practice a little every day, paws crossed ♡
Coding & Algorithms Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 871–900 of 3276 results
- DRWEasySoftware EngineerFewest Expenses to Defer to Year End So the Running Balance Never Goes Negative
Given a year's transactions in order, with income as positive values, expenses as negative values and a non-negative total, find the fewest expenses to move to the end of the year so the running balance never drops below zero. It tests reasoning over prefix sums for inputs of up to 100,000 transactions.
Coding & AlgorithmsTechnical Screen - DRWEasyData EngineerImplement Nested Transactions in an In-Memory Database
This problem tests your ability to manage state and scope using stacks and dictionaries to implement transaction isolation in a key-value store.
Coding & AlgorithmsOnline AssessmentHash MapStackTransactions - DRWMediumSoftware EngineerLargest Number From a 1-and-2 Digit String With Even Counts of Each Digit
Given a string of 1s and 2s that represents a positive integer, delete characters so the remaining counts of both digits are even, keeping the original order, and return the largest number that can remain. The problem tests careful case analysis of which digit occurrences to remove and efficient string handling for inputs up to 200,000 characters.
Coding & AlgorithmsHR Screen - DRWEasySoftware EngineerLongest Substring in Which Every Present Letter Occurs Equally Often
Given a string of lowercase letters, find the length of the longest substring in which every letter that appears occurs the same number of times. It tests substring enumeration with incremental frequency tracking and a precise definition of what counts as balanced.
Coding & AlgorithmsTechnical Screen - DRWHardSoftware EngineerMaximize a Digit Subsequence with Even Counts of Ones and Twos
Find the lexicographically/numerically largest subsequence of a string of '1's and '2's containing an even number of both digits in linear time.
Coding & AlgorithmsHR Screengreedystringssubsequences - DRWEasySoftware EngineerMinimize the Max-Min Gap of an Array After Changing Up to Three Elements
Given an integer array, you may change up to three elements to any values; return the smallest possible difference between the largest and smallest values afterward. It tests reasoning about which extreme values are worth changing and careful handling of short arrays.
Coding & AlgorithmsTechnical Screen - DRWMediumData ScientistSolve movie ratings, array, release scheduler
This question tests algorithmic problem-solving across three domains: greedy array optimization, tree-based data structure design, and efficient sequence merging. It evaluates practical coding ability and complexity analysis, commonly used in quantitative and data science interviews to assess how candidates identify inefficiencies and select the right data structure to improve performance.
Coding & AlgorithmsOnsite - DRWMediumSoftware EngineerSolve odd-string, digit swap, patient slot assignment
This multi-part problem evaluates string manipulation and parity/combinatorics for constructing odd-occurrence strings, greedy optimization and minimal-change reasoning for digit-swap distance minimization, and bipartite matching/assignment skills for patient slot allocation.
Coding & AlgorithmsOnline Assessment - DRWMediumSoftware EngineerSolve three algorithmic OA problems
This set evaluates algorithmic problem-solving skills including array manipulation and simulation for knockout tournament dynamics, graph traversal and constructive movement-sequence design on grids, and broader competencies in handling permutations, connectivity, and constraint-driven constructions.
Coding & AlgorithmsOnline Assessment - DRWMediumSoftware EngineerSolve three algorithmic OA tasks
Solve three algorithmic OA tasks 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.
Coding & AlgorithmsOnline Assessment - DRWMediumData ScientistSolve three algorithmic tasks in Python
This question evaluates proficiency in dynamic programming, range-query data structures (Fenwick/segment tree), sorting and two-pointer techniques, and algorithmic complexity analysis within the Coding & Algorithms domain for Python-based implementation.
Coding & AlgorithmsOnsite - DRWEasyData EngineerValidate a Password Against Explicit Security Rules
This problem tests string manipulation, character set validation, and the ability to apply a sequence of conditional checks efficiently.
Coding & AlgorithmsOnline AssessmentStringsValidationIteration - Dark Alpha CapitalMediumSoftware EngineerMinimize Total Assignment Distance
This question evaluates competency in combinatorial optimization, assignment/matching problems, and reasoning about Manhattan distance cost metrics. Commonly asked to assess algorithmic reasoning about constrained assignments, search and complexity trade-offs, it belongs to the Coding & Algorithms domain and emphasizes practical application of algorithm design and implementation rather than purely conceptual theory.
Coding & AlgorithmsTechnical Screen - DatabricksHardSoftware EngineerBuild a Constant-Time Snapshot Set Iterator
Design a mutable ordered integer set that supports constant-time snapshot iterator creation without copying the live dataset, preserving insertion order and handling elements that are removed and re-added.
