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Meta Coding Interview

Meta's fast set: stacks and parentheses, top-K, prefix products, and sliding windows.

Islands
8
Lessons
72
Exercises
249
Complete codeDebugCode orderMultiple choiceTapTrace
  1. Island 1

    Valid Parentheses

    Decide whether every bracket in a string opens and closes in the right order.

    1. Decode the Problem3 exercises, 4 min
    2. Approach Check4 exercises, 4 min
    3. Build the Brute Force3 exercises, 5 min
    4. Find the Bottleneck2 exercises, 4 min
    5. Discover the Optimal Approach3 exercises, 4 min
    6. Assemble the Algorithm2 exercises, 5 min
    7. Read the Implementation3 exercises, 5 min
    8. Test and Analyze3 exercises, 4 min
    9. Boss BattleBoss8 exercises, 8 min
  2. Island 2

    Kth Missing Positive Number

    An increasing array skips some positive integers — find the kth one it skipped.

    1. Decode the Problem3 exercises, 4 min
    2. Approach Check4 exercises, 4 min
    3. Build the Brute Force3 exercises, 5 min
    4. Find the Bottleneck2 exercises, 4 min
    5. Discover the Optimal Approach3 exercises, 4 min
    6. Assemble the Algorithm2 exercises, 5 min
    7. Read the Implementation3 exercises, 5 min
    8. Test and Analyze4 exercises, 4 min
    9. Boss BattleBoss8 exercises, 8 min
  3. Island 3

    Max Consecutive Ones III

    Flip at most k zeros to ones — find the longest all-ones stretch you can create.

    1. Decode the Problem3 exercises, 4 min
    2. Approach Check4 exercises, 4 min
    3. Build the Brute Force3 exercises, 5 min
    4. Find the Bottleneck2 exercises, 4 min
    5. Discover the Optimal Approach3 exercises, 4 min
    6. Assemble the Algorithm2 exercises, 5 min
    7. Read the Implementation3 exercises, 5 min
    8. Test and Analyze3 exercises, 4 min
    9. Boss BattleBoss8 exercises, 8 min
  4. Island 4

    Remove Duplicates from Sorted List II

    Delete every value that appears more than once from a sorted linked list — keeping only true singletons.

    1. Decode the Problem3 exercises, 4 min
    2. Approach Check4 exercises, 4 min
    3. Build the Brute Force3 exercises, 5 min
    4. Find the Bottleneck2 exercises, 4 min
    5. Discover the Optimal Approach3 exercises, 4 min
    6. Assemble the Algorithm2 exercises, 5 min
    7. Read the Implementation3 exercises, 5 min
    8. Test and Analyze3 exercises, 4 min
    9. Boss BattleBoss8 exercises, 8 min
  5. Island 5

    Product of Array Except Self

    For each position, compute the product of every other element — without using division.

    1. Decode the Problem3 exercises, 4 min
    2. Approach Check4 exercises, 4 min
    3. Build the Brute Force3 exercises, 5 min
    4. Find the Bottleneck2 exercises, 4 min
    5. Discover the Optimal Approach3 exercises, 4 min
    6. Assemble the Algorithm2 exercises, 5 min
    7. Read the Implementation3 exercises, 5 min
    8. Test and Analyze3 exercises, 4 min
    9. Boss BattleBoss8 exercises, 8 min
  6. Island 6

    Top K Frequent Elements

    Return the k values that occur most often in an array.

    1. Decode the Problem3 exercises, 4 min
    2. Approach Check4 exercises, 4 min
    3. Build the Brute Force3 exercises, 5 min
    4. Find the Bottleneck2 exercises, 4 min
    5. Discover the Optimal Approach3 exercises, 4 min
    6. Assemble the Algorithm2 exercises, 5 min
    7. Read the Implementation3 exercises, 5 min
    8. Test and Analyze3 exercises, 4 min
    9. Boss BattleBoss8 exercises, 8 min
  7. Island 7

    Minimum Remove to Make Valid Parentheses

    Delete the fewest parentheses so every remaining one is matched — letters stay put.

    1. Decode the Problem3 exercises, 4 min
    2. Approach Check4 exercises, 4 min
    3. Build the Brute Force3 exercises, 5 min
    4. Find the Bottleneck2 exercises, 4 min
    5. Discover the Optimal Approach3 exercises, 4 min
    6. Assemble the Algorithm2 exercises, 5 min
    7. Read the Implementation3 exercises, 5 min
    8. Test and Analyze3 exercises, 4 min
    9. Boss BattleBoss8 exercises, 8 min
  8. Island 8

    4Sum

    Find every unique quadruplet that hits a target sum — no repeats, any order inside.

    1. Decode the Problem3 exercises, 4 min
    2. Approach Check4 exercises, 4 min
    3. Build the Brute Force3 exercises, 5 min
    4. Find the Bottleneck2 exercises, 4 min
    5. Discover the Optimal Approach3 exercises, 4 min
    6. Assemble the Algorithm2 exercises, 5 min
    7. Read the Implementation3 exercises, 5 min
    8. Test and Analyze3 exercises, 4 min
    9. Boss BattleBoss8 exercises, 8 min
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Meta Coding Interview is part of AlgoFox Pro

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