algoslayer's blog

By algoslayer, 10 months ago, In English

Hey everyone

I recently participated in Meta Hacker Cup 2025 Round 1 and I’m thrilled to share that I secured Rank 333 / 13,676 with a perfect score of 105/105, successfully solving every problem from A1 → D!

I've qualified for Round 2 of the Meta Hacker Cup 2025! Round 1 was a fantastic set of problems, and I managed to solve all of them for a full score.

This post includes my hints, solution approaches, and final codes for all problems — written to help learners strengthen their DSA and problem-solving intuition.

A1: Snakes Scales (Chapter 1) :

Hint
Solution
Code

A2: Snakes Scales (Chapter 2) :

Hint
Solution
Code

B1: Final Product (Chapter 1) :

Hint
Solution
Code

B2: Final Product (Chapter 2) :

Hint
Solution
Code

C: Narrowing Down :

Hint
Solution
Code

D: Crash Course :

Hint
Solution
Code

Final Thoughts

This round was an amazing experience—every problem had something new to learn:

  • Snakes Scales (A1, A2): A great ramp-up from simple iteration to a classic Binary Search + BFS/DFS.
  • Final Product (B1, B2): A fun test of mathematical insight, scaling from a simple construction to complex Number Theory and Combinatorics.
  • Narrowing Down (C): A clever $$$O(N)$$$ solution requiring a key insight with prefix XORs and a tricky counting formula.
  • Crash Course (D): A very deceptive game theory problem with a non-obvious optimal strategy.

I’ll soon be posting about Round 2 as well—stay tuned!

If you found this helpful, feel free to leave feedback or share your approaches below in the comments Contact me at LinkedIn or Github

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