} is {result}.")
else:
    print(result)

# Iterating Over a List Hack
numbers = [1, 2, 3, 4, 5]
for number in numbers:  # Print each number in the list
    print(number)

# Iterating Over a List with Colors Hack
colors = ["red", "blue", "green", "yellow"]
for color in colors:  # Print each color in the list
    print(color)

# Breaking Loops Hack
numbers = [1, 2, 3, 4, 5]
for number in numbers:
    if number == 3:
        continue  # Skip the number 3
    elif number == 5:
        break  # Stop the loop when 5 is encountered
    print(number)

The factorial of 11 is 39916800.
1
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