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• 0128. Longest Consecutive Sequence
  • Approach
  • Python
  • C++

TODO 0128. Longest Consecutive Sequence   medium

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.

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

Constraints:

• 0 <= nums.length <= 10^{5}
• -10^{9} <= nums[i] <= 10^{9}

TODO Approach

Write your approach here.

TODO Python

class Solution:
    def longestConsecutive(self, nums: List[int]) -> int:

TODO C++

class Solution {
public:
    int longestConsecutive(vector<int>& nums) {
        
    }
};