From 750c1ccc62064d5d0ed9351cb96c45626867d35e Mon Sep 17 00:00:00 2001
From: Tithi Joshi <tithijoshi27@gmail.com>
Date: Wed, 4 Feb 2026 12:15:50 +0530
Subject: [PATCH 1/2] fix: handle zero and negative inputs in least common
 multiple

Updated docstrings to clarify LCM function behavior with zero inputs and adjusted expected results in tests.
---
 maths/least_common_multiple.py | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/maths/least_common_multiple.py b/maths/least_common_multiple.py
index a5c4bf8e3625..a92b454adc33 100644
--- a/maths/least_common_multiple.py
+++ b/maths/least_common_multiple.py
@@ -6,7 +6,7 @@
 
 def least_common_multiple_slow(first_num: int, second_num: int) -> int:
     """
-    Find the least common multiple of two numbers.
+    Find the least common multiple (LCM) of two integers.
 
     Learn more: https://en.wikipedia.org/wiki/Least_common_multiple
 
@@ -14,8 +14,13 @@ def least_common_multiple_slow(first_num: int, second_num: int) -> int:
     10
     >>> least_common_multiple_slow(12, 76)
     228
+    >>> least_common_multiple_slow(0, 5)
+    0
     """
-    max_num = first_num if first_num >= second_num else second_num
+    if first_num == 0 or second_num == 0:
+        return 0
+
+    max_num = max(abs(first_num), abs(second_num))
     common_mult = max_num
     while (common_mult % first_num > 0) or (common_mult % second_num > 0):
         common_mult += max_num
@@ -24,14 +29,24 @@ def least_common_multiple_slow(first_num: int, second_num: int) -> int:
 
 def least_common_multiple_fast(first_num: int, second_num: int) -> int:
     """
-    Find the least common multiple of two numbers.
+    Find the least common multiple (LCM) of two integers.
+
+    Uses the relationship between LCM and GCD:
     https://en.wikipedia.org/wiki/Least_common_multiple#Using_the_greatest_common_divisor
-    >>> least_common_multiple_fast(5,2)
+
+    >>> least_common_multiple_fast(5, 2)
     10
-    >>> least_common_multiple_fast(12,76)
+    >>> least_common_multiple_fast(12, 76)
     228
+    >>> least_common_multiple_fast(0, 5)
+    0
     """
-    return first_num // greatest_common_divisor(first_num, second_num) * second_num
+    if first_num == 0 or second_num == 0:
+        return 0
+
+    return abs(
+        first_num // greatest_common_divisor(first_num, second_num) * second_num
+    )
 
 
 def benchmark():
@@ -59,8 +74,9 @@ class TestLeastCommonMultiple(unittest.TestCase):
         (12, 25),
         (10, 25),
         (6, 9),
+        (0, 5),
     )
-    expected_results = (20, 195, 124, 210, 1462, 60, 300, 50, 18)
+    expected_results = (20, 195, 124, 210, 1462, 60, 300, 50, 18, 0)
 
     def test_lcm_function(self):
         for i, (first_num, second_num) in enumerate(self.test_inputs):

From 70ed5a764692a8a8f483df5bc4a1833e0ae17c78 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 4 Feb 2026 06:47:01 +0000
Subject: [PATCH 2/2] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 maths/least_common_multiple.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/maths/least_common_multiple.py b/maths/least_common_multiple.py
index a92b454adc33..9eca5ae97942 100644
--- a/maths/least_common_multiple.py
+++ b/maths/least_common_multiple.py
@@ -44,9 +44,7 @@ def least_common_multiple_fast(first_num: int, second_num: int) -> int:
     if first_num == 0 or second_num == 0:
         return 0
 
-    return abs(
-        first_num // greatest_common_divisor(first_num, second_num) * second_num
-    )
+    return abs(first_num // greatest_common_divisor(first_num, second_num) * second_num)
 
 
 def benchmark():