Count kth largest element in linked list
Last updated: November 22, 2025
Quick Overview
Given a singly linked list, write a function to find and return the kth largest element in the list. The function should take the head of the linked list and an integer k as input, and output the kth largest value. If k is greater than the number of elements in the list, return null.
ServiceNow
November 22, 202528
11
2,461 solved
Given a singly linked list, write a function to find and return the kth largest element in the list. The function should take the head of the linked list and an integer k as input, and output the kth largest value. If k is greater than the number of elements in the list, return null.
Coding interviews at ServiceNow 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 if the input doesn't fit in memory?
- How would you parallelize this solution?
- What is the worst-case input for your solution?
- 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 find the kth largest element in a singly linked list, we can recognize that this problem involves sorting or maintaining a collection of elements in a specific order. The most suitable pattern here...
Approach
- Initialize a min-heap to keep track of the k largest elements from the linked list.
- Traverse the linked list node by node:
- For each node, add its value to the min-heap.
- If the size of ...
Submit Your Answer
