{leetcode}/problems/longest-consecutive-sequence/[LeetCode - Longest Consecutive Sequence^]
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.
link:{sourcedir}/_0128_LongestConsecutiveSequence.java[role=include]