3sum solution

mrlee7 · mrlee7 · commit 4652c720479d · 2026-03-15T23:40:30.000+09:00
diff --git a/3sum/mrlee7.py b/3sum/mrlee7.py
@@ -0,0 +1,34 @@
+from typing import List
+
+
+class Solution:
+    def threeSum(self, nums: List[int]) -> List[List[int]]:
+        result: List[List[int]] = []
+        nums.sort()
+
+        for i in range(len(nums) - 2):
+            if i > 0 and nums[i] == nums[i - 1]:
+                continue
+
+            left = i + 1
+            right = len(nums) - 1
+
+            while left < right:
+                total = nums[i] + nums[left] + nums[right]
+
+                if total == 0:
+                    result.append([nums[i], nums[left], nums[right]])
+                    left += 1
+                    right -= 1
+
+                    while left < right and nums[left] == nums[left - 1]:
+                        left += 1
+                    while left < right and nums[right] == nums[right + 1]:
+                        right -= 1
+
+                elif total < 0:
+                    left += 1
+                else:
+                    right -= 1
+
+        return result
