Create longest-consecutive-sequence.py

leetCode/array/longest-consecutive-sequence.py

@@ -0,0 +1,48 @@
+# https://leetcode.com/problems/longest-consecutive-sequence/
+class Solution:
+    def longestConsecutive(self, nums: List[int]) -> int:
+        if len(nums) == 0:
+            return 0
+
+        numbers = set() 
+        min_num = min(nums)
+        max_num = max(nums)
+
+        for x in nums:
+            numbers.add(x)
+
+        while len(nums) > 1 and (min_num + 1) not in numbers:
+            numbers.discard(min_num)
+            if len(numbers) == 0:
+                return 1
+            min_num = min(numbers)
+
+        while len(nums) > 1 and (max_num - 1) not in numbers:
+            numbers.discard(max_num)
+            if len(numbers) == 0:
+                return 1
+            max_num = max(numbers)
+
+        last = min_num
+        count = 1
+        max_count = 1
+
+        # print(f"min_num: {min_num}, max_num: {max_num}")
+        for x in range(min_num + 1, max_num + 1):
+            # print(f"x: {x}, numbers[x]: {numbers[x]}, count: {count}, max_count: {max_count}")
+            if x in numbers:
+                if x == last + 1:
+                    count += 1
+                else:
+                    count = 1
+
+                last = x
+            elif count > max_count:
+                max_count = count
+                count = 0
+
+        if count > max_count:
+            max_count = count
+            count = 0
+
+        return max_count