D. J.:

- Added the leetcode problem and solution for 128 Longest Consecutive Sequence

Author: nobodyPerfecZ

README.md

@@ -15,6 +15,7 @@ This repository contains awesome LeetCode problems and solutions written in Pyth
 - [121 Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/description/)
 - [122 Best Time to Buy and Sell Stock II](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/description/)
 - [125 Valid Palindrome](https://leetcode.com/problems/valid-palindrome/description/)
+- [128 Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/description/)
 - [169 Majority Element](https://leetcode.com/problems/majority-element/description/)
 - [189 Rotate Array](https://leetcode.com/problems/rotate-array/description/)
 - [202 Happy Number](https://leetcode.com/problems/happy-number/description/)

awesome_python_leetcode/_128_longest_consecutive_sequence.py

@@ -0,0 +1,20 @@
+from typing import List
+
+
+class Solution:
+    def longestConsecutive(self, nums: List[int]) -> int:
+        """
+        Given an unsorted array of integers nums, return the length of the
+        longest consecutive elements sequence.
+
+        You must write an algorithm that runs in O(n) time.
+        """
+        nums = set(nums)
+        longest = 0
+        for n in nums:
+            if n - 1 not in nums:
+                length = 0
+                while (n + length) in nums:
+                    length += 1
+                longest = max(longest, length)
+        return longest

tests/test_128_longest_consecutive_sequence.py

@@ -0,0 +1,17 @@
+from typing import List
+import pytest
+
+from awesome_python_leetcode._128_longest_consecutive_sequence import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["nums", "expected"],
+    argvalues=[
+        ([100, 4, 200, 1, 3, 2], 4),
+        ([0, 3, 7, 2, 5, 8, 4, 6, 0, 1], 9),
+        ([1, 0, 1, 2], 3),
+    ],
+)
+def test_func(nums: List[int], expected: int):
+    longest_consecutive = Solution().longestConsecutive(nums)
+    assert longest_consecutive == expected