Coding & Algorithms interview questions

Showing 751–780 of 3276 results

• Design a token manager with lazy expirationMedium

  This problem tests your ability to design a token management system that supports efficient retrieval, updates, and lazy removal of expired tokens using a combination of a hash map and a priority queue.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Design dynamic weighted random sampling with updatesMedium

  This question evaluates a candidate's ability to design and analyze dynamic data structures that support weighted random sampling with inserts and deletes, testing skills in algorithm design, complexity analysis, and randomized sampling under large numeric constraints.

  CitadelSoftware EngineerCoding & AlgorithmsOnsite
• Every MEX Reachable With At Most One Bounded IncrementHard

  A coding problem about memory blocks with values below n: using at most one increment of a single value, never raising a value to n, list every minimum excluded value (MEX) the array can end up with. It tests careful case analysis of how one increment can open or fill a gap, handling duplicate values, and returning the sorted answer efficiently.

  CitadelSoftware EngineerCoding & AlgorithmsOnline Assessment
• Every Reachable Priority Gap After At Most One Bounded BumpHard

  Given n network ports each tagged with a priority code below n, find every value the lowest unused priority code could take after at most one bounded increment. Tests careful case analysis of how a single bump opens or closes a gap, and returning the answer efficiently.

  CitadelSoftware EngineerCoding & AlgorithmsOnline Assessment
• Find earliest common meeting slotMedium

  This question evaluates proficiency with interval manipulation, timeline merging, and algorithmic reasoning for scheduling constraints, measuring competency in handling sorted interval lists, edge-case sanitization, and complexity analysis.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Find the Index Range of a Target in a Sorted ArrayMedium

  Implement an algorithm to find the first and last index of a target value in a sorted array in O(log n) time.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Find the Shortest Target-Sum PathMedium

  This problem tests your ability to navigate binary trees using recursion or iterative traversal while maintaining state to find a path that meets a specific sum criteria with the smallest number of nodes.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• First Free Locker Number After One Tag BumpHard

  Given locker tags in [0, n-1], list every possible smallest missing tag after at most one capped +1 adjustment. Tests MEX reasoning, careful case analysis around duplicates, and an O(n) solution.

  CitadelSoftware EngineerCoding & AlgorithmsOnline Assessment
• Generate Prefix-Based Product SuggestionsMedium

  Generate up to three lexicographically smallest product suggestions for every prefix of a search word, with efficient handling once a prefix has no matches.

  CitadelSoftware EngineerCoding & AlgorithmsOnsite
• Implement Infinite Fibonacci Generator Using Lazy EvaluationMedium

  This question evaluates understanding of lazy evaluation and Python generator semantics, testing a candidate's ability to work with iterative sequence production and manage state across iterations.

  CitadelData ScientistCoding & AlgorithmsTechnical Screen
• Implement LRU/LFU cache with custom evictionEasy

  This problem tests your ability to design a generic cache structure that supports interchangeable eviction strategies, requiring efficient lookup and metadata management.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Implement Piecewise Linear Interpolation and ExtrapolationMedium

  Implement piecewise linear interpolation from unsorted knots, including exact-knot behavior and endpoint extrapolation. Practice paired sorting, binary search, and numerical edge cases.

  CitadelData ScientistCoding & AlgorithmsTechnical Screen
• Implement a single-producer multi-consumer ring bufferMedium

  This question evaluates understanding of ring-buffer data structures, circular indexing, fixed-capacity storage, and object-oriented design for a single-producer, multi-consumer implementation in C++.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Implement an in-memory order book APIEasy

  This problem tests your ability to design an in-memory data structure for an order book using efficient data structures to support order management and price-level aggregation.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Implement array merge, round-robin scheduler, and trading simulatorMedium

  This problem tests your ability to manipulate data structures efficiently, implement a fair process scheduler, and manage event-driven state transitions.

