Merge pull request #134 from WazedKhan/leetcode-16-three-sum-closest

LeetCode #16: 3Sum Closest

Author: WazedKhan

LeetCode/medium/three_sum_closest_16.py

@@ -0,0 +1,20 @@
+from typing import List
+
+
+class Solution:
+    def threeSumClosest(self, nums: List[int], target: int) -> int:
+        nums.sort()
+        closest = nums[0] + nums[1] + nums[2]
+
+        for index in range(len(nums)):
+            left, right = index + 1, len(nums) - 1
+
+            while left < right:
+                three_sum = nums[index] + nums[left] + nums[right]
+                if three_sum < target:
+                    left += 1
+                else:
+                    right -= 1
+                if abs(three_sum - target) < abs(closest - target):
+                    closest = three_sum
+        return closest

tests/test_leetcode_medium.py

@@ -155,6 +155,25 @@ def test_three_sum(nums, expected):
     assert normalized_result == normalized_expected
 
 
+@pytest.mark.parametrize(
+    "nums, target, expected",
+    [
+        ([-1, 2, 1, -4], 1, 2),
+        ([0, 0, 0], 1, 0),
+        ([0, 0, 0], 0, 0),
+        ([1, 1, 1, 0], -100, 2),
+        ([1, 1, -1, -1, 3], -1, -1),
+        ([-3, -2, -5, 3, -4], -1, -2),
+        ([4, 0, 5, -5, 3, 3, 0, -4, -5], -2, -2),
+    ],
+)
+def test_three_sum_closest(nums, target, expected):
+    from LeetCode.medium.three_sum_closest_16 import Solution
+
+    result = Solution().threeSumClosest(nums, target)
+    assert result == expected, f"expected: {expected} but got: {result}"
+
+
 # 05: Longest Palindromic Substring
 # https://leetcode.com/problems/longest-palindromic-substring/?envType=problem-list-v2&envId=hash-table