[W5]

3sum solution

Author: sun912

3sum/sun912.py

@@ -0,0 +1,25 @@
+"""
+    TC: O(n^2)
+    SC: O(1)
+"""
+
+class Solution:
+    def threeSum(self, nums: List[int]) -> List[List[int]]:
+        result = set()
+        nums.sort()
+
+        for i in range(len(nums)-2):
+            left,right = i+1, len(nums)-1
+            while left < right:
+                three_sum = nums[i]+nums[left]+nums[right]
+
+                if three_sum < 0:
+                    left += 1
+                elif three_sum > 0:
+                    right -= 1
+                else:
+                    result.add((nums[i], nums[left], nums[right]))
+                    left,right = left+1, right-1
+
+        return list(result)
+