Python 알고리즘_팩토리얼

# factorial_algorithm_1, 계산복잡도 : O(n)
def factorial(n):
    result = 1
    for i in range(2, n + 1):
        result *= i
    return result

# factorial_algorithm_2, 계산복잡도 : O(n)
def factorial2(n):
    if n < 1: # 종료 조건
        return 1
    return n * factorial2(n - 1)

# factorial_algorithm_2, 계산복잡도 : O(n)
def factorial_2(n):
    return n * factorial_2(n - 1) if n > 1 else 1