Representative Topological Sort problems
Determine if all courses can be completed by analyzing prerequisite dependencies using indegree tracking and topological sorting to detect cycles.
Open problem page#210 Course Schedule IISolve the 'Course Schedule II' problem using graph indegree and topological ordering, utilizing DFS or BFS to find the correct course order.
Open problem page#310 Minimum Height TreesIdentify all roots of a tree that produce minimum height using graph indegree analysis and topological trimming.
Open problem page#329 Longest Increasing Path in a MatrixFind the length of the longest increasing path in a matrix with given movement constraints using graph techniques.
Open problem page#802 Find Eventual Safe StatesSolve the problem of finding eventual safe states in a directed graph using depth-first search and topological sorting.
Open problem page#851 Loud and RichDetermine the quietest person richer than each individual using graph indegree analysis and topological ordering techniques.
Open problem page#913 Cat and MouseDetermine the outcome of a two-player Cat and Mouse game on a graph using topological ordering and memoized dynamic programming.
Open problem page#1203 Sort Items by Groups Respecting DependenciesSort items into groups while respecting dependencies using graph indegree tracking and topological ordering patterns effectively.
Open problem page#1462 Course Schedule IVDetermine if one course is a prerequisite of another using graph indegree tracking and topological ordering efficiently.
Open problem pageTopological Sort interview questions usually collapse into a small set of repeatable moves. This page groups those GhostInterview problem pages together so you can stay inside one pattern family, compare representative questions, and practice explanations that transfer across multiple prompts. If you are trying to sharpen one interview weakness instead of browsing the entire library, start here.
Why Topological Sort Matters In Coding Interviews
Interviewers rarely care about the label alone. They care about whether you can recognize when the Topological Sort pattern applies, explain why it applies, and avoid the failure modes that usually show up under time pressure. That is why this page focuses on the family of problems rather than a single isolated example.
Pattern families that show up here
- Graph indegree plus topological ordering
- Array scanning plus hash lookup
Use this page to narrow the session
Start from this topic hub, choose one or two representative problems, and then open the detailed problem pages only after you know which version of the pattern you want to reinforce.
How To Practice This Topic
The best workflow is to keep the prep block narrow. Pick one easy or medium problem to confirm the base pattern, then one medium or hard problem to test whether the explanation still holds when the constraints tighten. Once the logic is stable, move into GhostInterview to rehearse the live explanation flow.
Focus on transfer, not title count
Solving more Topological Sort titles is less useful than understanding how the same move changes across examples. Try to describe what stays the same and what changes from one problem to the next.
Use the problem page when you want the exact breakdown
This topic hub is the discovery layer. The single-problem pages are where you get the answer-first summary, examples, constraints, approach, complexity, pitfalls, and solver CTA.
How GhostInterview Fits
GhostInterview works best after you know which pattern family you are inside. Use this page to choose the right Topological Sort problem, then use the solver to get the answer path, complexity framing, and follow-up support without switching into a generic study flow.
FAQ
What does the Topological Sort topic usually test in interviews?
Topological Sort questions usually test whether you can spot the underlying pattern quickly, explain the trade-offs, and move from intuition to implementation without losing clarity.
How should I use this Topological Sort topic page?
Use it as a pattern hub. Start with the representative problems on this page, compare the common approach, and then open the exact problem page when you want the full breakdown.
How many GhostInterview problem pages are in the Topological Sort group?
This topic page currently groups 28 indexed GhostInterview problem pages under the Topological Sort family.
Should I practice this topic before harder patterns?
That depends on your current gaps. If Topological Sort is already a weak spot in interviews, it is usually better to stabilize it first before moving into more advanced or less frequent patterns.
Where does GhostInterview fit once I pick a Topological Sort problem?
The topic page narrows the pattern family. The problem page gives the exact breakdown. GhostInterview is the solver layer when you need direct help with execution, complexity, and follow-up handling.
Stay close to the same reasoning family
141 overlapping problems
Open topic pageArray1,672 overlapping problems
Open topic pageDepth-First Search252 overlapping problems
Open topic pageDynamic Programming529 overlapping problems
Open topic pageBreadth-First Search197 overlapping problems
Open topic pageMatrix221 overlapping problems
Open topic pageNeed direct help once you choose a Topological Sort problem?
Use GhostInterview as the solver layer after you select the exact prompt. Capture the question, get the answer path and complexity framing, and keep the workflow inside the same topic family.