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 751–780 of 1080 results
- OracleMediumSoftware EngineerDetect whether a directed graph given as an edge list contains a cycle
A coding question that asks whether a directed graph, given as a node count and a list of edges, contains at least one directed cycle. It tests graph traversal on large inputs and careful handling of self-loops, duplicate edges, converging paths and disconnected components.
Coding & AlgorithmsOnsite - OracleMediumSoftware EngineerEnumerate Right-and-Down Paths Through a Binary Matrix
This problem tests your ability to explore paths in a grid using depth-first search (DFS) with backtracking while maintaining lexicographical output constraints.
Coding & AlgorithmsOnsiteDFSBacktrackingRecursion - OracleMediumSoftware EngineerFewest Coins for an Amount with Unlimited or Single-Use Coins
Return the fewest coins that add up exactly to an amount, first when every coin value can be reused without limit and then when each listed coin can be used at most once. An onsite coding problem that tests the difference between unlimited and single-use selection and the handling of amounts that cannot be formed.
Coding & AlgorithmsOnsite - OracleMediumSoftware EngineerFind Each Island's Maximum Height
This problem tests your ability to perform graph traversal (BFS/DFS) on a 2D grid while maintaining state across connected components.
Coding & AlgorithmsOnsiteGraphBFSDFS - OracleMediumSoftware EngineerFind shortest subarray meeting target sum
Find shortest subarray meeting target sum 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 & AlgorithmsOnsite - OracleMediumBackend EngineerFind the Best Profit from One Stock Trade
Tests array traversal, greedy state tracking, and achieving optimal O(n) time and O(1) space complexity for trade optimization.
Coding & AlgorithmsOnsiteArrayDynamic ProgrammingGreedy - OracleMediumSoftware EngineerFind the Lexicographically Maximum Suffix
This problem tests string manipulation, greedy algorithm design, and efficiency. It requires an O(n) solution to avoid Time Limit Exceeded errors on long strings, as naive O(n^2) comparisons will fail.
Coding & AlgorithmsOnsiteStringsTwo PointersGreedy - OracleMediumSoftware EngineerFind users with at least one valid session
This question evaluates the ability to parse and process event logs, pair signin/signout events per user, and handle unordered timestamps and per-user state with time-window constraints.
Coding & AlgorithmsOnsite - OracleMediumSoftware EngineerLargest Island After Converting at Most One Water Cell to Land
Given a grid of land and water, convert at most one water cell to land and return the size of the largest island that can result. An onsite follow-up coding problem that tests connected-component sizing, joining neighboring islands without counting one twice, and efficiency on grids up to 500 by 500.
Coding & AlgorithmsOnsite - OracleMediumSoftware EngineerMaximize Movie Ratings Without Skipping Two in a Row
Find the maximum possible sum of a subsequence such that no two consecutive elements from the original array are omitted.
Coding & AlgorithmsOnsitedynamic-programmingarraysgreedy - OracleMediumSoftware EngineerMaximize Profit with One Stock Transaction
This problem tests the ability to find the optimal buy and sell points for a stock within a single transaction, focusing on an efficient O(n) single-pass approach.
Coding & AlgorithmsOnsiteArraysGreedyDynamic Programming - OracleMediumSoftware EngineerMerge Accounts by Shared Identifiers
This problem tests graph traversal techniques (BFS/DFS) and Disjoint Set Union (DSU) to group connected entities based on shared attributes.
Coding & AlgorithmsOnsiteGraphDSUDFS - OracleMediumSoftware EngineerMinimize sum with halving operations
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Minimize sum with halving operations states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite - OracleMediumSoftware EngineerMinimum number of rooms needed to hold overlapping meetings
A coding question that asks for the minimum number of rooms needed so that every meeting in an unsorted list of half-open time intervals can be held without overlap. It tests reasoning about overlapping intervals, the boundary rule for meetings that end and start at the same time, and an efficient solution for large inputs.
Coding & AlgorithmsOnsite - OracleEasySoftware EngineerProcess Tokens with Explicit Expiration Times
This problem tests your ability to manage temporal data using efficient data structures, specifically focusing on handling expiration logic and range-based queries.
Coding & AlgorithmsOnsiteHash MapHeapDesign - OracleMediumSoftware EngineerRemove Even-Positioned Nodes from a Linked List
This problem tests your ability to manipulate singly linked list pointers in-place, specifically managing alternating node removals while maintaining correct connectivity.
