- Solution for "Longest Consecutive Sequence #240".

Author: ayosecu

longest-consecutive-sequence/ayosecu.py

@@ -0,0 +1,33 @@
+from typing import List
+
+class Solution:
+    """
+        - Time Complexity: O(n), n = len(set_nums) = The number of unique numbers.
+        - Space Complexity: O(n)
+    """
+    def longestConsecutive(self, nums: List[int]) -> int:
+        set_nums = set(nums)
+        longest = 0
+
+        for num in set_nums:
+            if num - 1 not in set_nums:
+                # Only check for the start number
+                cnt = 1
+                next_num = num + 1
+                while next_num in set_nums:
+                    cnt += 1
+                    next_num += 1
+                longest = max(longest, cnt)
+        
+        return longest
+
+tc = [
+        ([100,4,200,1,3,2], 4),
+        ([0,3,7,2,5,8,4,6,0,1], 9),
+        ([1,0,1,2], 3)
+]
+
+for i, (nums, e) in enumerate(tc, 1):
+    sol = Solution()
+    result = sol.longestConsecutive(nums)
+    print(f"TC {i} is Passed!" if result == e else f"TC {i} is Failed!, Expected: {e}, Result: {result}")