Count Matrix Cells Whose Row and Column Neighbors Match
Last updated: July 2, 2026
Quick Overview
This question asks the candidate to write a function that counts the number of cells in a matrix where the values of the neighboring cells in the same row and column match the value of the cell itself.
Hudson River Trading
July 2, 202615
0
166 solved
This question asks the candidate to write a function that counts the number of cells in a matrix where the values of the neighboring cells in the same row and column match the value of the cell itself.
This question is typically asked during the technical screen round to evaluate a candidate's problem-solving and coding skills, particularly in handling matrix data structures. The interviewer is looking for the candidate's ability to implement an efficient algorithm, handle edge cases, and write clean, maintainable code.
What the Interviewer Expects
- Understand the problem requirements and constraints.
- Propose an efficient algorithm to traverse the matrix.
- Implement the solution with clear and concise code.
- Discuss the time and space complexity of the solution.
- Handle edge cases, such as empty matrices or matrices with only one cell.
Key Topics to Cover
How to Approach This
- Apply SOLID principles. Single Responsibility makes code testable, Open/Closed makes it extensible.
- Choose data structures based on access patterns, not familiarity.
- Prefer immutable data and message passing over shared mutable state for concurrency.
- Design APIs with RESTful conventions, versioning, meaningful errors, and pagination from day one.
Possible Follow-up Questions
- How would you optimize your solution further?
- Can you explain the time complexity of your approach?
- What would you do if the matrix could contain negative numbers?
Sharpen Your Skills on Codemia
Practice similar problems with our interactive workspace, get AI feedback, and track your progress.
Practice System Design ProblemsSample Answer
Requirements
The task requires counting the number of cells in a given matrix where the values of the neighboring cells in the same row and column match the value of the cell itself. Neighbors are defined as the c...
High-Level Design
To solve this problem, we will iterate through each cell in the matrix and check its four neighbors: left, right, above, and below. For each cell, we will compare its value with the values of its neig...
Submit Your Answer