Coding & AlgorithmsOnsiteData StructuresDesignLinked List - DatabricksMediumSoftware EngineerCheck if CIDR is fully canceled by rules
This question evaluates understanding of IPv4 CIDR arithmetic, set operations on IP ranges (overlap detection and subtraction), and ordered rule semantics for allow/deny processing.
Coding & AlgorithmsTechnical Screen - DatabricksMediumSoftware EngineerChoose fastest transportation mode on city grid
This problem tests your ability to model a grid-based transportation network as a graph and apply Dijkstra's algorithm to find the optimal path under multiple constraints.
Coding & AlgorithmsTechnical ScreenGraphsDijkstraShortest Path - DatabricksMediumSoftware EngineerCompute 5-minute rolling average load
This problem tests your ability to maintain a rolling window average over a high-throughput stream of events using an efficient data structure that balances memory usage and query time complexity.
Coding & AlgorithmsTechnical ScreenSliding WindowData StructuresTime Series - DatabricksMediumSoftware EngineerCompute last-5-minute QPS in memory
This question evaluates design of in-memory data structures and sliding-window time-series aggregation for real-time metrics, testing understanding of space/time trade-offs, streaming algorithms, and handling monotonic timestamps.
Coding & AlgorithmsTechnical Screen - DatabricksHardSoftware EngineerConvert an IP range to minimal CIDRs
This problem tests your ability to manipulate IP address representations and implement a greedy strategy to decompose an arbitrary range of IPv4 addresses into the minimum number of CIDR blocks.
Coding & AlgorithmsOnsiteBit ManipulationGreedyNetworking - DatabricksMediumMachine Learning EngineerDelete a Character From Cover
This problem tests your ability to manage dynamic string indices by maintaining a set of active intervals and adjusting them efficiently after a character deletion.
Coding & AlgorithmsOnsiteStringsIntervalsArrays - DatabricksMediumSoftware EngineerDesign BFS to detect forced win in Tic-Tac-Toe
This question evaluates algorithm design and search-space reasoning, focusing on BFS-based game-tree exploration, state representation, symmetry reduction and hashing, win/draw detection, pruning and move-ordering heuristics, and time/space complexity analysis in terms of n, k, t, and the branching factor within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - DatabricksMediumSoftware EngineerDesign IP/CIDR rule matcher
This question evaluates understanding of IPv4 addressing, CIDR and numeric range representations, plus competency in designing efficient data structures and algorithms for low-latency rule matching with dynamic updates.
Coding & AlgorithmsTechnical Screen - DatabricksMediumMachine Learning EngineerDesign In-Memory QPS Counter
This question evaluates the ability to design and implement an in-memory time-series counter and sliding-window aggregation, emphasizing efficient data structures, handling high-frequency events, and memory-time trade-offs.
Coding & AlgorithmsTechnical Screen - DatabricksMediumSoftware EngineerDesign Tic-Tac-Toe and QPS data structures
This question evaluates data-structure and API design skills, covering state management and efficient update/query algorithms for a generalized Tic-Tac-Toe with uniform-random move selection, as well as time-series aggregation and streaming-log techniques for computing QPS from non-decreasing timestamps.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerDesign a rolling event tracker with ranges
This question evaluates understanding of time-series data structures and streaming counters, testing algorithm design, space/time complexity analysis, correctness across edge cases, and handling of large-scale event tracking.
Coding & AlgorithmsTechnical Screen - DatabricksMediumSoftware EngineerDesign an IP filter using CIDR rules
This question evaluates understanding of IP addressing and CIDR notation, bit-level conversion between prefixes and integer ranges, and the design of scalable data structures and algorithms for prefix/range queries, rule priority handling, and rule-set operations (allow/deny semantics).
Coding & AlgorithmsTechnical Screen - DatabricksMediumSoftware EngineerDesign an efficient Tic-Tac-Toe engine
This question evaluates a candidate's understanding of efficient algorithm design and minimal state management for a Tic-Tac-Toe engine on an n x n board, including constraints such as O(1) time per move and O(n) space.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerDesign an n x n Tic-Tac-Toe Game
This problem tests your ability to design an efficient class to manage game state, focusing on constant-time win condition checking using auxiliary data structures.
Coding & AlgorithmsOnsiteObject-Oriented DesignData StructuresOptimization - DatabricksMediumSoftware EngineerDetect a K-in-a-Row Win on a Rectangular Board
Implement an efficient win-detection function that checks whether a newly placed token forms at least k consecutive matching tokens along any linear axis on a rectangular grid.
Coding & AlgorithmsOnsiteArraysMatrixGame Theory - DatabricksHardSoftware EngineerDetermine allow/deny for an IP via CIDR rules
This problem tests your ability to efficiently manage and query hierarchical IP address ranges, requiring knowledge of bitwise operations and data structures for range matching.
Coding & AlgorithmsTechnical ScreenBit ManipulationTrieNetworking
DRW
Databricks