  CitadelSoftware EngineerCoding & AlgorithmsOnsite
• Implement lazy unique-merge generator for sorted streamsMedium

  This question evaluates knowledge of lazy evaluation, Python generators/iterators, merging nondecreasing streams with duplicate elimination, and considerations of time and space complexity in streaming contexts.

  CitadelData ScientistCoding & AlgorithmsTechnical Screen
• Implement task queue with insert, delete, executeMedium

  This question evaluates a candidate's ability to design and implement efficient dynamic priority management, including priority ordering, insertion-order tie-breaking, and support for add, remove, and execute operations.

  CitadelSoftware EngineerCoding & AlgorithmsOnsite
• Implement two-pointer unique-pair sum searchMedium

  Implement two-pointer unique-pair sum search evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  CitadelData ScientistCoding & AlgorithmsTechnical Screen
• Match a string with wildcard pattern recursivelyMedium

  This problem tests your ability to implement a recursive pattern-matching algorithm that handles specific wildcard characters while managing overlapping subproblems.

  CitadelData ScientistCoding & AlgorithmsTechnical Screen
• Maximize Earnings by Adding Working DaysMedium

  Maximize schedule earnings by changing at most k days off into working days, balancing fixed daily pay with bonuses for consecutive working days.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Maximize Earnings by Converting Days OffMedium

  Tests dynamic programming and state tracking to maximize daily earnings and consecutive work streak bonuses under a budget of schedule changes.

  CitadelSoftware EngineerCoding & AlgorithmsHR Screen
• Merge K Drone Telemetry Streams Into a Running Altitude TimelineMedium

  Interleave K drones' individually time-ordered altitude logs into a single replay and track the fleet's shared altitude total as each logged change is applied. Tests k-way merging with a heap, a deterministic tie-break across drones, and correct handling of negative deltas and drones with no events.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Merge K Timestamp-Sorted Price Feeds into a Running Absolute PriceMedium

  Merge K price-event feeds, each already sorted by timestamp, into one chronological stream and return the running absolute price after every event, starting from zero. It tests merging sorted sequences efficiently, a deterministic tie-break for equal timestamps by feed index and then in-feed order, negative deltas, empty feeds, and 64-bit accumulation.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Merge K timestamped lists with timestamp coalescingMedium

  This problem tests your ability to efficiently merge multiple sorted streams of data and aggregate values associated with the same timestamp.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Minimize Changes to Make Every Password Block PalindromicMedium

  Tests string manipulation and two-pointer techniques to determine the minimum character replacements needed to make independent fixed-length blocks palindromic.

  CitadelSoftware EngineerCoding & AlgorithmsHR Screen
• Minimize changes for k-periodic palindromeMedium

  This question evaluates understanding of string algorithms and combinatorial reasoning, focusing on palindrome properties combined with k-periodicity and the ability to minimize character changes under global constraints.

  CitadelSoftware EngineerCoding & AlgorithmsOnline Assessment
• Minimize image processing cost with discountMedium

  This question evaluates a candidate's competence in algorithm design and optimization, including interval-based cost aggregation and modular arithmetic for large-number results within the Coding & Algorithms domain.

  CitadelSoftware EngineerCoding & AlgorithmsOnline Assessment
• Perform an External Merge Sort with a HeapMedium

  Implement an external merge sort simulation that partitions a data stream into memory-bounded sorted runs and merges them using a min-heap.

  CitadelSoftware EngineerCoding & AlgorithmsOnsite
• Read and Write Files with Shared ContentEasy

  Design an in-memory file system that shares identical content payloads across multiple file paths to save memory, supporting reads, writes, and deduplication tracking.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen
• Return a Valid Dependency Order for Named TasksMedium

  Implement a deterministic topological sort for a directed acyclic graph of named tasks with cycle detection and lexicographical tie-breaking.

  CitadelSoftware EngineerCoding & AlgorithmsTechnical Screen