Medium

Quiz

#128 Longest Consecutive Sequence

APPROACH

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
1 of 4
1:00

What is the optimal approach for this problem?