feat: solve longest-consecutive-sequence

Author: pmjuu

longest-consecutive-sequence/pmjuu.py

@@ -0,0 +1,22 @@
+from typing import List
+
+class Solution:
+    def longestConsecutive(self, nums: List[int]) -> int:
+        # Convert to set for O(1) lookups
+        num_set = set(nums)
+        longest_length = 0
+
+        for num in num_set:
+            # Only start counting if num is the start of a sequence
+            if num - 1 not in num_set:
+                current_num = num
+                current_length = 1
+
+                # Count the length of the sequence
+                while current_num + 1 in num_set:
+                    current_num += 1
+                    current_length += 1
+
+                longest_length = max(longest_length, current_length)
+        
+        return longest_length