Related Coding / DSA
Reverse a Segment of a Linked List
Given the head of a singly linked list and two positions m and n, reverse the nodes from position m to position n in place and return the new head.
1. Problem Statement
You are given a number of servers labeled 0 to n-1. Implement connect(a, b) to record a direct connection, and isConnected(a, b) to report whether two servers are in the same connected group. Both operations will be called many times, interleaved.
2. Live Coding Format
Work in the provided coding workspace while explaining your decisions to the live interviewer. Validation may use inline tests, examples, comments, or a verbal walkthrough.
3. Key Focus Areas
- 1Problem clarification and contract
- 2Approach exploration and optimality
- 3Think-aloud communication and pacing
- 4Implementation correctness
- 5Code quality and language fluency
- 6Tests and dry run
- 7Debugging and self-correction
- 8Complexity analysis
- 9Follow-up performance
4. What Strong Candidates Should Demonstrate
- Clarify indexing, self-connections, and repeated-connection behavior before coding.
- Explain a search-per-query baseline and improve it so each connection and query takes nearly constant time.
- Think aloud while implementing readable, correct code.
- Validate with explicit expected outputs and a top-to-bottom dry run.
- Analyze time and space complexity and handle a bounded follow-up modification.
Want interactive feedback?
Practice this problem in the live coding workspace while the interviewer probes your clarification, implementation, trade-offs, and validation.
Continue to DashboardCore Concepts
Hidden because they name the technique, which a real interviewer would not tell you.
Show core concepts
Union-FindDisjoint Set UnionGraphsComplexity Analysis
Continue preparing
Build a complete software engineer mock interview plan
Prepare by company
Use this scenario in a focused preparation plan
Related Coding / DSA
Search in a Rotated Sorted Array
Given an array of distinct integers that was originally sorted ascending and then rotated at an unknown pivot, determine the index of a target value or report that it is absent.
Related Coding / DSA
Count Contiguous Runs Summing to a Target
Given a sequence of integers (possibly negative) and a target sum, count how many contiguous subarrays sum exactly to the target.
Related Coding / DSA
Maximize Sum with No Adjacent Elements
Given a list of integers, find the maximum sum you can obtain by choosing elements such that no two chosen elements are adjacent in the list. You may choose no elements, so the answer is 0 for an empty list or when every choice would reduce the sum.