Optimize rotation for O(1) space
Last updated: December 12, 2025
Quick Overview
Given an array of integers, rotate the array to the right by a specified number of steps, ensuring that the solution operates in O(1) space. The input consists of the array and the number of steps to rotate, and the output should be the modified array after rotation.
Confluent
December 12, 20250
13
2,766 solved
Given an array of integers, rotate the array to the right by a specified number of steps, ensuring that the solution operates in O(1) space. The input consists of the array and the number of steps to rotate, and the output should be the modified array after rotation.
Confluent uses this problem in the Technical Screen to evaluate your algorithmic thinking. They expect you to discuss multiple approaches, analyze trade-offs between them, and implement the optimal solution with clean, readable code.
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 happens if the input contains duplicates?
- How would your solution change if the input was sorted?
- How would you parallelize this solution?
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 rotate an array to the right by a specified number of steps while using O(1) space. This implies that we cannot use additional data structures like another array to store in...
Approach
- Normalize the number of steps: Since rotating an array of length n by n steps results in the same array, we can use
k = k % nto find the effective number of rotations. - **Reverse the entir...
Submit Your Answer
