#128

Longest Consecutive Sequence

specialist · 915 · lc medium +31 · verified · 47% accepted · 22,760 likes · top 32%

⚑ General Lookup / Deduplication ⚑ Disjoint Set Union

Description

Given an unsorted integer array nums, find the length of the longest sequence of consecutive integers it contains.

Your solution must run in O(n) time.

Example 1:

Input: nums = [100,4,200,1,3,2]

Output: 4

Explanation: The longest consecutive elements sequence is [1, 2, 3, 4]. Therefore its length is 4.

Example 2:

Input: nums = [0,3,7,2,5,8,4,6,0,1]

Output: 9

Example 3:

Input: nums = [1,0,1,2]

Output: 3

Code

1

2

3

class Solution:
    def longestConsecutive(self, nums: List[int]) -> int:

class Solution:
    def longestConsecutive(self, nums: List[int]) -> int: