Longest Consecutive Sequence Problem

Longest Consecutive Sequence Problem — ExecCode Medium DSA Practice

Solve the Longest Consecutive Sequence problem on ExecCode. Free online medium DSA practice in Hashing. Write and run code in Java, C++, Python — no signup required to run.

Problem description

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.

Examples

Input nums = [100, 4, 200, 1, 3, 2, 5, 6]; Output 6. Input nums = [0, 3, 7, 2, 5, 8, 4, 6, 0, 1]; Output 9. Input nums = []; Output 0

Constraints

0 ≤ nums.length ≤ 10⁵ -10⁹ ≤ nums[i] ≤ 10⁹

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