feat: 128. Longest Consecutive Sequence

Author: HodaeSsi

longest-consecutive-sequence/HodaeSsi.py

@@ -0,0 +1,38 @@
+from typing import List
+
+
+class Node:
+    def __init__(self, value):
+        self.value = value
+        self.parent = None
+        self.child = None
+
+class Solution:
+    def longestConsecutive(self, nums: List[int]) -> int:
+        answer = 0
+        dict = {}
+
+        for num in nums:
+            if dict.get(num) is None:
+                dict[num] = Node(num)
+                if dict.get(num + 1) is not None:
+                    dict[num + 1].child = dict[num]
+                    dict[num].parent = dict[num + 1]
+                
+                if dict.get(num - 1) is not None:
+                    dict[num].child = dict[num - 1]
+                    dict[num - 1].parent = dict[num]
+                
+        for key in dict.keys():
+            if dict[key].parent is None:
+                node = dict[key]
+                count = 1
+
+                while node.child is not None:
+                    count += 1
+                    node = node.child
+
+                answer = max(answer, count)
+
+        return answer
+