wip: 3 pointers 3sum

medium/3sum.py

@@ -0,0 +1,33 @@
+#!/usr/bin/python
+# yigid balaban <fyb@fybx.dev>
+# neetcode                      2024
+# 3sum
+
+def solution(nums: list[int]) -> list[list[int]]:
+    if len(nums) < 3:
+        return []
+    if len(nums) == 3 and sum(nums) == 0:
+        return [nums]
+
+    nums = sorted(nums)
+    triples = []
+    def comb(what: list[int], head: int):
+        mtriples = []
+        for p0 in range(0, len(what) + 1):
+            for p1 in range(p0, len(what)):
+                if p1 != p0 and head + what[p0] + what[p1] == 0:
+                    triple = sorted([head, what[p0], what[p1]])
+                    if triple not in triples and triple not in mtriples:
+                        mtriples.append(triple)
+        return mtriples
+    
+    for p in range(len(nums) - 3):
+        triples.extend(comb(nums[p + 1:], nums[p]))
+    return triples
+
+print(solution([0,0]) == [])
+print(solution([-1,0,1,2,-1,-4]), solution([-1,0,1,2,-1,-4]) == [[-1,-1,2],[-1,0,1]])
+print(solution([0,1,1]) == [])
+print(solution([0,0,0]) == [[0,0,0]])
+print(solution([0,0,0,0]) == [[0,0,0]])
+