Implement Hash Map with in-place
Last updated: March 18, 2026
Quick Overview
Implement a hash map that supports in-place insertion, deletion, and retrieval of key-value pairs. The hash map should handle collisions using chaining or open addressing and must maintain an average time complexity of O(1) for these operations. Your implementation should also include methods to return the current size of the hash map and check if a key exists.
Supabase
March 18, 202640
13
3,865 solved
Implement a hash map that supports in-place insertion, deletion, and retrieval of key-value pairs. The hash map should handle collisions using chaining or open addressing and must maintain an average time complexity of O(1) for these operations. Your implementation should also include methods to return the current size of the hash map and check if a key exists.
Coding interviews at Supabase focus on problem-solving approach as much as the final solution. The interviewer wants to see you break down the problem, consider edge cases, and optimize iteratively. Communication throughout the process is key.
What the Interviewer Expects
- Quickly identify the optimal approach and its theoretical basis
- Handle complex algorithm design with multiple interacting components
- Write concise, elegant code under time pressure
- Prove correctness of your approach and discuss alternative solutions
- Optimize beyond the obvious: discuss constant factor improvements
- Address follow-up variations and explain how the solution generalizes
Key Topics to Cover
How to Approach This
- Clarify input constraints and edge cases before writing code.
- Walk through your approach verbally and confirm with the interviewer before coding.
- Start with a brute force solution, then optimize. Mention time and space complexity.
- Test your solution with examples, including edge cases like empty input or duplicates.
- Consider common patterns: sliding window, two pointers, hash map, BFS/DFS, dynamic programming.
Possible Follow-up Questions
- How would your solution change if the input was sorted?
- Can you solve this in a single pass?
- How would you modify your solution to handle streaming input?
- What if the input doesn't fit in memory?
Sharpen Your Skills on Codemia
Practice similar problems with our interactive workspace, get AI feedback, and track your progress.
Practice DSA ProblemsSample Answer
Problem Analysis
The problem requires us to implement a hash map that supports in-place insertion, deletion, and retrieval of key-value pairs with an average time complexity of O(1). To achieve this, we will use an ar...
Approach
- Initialization: Create a class
HashMapthat contains an array (let's say of size 10) and a count of current elements. - Hash Function: Implement a method to generate a hash index based o...
Submit Your Answer