Coding & AlgorithmsOnsiteLinked ListPointersAlgorithms - OracleEasySoftware EngineerReplace a Range of Nodes in a Linked List with Another Linked List
Given two singly linked lists and two indices i and j, replace nodes i through j of the first list with every node of the second list and return the new head. It tests careful pointer relinking, head and tail edge cases, and an empty replacement list.
Coding & AlgorithmsOnsite - OracleMediumSoftware EngineerReturn a valid course completion order
This question evaluates understanding of graph algorithms and dependency resolution, specifically skills in cycle detection and producing valid orderings of tasks.
Coding & AlgorithmsOnsite - OracleMediumBackend EngineerReturn the K Most Frequent Values with a Larger-Value Tie-Break
This problem tests proficiency with hash maps for frequency counting and custom sorting logic using priority queues or sorting algorithms.
Coding & AlgorithmsOnsiteHash MapSortingPriority Queue - OracleMediumSoftware EngineerShortest Subarray Whose Distinct-Value Sum Reaches a Target
Find the length of the shortest contiguous subarray of positive integers whose sum reaches a target when each distinct value is counted only once. A coding-screen problem that tests reasoning about contiguous ranges, bookkeeping for repeated values, and correct handling of the case where no subarray qualifies.
Coding & AlgorithmsOnsite - OracleEasySoftware EngineerSimulate a Least Recently Used Cache
This problem tests your ability to maintain data access recency and perform cache evictions in O(1) time complexity using a combination of a hash map and a doubly linked list.
Coding & AlgorithmsOnsiteData StructuresHash MapLinked List - OracleMediumSoftware EngineerSolve Five Coding Problems
This set tests proficiency across five key algorithmic domains: graph theory, array manipulation, numerical properties, cache design, and tree traversal.
Coding & AlgorithmsOnsiteGraphsLRU CacheRecursion - OracleMediumSoftware EngineerSolve three DSA problems: trie, window, intervals
This multi-part question evaluates proficiency with core data structures and algorithms — specifically trie-based string indexing and autocomplete design, sliding-window/prefix-sum optimization for maximizing a one-shot decrypted range, and interval merging — within the Coding & Algorithms domain, emphasizing practical implementation, complexity analysis and edge-case handling. It is commonly asked in technical interviews to assess the ability to design efficient data structures and linear-time algorithms, reason about time/space trade-offs and ordering constraints, and demonstrate both conceptual understanding and practical application through clear complexity analysis.
Coding & AlgorithmsOnsite - OracleMediumBackend EngineerSplit a String into Exactly Three Palindromes
Tests string partitioning, palindrome verification, and algorithmic optimization using dynamic programming or two pointers.
Coding & AlgorithmsOnsiteStringDynamic ProgrammingTwo Pointers - OracleMediumSoftware EngineerTimestamped key-value store: return each key's value as of a query time
A coding question that processes set and get operations on a key-value store where each write carries a timestamp and each read asks for a key's value as of a given time. It tests per-key version history, finding the latest write at or before a query time, and handling many interleaved operations efficiently.
Coding & AlgorithmsOnsite - OscarMediumSoftware EngineerSolve Morse and Network Access Tasks
This question evaluates string encoding/decoding and combinatorial parsing skills (Morse code conversion and ambiguous decoding) alongside spatial search and filtering competencies for proximity-based access checks, testing algorithmic reasoning, pattern recognition, backtracking possibilities, distance computation, and data-structure use.
Coding & AlgorithmsOnsite - OtherMediumSoftware EngineerFilter Logs by an Ordered Severity Threshold
Filter structured logs by an ordered minimum severity, preserving threshold-and-higher records while handling empty and unknown levels under an explicit contract.
Coding & AlgorithmsOnsite - OtherMediumData ScientistImplement KNN from scratch
This question evaluates understanding of the k-Nearest Neighbors algorithm, distance metrics (Euclidean and cosine), tie-breaking with class priors, weighted voting, complexity analysis, and scalability strategies, testing competencies in algorithm implementation, model behavior, and computational trade-offs.
Coding & AlgorithmsOnsite - OtherMediumMachine Learning EngineerImplement Linear Regression Training
This question evaluates understanding of linear regression, mean squared error loss, gradient computation, parameter updates, and proficiency with vectorized numerical operations used in batch gradient descent.
Coding & AlgorithmsOnsite - OtherMediumData ScientistProve reservoir sampling correctness
This question evaluates randomized and streaming algorithm skills, including mastery of reservoir sampling, induction-based correctness proofs, probability reasoning, and complexity analysis for sampling under strict memory constraints.
Coding & AlgorithmsOnsite
Oracle