import unittest from timeit import timeit from maths.greatest_common_divisor import greatest_common_divisor def least_common_multiple_slow(first_num: int, second_num: int) -> int: """ Find the least common multiple of two numbers. Learn more: https://en.wikipedia.org/wiki/Least_common_multiple >>> least_common_multiple_slow(5, 2) 10 >>> least_common_multiple_slow(12, 76) 228 """ max_num = first_num if first_num >= second_num else second_num common_mult = max_num while (common_mult % first_num > 0) or (common_mult % second_num > 0): common_mult += max_num return common_mult def least_common_multiple_fast(first_num: int, second_num: int) -> int: """ Find the least common multiple of two numbers. https://en.wikipedia.org/wiki/Least_common_multiple#Using_the_greatest_common_divisor >>> least_common_multiple_fast(5,2) 10 >>> least_common_multiple_fast(12,76) 228 """ return first_num // greatest_common_divisor(first_num, second_num) * second_num def benchmark(): setup = ( "from __main__ import least_common_multiple_slow, least_common_multiple_fast" ) print( "least_common_multiple_slow():", timeit("least_common_multiple_slow(1000, 999)", setup=setup), ) print( "least_common_multiple_fast():", timeit("least_common_multiple_fast(1000, 999)", setup=setup), ) class TestLeastCommonMultiple(unittest.TestCase): test_inputs = ( (10, 20), (13, 15), (4, 31), (10, 42), (43, 34), (5, 12), (12, 25), (10, 25), (6, 9), ) expected_results = (20, 195, 124, 210, 1462, 60, 300, 50, 18) def test_lcm_function(self): for i, (first_num, second_num) in enumerate(self.test_inputs): slow_result = least_common_multiple_slow(first_num, second_num) fast_result = least_common_multiple_fast(first_num, second_num) with self.subTest(i=i): assert slow_result == self.expected_results[i] assert fast_result == self.expected_results[i] if __name__ == "__main__": benchmark() unittest.main()