Detect palindrome in array
Last updated: February 3, 2026
Quick Overview
Given an array of integers, write a function to detect and return all unique palindromic subarrays. A palindromic subarray is defined as a contiguous sequence of elements that reads the same forwards and backwards. The function should output a list of these palindromic subarrays.
Citadel
February 3, 202622
10
366 solved
Given an array of integers, write a function to detect and return all unique palindromic subarrays. A palindromic subarray is defined as a contiguous sequence of elements that reads the same forwards and backwards. The function should output a list of these palindromic subarrays.
This coding problem is frequently asked during Take-home Project at Citadel. The interviewer is testing your ability to translate a problem into clean, working code while discussing time and space complexity. Citadel expects candidates to write production-quality code, not just solve the puzzle.
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
- Can you optimize the space complexity of your solution?
- How would your solution change if the input was sorted?
- What happens if the input contains duplicates?
- Can you solve this iteratively instead of recursively (or vice versa)?
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
To detect all unique palindromic subarrays in an array of integers, we can utilize the expand around center technique, which is particularly effective for palindrome detection. This approach works...
Approach
-
Iterate through the array: For each index, we will consider it as a potential center of a palindrome.
-
Expand Around Center: For each index, we will expand in both directions (left and r...
Submit Your Answer
