Representative Array problems
Two Sum is solved fastest by storing seen values in a hash map and checking each number's needed complement once.
Open problem page#4 Median of Two Sorted ArraysFind the median of two sorted arrays using binary search for efficient O(log(min(m, n))) time complexity.
Open problem page#11 Container With Most WaterFind two vertical lines that can form a container with the most water in a given array of heights.
Open problem page#14 Longest Common PrefixFind the longest common prefix in an array of strings, returning an empty string if none exists.
Open problem page#15 3SumGiven an integer array, return all unique triplets where the sum is zero using two-pointer scanning with careful duplicate handling.
Open problem page#16 3Sum ClosestFind the sum of three integers in an array that is closest to a given target using two-pointer scanning.
Open problem page#18 4SumThe 4Sum problem requires finding all unique quadruplets in an array that sum to a specific target value.
Open problem page#26 Remove Duplicates from Sorted ArrayLearn how to remove duplicates from a sorted array in-place using two-pointer scanning while preserving element order.
Open problem page#27 Remove ElementRemove Element challenges you to remove a value from an array in-place using efficient two-pointer scanning and tracking.
Open problem pageArray 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 Array Matters In Coding Interviews
Interviewers rarely care about the label alone. They care about whether you can recognize when the Array 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
- Array scanning plus hash lookup
- State transition dynamic programming
- Binary search over the valid answer space
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 Array 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 Array 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 Array topic usually test in interviews?
Array 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 Array 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 Array group?
This topic page currently groups 1,672 indexed GhostInterview problem pages under the Array family.
Should I practice this topic before harder patterns?
That depends on your current gaps. If Array 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 Array 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 Array 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.