least_common_multiple.py

importunittest
fromtimeitimporttimeit

frommaths.greatest_common_divisorimportgreatest_common_divisor


defleast_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_numiffirst_num>=second_numelsesecond_num
common_mult=max_num
while (common_mult%first_num>0) or (common_mult%second_num>0):
common_mult+=max_num
returncommon_mult


defleast_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
 """
returnfirst_num//greatest_common_divisor(first_num, second_num) *second_num


defbenchmark():
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),
 )


classTestLeastCommonMultiple(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)

deftest_lcm_function(self):
fori, (first_num, second_num) inenumerate(self.test_inputs):
slow_result=least_common_multiple_slow(first_num, second_num)
fast_result=least_common_multiple_fast(first_num, second_num)
withself.subTest(i=i):
assertslow_result==self.expected_results[i]
assertfast_result==self.expected_results[i]


if__name__=="__main__":
benchmark()
unittest.main()