Representative Data Stream problems
Implement a MedianFinder class that supports adding numbers and finding the median from a data stream.
Open problem page#703 Kth Largest Element in a StreamFind the kth largest element in a dynamic stream using binary-tree traversal and efficient state tracking with a min-heap.
Open problem page#901 Online Stock SpanDesign an efficient algorithm using stacks to calculate the stock span for daily price quotes.
Open problem page#933 Number of Recent CallsThe "Number of Recent Calls" problem involves designing a class to efficiently track recent requests within a time window.
Open problem page#1032 Stream of CharactersImplement a StreamChecker that detects if any suffix of a character stream matches a given list of words using efficient design.
Open problem page#1352 Product of the Last K NumbersDesign a data structure to efficiently return the product of the last k numbers in a dynamic integer stream using prefix products.
Open problem page#1472 Design Browser HistoryImplement a browser history tracker with back, forward, and visit operations using linked-list pointer manipulation efficiently.
Open problem page#1656 Design an Ordered StreamDesign an Ordered Stream that returns values in increasing order based on unique integer IDs with efficient insertion and retrieval.
Open problem page#1670 Design Front Middle Back QueueImplement a queue that efficiently handles push and pop operations at the front, middle, and back using pointer manipulation.
Open problem pageData Stream 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 Data Stream Matters In Coding Interviews
Interviewers rarely care about the label alone. They care about whether you can recognize when the Data Stream 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
- Queue-driven state processing
- Linked-list pointer manipulation
- Array plus Math
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 Data Stream 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 Data Stream 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 Data Stream topic usually test in interviews?
Data Stream 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 Data Stream 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 Data Stream group?
This topic page currently groups 13 indexed GhostInterview problem pages under the Data Stream family.
Should I practice this topic before harder patterns?
That depends on your current gaps. If Data Stream 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 Data Stream 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 Data Stream 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.