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Longest Consecutive Sequence
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# Longest Consecutive Sequence

Contributed by
Ashwani
Medium
0/80
Avg time to solve 40 mins
Success Rate 70 %
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## Problem Statement

#### Note:

``````If there are any duplicates in the given array we will count only one of them in the consecutive sequence.
``````
##### For example-
``````For the given 'ARR' [9,5,4,9,10,10,6].

Output = 3
The longest consecutive sequence is [4,5,6].
``````
``````Can you solve this in O(N) time and O(N) space complexity?
``````
Detailed explanation ( Input/output format, Notes, Constraints, Images )
##### Sample Input 1 :
``````1
5
33 20 34 30 35
``````
##### Sample Output 1 :
``````3
``````
##### Explanation to Sample Input 1 :
``````The longest consecutive sequence is [33, 34, 35].
``````
##### Sample Input 2 :
``````1
7
1 9 3 10 4 20 2
``````
##### Sample Output 2 :
``````4
``````
##### Explanation to Sample Input 2 :
``````The consecutive sequence is in the form ['NUM', 'NUM' + 1, 'NUM' + 2,...,'NUM' + 'L']. So in the given array, the longest consecutive sequence is [1,2,3,4] where 'NUM' = 1 and 'L' = 3. And the length of the sequence will be 'L' + 1 = 4.
``````
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