Solving Longest Consecutive Sequence in Javascript. Please try yourself first to solve the problem and submit your implementation to LeetCode before looking into solution.

Problem Description

Given an unsorted array of integers, find the length of the longest consecutive elements sequence. Your algorithm should run in O(n) complexity.

Example

Input: [100, 4, 200, 1, 3, 2]
Output: 4

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

See the full details of the problem Longest Consecutive Sequence at LeetCode

Originally posted at: @github.com/ignacio-chiazzo/Algorithms-Leetcode-Javascript