Longest Consecutive Sequence

Given an unsorted array of integers nums, find the length of the longest sequence of consecutive elements.

Constraints

• n ≤ 100,000 where n is the length of nums

https://binarysearch.com/problems/Longest-Consecutive-Sequence

Examples

Example 1

Input

• nums = [100, 4, 200, 1, 3, 2, 101, 105, 103, 102, 104]

Output

• answer = 6

Explanation

The longest sequence of consecutive elements is [100, 101, 102, 103, 104, 105]. so we return its length: 6.

Example 2

Input

• nums = [100, 4, 200, 1, 3, 2]

Output

• answer = 4

Explanation

The longest sequence of consecutive elements is [1, 2, 3, 4]. so we return its length: 4.

Solution