Related Coding / DSA
Cheapest Route Within a Stop Limit
Given one-way routes between cities each with a cost, find the cheapest total cost from a source city to a destination city using at most k intermediate stops.
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
- 6Handwritten tests 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 naive BFS-per-query baseline and improve to union-find with path compression and union by rank/size.
- ✓Think aloud while implementing careful find/union logic.
- ✓Validate with explicit expected outputs and a top-to-bottom handwritten 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
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
Determine a Valid Course Completion Order
Given a number of courses and a list of prerequisite pairs, determine a valid order to complete all courses, or report that no valid order exists.
Related Coding / DSA
Fewest Moves to Solve a Sliding Tile Puzzle
Given a small 2-by-3 sliding tile puzzle board with one blank space, find the minimum number of adjacent tile slides needed to reach a specified target arrangement, or report it is unreachable.
Related Coding / DSA
Count Connected Land Regions in a Grid
Given a 2D grid of land and water cells, count the number of distinct connected land regions, where cells are connected horizontally or vertically.