Representative Recursion problems
Add Two Numbers requires careful linked-list pointer manipulation to sum digits while handling carries efficiently in interview settings.
Open problem page#10 Regular Expression MatchingThe Regular Expression Matching problem involves checking if a string matches a pattern using '.' and '*'.
Open problem page#21 Merge Two Sorted ListsMerge two sorted linked lists by splicing nodes into one sorted list using linked-list pointer manipulation and recursion.
Open problem page#24 Swap Nodes in PairsLearn how to swap every adjacent linked-list pair by rewiring nodes safely without changing values or breaking the remaining chain.
Open problem page#25 Reverse Nodes in k-GroupReverse Nodes in k-Group challenges you to reverse segments of a linked list in groups of size k.
Open problem page#44 Wildcard MatchingImplement full wildcard pattern matching using '?' and '*' by applying state transition dynamic programming with careful handling of edge cases.
Open problem page#50 Pow(x, n)Calculate x to the power n efficiently using recursion and exponentiation, handling negative powers and large inputs safely.
Open problem page#60 Permutation SequenceFind the kth permutation sequence of a set of numbers using math and recursion to efficiently compute the result.
Open problem page#143 Reorder ListReorder List requires careful pointer manipulation in a singly linked list to interleave nodes from the ends without altering values.
Open problem pageRecursion 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 Recursion Matters In Coding Interviews
Interviewers rarely care about the label alone. They care about whether you can recognize when the Recursion 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
- Linked-list pointer manipulation
- Math plus Recursion
- State transition dynamic programming
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 Recursion 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 Recursion 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 Recursion topic usually test in interviews?
Recursion 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 Recursion 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 Recursion group?
This topic page currently groups 40 indexed GhostInterview problem pages under the Recursion family.
Should I practice this topic before harder patterns?
That depends on your current gaps. If Recursion 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 Recursion 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
Need direct help once you choose a Recursion 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.
