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A2Z Sheet

85. Longest Consecutive Sequence in an Array

Medium
Step 3: Solve Problems on Arrays [Easy -> Medium -> Hard]›Medium

Longest Consecutive Sequence in an Array

MediumFunction: longestConsecutiveSequenceInAnArray()
ASCI Mission Breakdown • Simple as Hell
"Master Longest Consecutive Sequence in an Array: Take `nums` (number[]), execute an optimal medium strategy, and return number[] with clean edge-case handling."
Real-World Metaphor:

Think of Longest Consecutive Sequence in an Array as an everyday real-world challenge: you receive input data, inspect its elements in sequence without making unnecessary duplicate passes, and transform the collection to reach the exact target without wasting computer memory.

Interactive Visual WalkthroughARRAY-POINTERS
Step 1 / 3
Longest Consecutive Sequence in an Array State Pipeline
start
1
[0]
2
[1]
3
[2]
4
[3]
5
[4]
Memory Notepad / State Tracker
Status:Initialized
Mode:Scanning
Evaluating

1. Initialize State for Longest Consecutive Sequence in an Array

Load inputs and initialize algorithmic registers.

How to Think About This (Mental Model)

  1. Unpack the problem parameters (`nums` (number[])) and clarify what is given vs what must be returned.
  2. Identify the optimal data structure or pattern (e.g. pointers, hash map, or stack) to avoid redundant recalculations.
  3. Walk through state transitions, handle edge cases (empty collections, single items, negative numbers), and return the verified result.

### The Mission Welcome to **Longest Consecutive Sequence in an Array**! In this challenge, your goal is to write a high-performance, clean solution in your chosen programming language. You are given `nums` (number[]). Your job is to process this input using optimal logic and return number[]. ### How to Approach It - Read through the inputs carefully and look for patterns. - Think about what state you need to track as you examine each element. - Strive for optimal time complexity and keep your code readable and structured.

Examples

Example 1
Input: nums = [1,2,3,4,5]
Output: [1,2,3,4,5]

Constraints

  • 1 <= nums.length <= 10^5
  • -10^9 <= nums[i] <= 10^9
Topic Tags:
Solve Problems on Arrays [Easy -> Medium -> Hard]MediumlongestConsecutiveSequenceInAnArray
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