Representative Counting Sort problems
Determine a researcher's h-index by analyzing citations using array sorting and counting techniques efficiently and accurately.
Open problem page#561 Array PartitionMaximize the sum of minimums of n pairs in a 2n integer array using a greedy pairing strategy efficiently.
Open problem page#912 Sort an ArraySort an array using an optimal algorithm, focusing on time and space complexity considerations.
Open problem page#1051 Height CheckerDetermine how many students are out of place in a line by comparing their heights to the sorted expected order efficiently.
Open problem page#1122 Relative Sort ArraySort arr1 by the relative order of arr2, with remaining elements placed in ascending order.
Open problem page#1365 How Many Numbers Are Smaller Than the Current NumberIn this problem, you need to determine how many numbers are smaller than each element in an array, focusing on array scanning and hash lookup.
Open problem page#1833 Maximum Ice Cream BarsMaximize the number of ice cream bars a boy can buy by applying a greedy choice strategy based on cost sorting.
Open problem page#2037 Minimum Number of Moves to Seat EveryoneCalculate the minimum total moves to seat each student using greedy assignment and invariant validation efficiently.
Open problem page#3517 Smallest Palindromic Rearrangement IBuild the smallest palindrome by sorting the left half counts and mirroring them around the optional middle character.
Open problem pageCounting 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 Counting Sort Matters In Coding Interviews
Interviewers rarely care about the label alone. They care about whether you can recognize when the Counting 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
- Greedy choice plus invariant validation
- Array plus Sorting
- 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 Counting 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 Counting 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 Counting Sort topic usually test in interviews?
Counting 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 Counting 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 Counting Sort group?
This topic page currently groups 9 indexed GhostInterview problem pages under the Counting Sort family.
Should I practice this topic before harder patterns?
That depends on your current gaps. If Counting 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 Counting 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
Need direct help once you choose a Counting 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.
