← Back to all problems
Medium

Longest Consecutive Sequence

Updated Feb 24, 2026

Problem

Return length of the longest consecutive elements sequence.

Constraints

0 <= nums.length <= 10^5

Examples

Example 1

Input: {"nums": [100, 4, 200, 1, 3, 2]}
Output: 4

Function Signature

def longestConsecutive(self, nums: list[int]) -> int

How to Submit

Implement a Solution class with a longestConsecutive method.

Your method will be called with the input parameters and should return the answer.