Optimize rotation for O(n) time
Last updated: September 19, 2025
Quick Overview
Given an array of integers representing the elements of a circular array, optimize the rotation of the array such that the operation completes in O(n) time. Your task is to implement a function that takes the array and a rotation count as input, and returns the rotated array as output. Ensure that your solution does not use additional space beyond a constant amount.
Supabase
September 19, 202524
12
742 solved
Given an array of integers representing the elements of a circular array, optimize the rotation of the array such that the operation completes in O(n) time. Your task is to implement a function that takes the array and a rotation count as input, and returns the rotated array as output. Ensure that your solution does not use additional space beyond a constant amount.
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
- Recognize the underlying problem pattern (sliding window, two pointers, BFS/DFS, etc.)
- Discuss multiple approaches and trade-offs before coding
- Implement an optimal solution with clean, production-quality code
- Handle all edge cases including boundary conditions and invalid input
- Optimize both time and space complexity with clear justification
- Test your solution systematically with well-chosen examples
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
- What is the worst-case input for your solution?
- How would you test this solution thoroughly?
- Can you solve this iteratively instead of recursively (or vice versa)?
- How would your solution change if the input was sorted?
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
In this problem, we are given a circular array and need to rotate it by a specified number of positions. The key pattern that applies here is the concept of modular arithmetic, which allows us to effi...
Approach
- Normalize the Rotation Count: If the rotation count
kis greater than the length of the arrayn, we can reduce it by calculatingk = k % n. This ensures we only perform necessary rotation...
Submit Your Answer
