Transform linked list to adjacency list
Last updated: November 11, 2025
Quick Overview
Given a linked list where each node contains a value and a reference to its adjacent nodes, transform this linked list into an adjacency list representation. The output should be a list of lists, where each inner list contains the values of the nodes that are directly connected to the corresponding node in the original linked list. Ensure that the solution efficiently handles cases with varying node connections and is optimized for performance.
SpaceX
November 11, 20255
13
4,231 solved
Given a linked list where each node contains a value and a reference to its adjacent nodes, transform this linked list into an adjacency list representation. The output should be a list of lists, where each inner list contains the values of the nodes that are directly connected to the corresponding node in the original linked list. Ensure that the solution efficiently handles cases with varying node connections and is optimized for performance.
Coding interviews at SpaceX 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?
- What if the input doesn't fit in memory?
- Can you solve this iteratively instead of recursively (or vice versa)?
- What is the worst-case input for your 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 transforming a linked list into an adjacency list representation. Each node in the linked list has a value and references to its adjacent nodes. The adjacency list is a standard r...
Approach
- Initialize an empty list
adjacency_listto store the connections. - Create a mapping from the node's reference to its index in the adjacency list for quick access.
- Iterate through the lin...
Submit Your Answer
