longest consecutive

Author: E-1on

longest-consecutive-sequence/Sung-Heon.py

@@ -0,0 +1,21 @@
+class Solution:
+    def longestConsecutive(self, nums: List[int]) -> int:
+        if not nums:
+            return 0
+
+        num_set = set(nums)
+        longest = 0
+
+        visited = set()
+
+        for num in num_set:
+            if num not in visited and num - 1 not in num_set:
+                current = num
+                current_streak = 0
+                while current in num_set:
+                    visited.add(current)
+                    current_streak += 1
+                    current += 1
+                longest = max(longest, current_streak)
+
+        return longest