Computer Science – 12.3 Program Testing and Maintenance | e-Consult

Error Identification: The primary error lies in the range(n) function within the for loop. range(n) generates a sequence of numbers from 0 up to (but not including) n. Therefore, the loop iterates n times, but i will take on values from 0 to n-1. This means the factorial is calculated incorrectly.

Effect on Output: The code calculates the product of 1 * 0 * 1 * 2 * ... * (n-1). This will always result in 0, regardless of the input n. The factorial of a non-negative integer n is defined as n! = n * (n-1) * (n-2) * ... * 1. The current code fails to include the multiplication by n itself.

Example: If the input is 5, the expected output is 5! = 5 * 4 * 3 * 2 * 1 = 120. The current code will output 0.

Corrected Code:

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