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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 1021–1050 of 1080 results
- VercelEasySoftware EngineerGroup Tree Nodes into Layers from the Leaves Up to the Root
Given a rooted tree described as an undirected edge list, return its nodes in layers from the leaves up to the root, where each node sits one layer above its highest child and each layer is sorted. It tests rooting a tree from a graph, bottom-up ordering, and handling very deep, path-shaped trees.
Coding & AlgorithmsOnsite - VercelMediumSoftware EngineerSearch Recorded Metrics by Name, Tags, and Recency
Design an in-memory metric storage and querying system that allows recording time-series metrics with key-value tags and retrieving the most recent matches filtered by name and tags.
Coding & AlgorithmsOnsitedata-structureshash-tablesorting - VerkadaMediumSoftware EngineerFind user who can access every camera
This problem tests your ability to model hierarchical access control systems as a directed graph and determine reachability using graph traversal techniques like BFS or DFS.
Coding & AlgorithmsOnsiteGraphsBFS/DFSReachability - VerkadaMediumSoftware EngineerImplement LRU and LFU caches
This question evaluates understanding of cache eviction policies and data structure design, focusing on LRU and LFU semantics and the ability to support O(1) average-time get/put operations.
Coding & AlgorithmsOnsite - VerkadaMediumFrontend EngineerImplement a recency cache and min-coins DP
This problem tests your ability to combine a Least Recently Used (LRU) cache mechanism with a dynamic programming approach for optimization.
Coding & AlgorithmsOnsiteHash MapDoubly Linked ListDynamic Programming - Virtu FinancialHardQuantitative ResearcherMaximum Edges in a Triangle-Free Graph
Determine the maximum number of edges an undirected, simple graph on n vertices can have without containing any triangle (K3), and construct one such extremal graph.
Coding & AlgorithmsOnsitegraph-theorymathcombinatorics - VisaMediumSoftware EngineerDesign rotating warehouse simulator with closures
This question evaluates algorithmic skills in designing efficient dynamic data structures and performing event-driven simulation with mutable state, specifically managing cyclic capacity resets and permanent closures in the Coding & Algorithms domain.
Coding & AlgorithmsOnsite - VisaMediumSoftware EngineerFind the Index of a Target in a Sorted Array of Distinct Integers
Practice locating a target value in a strictly increasing array of distinct integers, returning its zero-based index or -1 when it is absent. The task checks logarithmic-time search over sorted data, precise loop boundaries, and correct handling of single-element arrays and values that fall between or outside the stored elements.
Coding & AlgorithmsOnsite - VisaMediumSoftware EngineerLongest Strictly Rising Four-Direction Walk in an Integer Grid
A grid coding problem: find the length of the longest walk of strictly increasing values in an integer matrix, moving only up, down, left or right. It tests modeling a grid as a graph, handling equal neighboring values correctly, and an efficient search over grids of up to 40,000 cells.
Coding & AlgorithmsOnsite - VisaMediumSoftware EngineerMaintain pair-sum counts under replacements
This question evaluates the ability to design dynamic data structures and perform algorithmic complexity analysis for maintaining pair-sum counts under element replacements, testing skills in efficient query/update handling and scalability.
Coding & AlgorithmsOnsite - VoleonHardSoftware EngineerImplement Kac ring with O(1) color and kstep
This question evaluates understanding of algorithmic state representation, modular arithmetic, and efficient update/query design by requiring a Kac ring implementation that supports constant-time k-step advancement and O(1) aggregate color reporting.
Coding & AlgorithmsOnsite - VoleonHardSoftware EngineerProcess exchange prints, volume checks, and client orders
This problem tests your ability to manage high-frequency time-series data using sliding windows and stateful order tracking to enforce trading constraints.
Coding & AlgorithmsOnsiteSliding WindowStream ProcessingTime-Series - Walmart LabsMediumData ScientistFind Index Pairs of Matching Elements in Arrays
This question evaluates the ability to work with sorted arrays, index mapping, duplicate handling, and reasoning about correctness and algorithmic complexity.
Coding & AlgorithmsOnsite - Walmart LabsEasyMachine Learning EngineerFind first non-repeating character
This problem tests your ability to use hash maps or frequency arrays to achieve optimal time complexity when processing character streams or strings.
Coding & AlgorithmsOnsiteStringsHash MapFrequency Array - Walmart LabsHardSoftware EngineerFind the Single Repeated Value Among n + 1 Integers Drawn from 1 to n
Given an array of n + 1 integers whose values all lie between 1 and n, return the one value that repeats, possibly several times. The challenge is solving it without modifying the array and with constant extra memory, which rules out sorting, hash sets and counting arrays.
Coding & AlgorithmsOnsite - Walmart LabsHardSoftware EngineerProduct of All Other Elements for Each Index Without Division
For each position of an integer array, compute the product of all the other elements in linear time and without using division. It tests careful handling of zeros, negative values and repeated values, and planning a single efficient pass when the obvious division shortcut is not allowed.
Coding & AlgorithmsOnsite - WaymoMediumSoftware Engineer2D Max Pooling That Also Returns the Coordinates of Each Window Maximum
Implement 2D max pooling with a k-by-k window and a stride, and for each window also return the row and column of its maximum, breaking ties by smallest row then column. Tests window indexing without padding, output sizing, and argmax bookkeeping.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerCan You Reach the Last Index?
This problem tests your ability to determine reachability in a sequence using greedy strategy or dynamic programming to optimize pathfinding.
Coding & AlgorithmsOnsiteArraysGreedyDynamic Programming - WaymoMediumSoftware EngineerCharacter at a Position in a Run-Length Encoded String Without Decoding
Given a run-length encoded string such as B1A2E3C1, return the character at each queried position of the decoded sequence without decoding it. Runs can be very long, so the task tests prefix sums over run lengths and fast lookup per query.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerCount Squares Formed by Intersections of Vertical and Horizontal Segments
Given vertical and horizontal line segments defined by start and end points, count the axis-aligned squares whose four corners are all segment intersection points. Tests intersection detection, square enumeration, and faster ways to find which segments cross each other.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerDoes a Seven-Segment LED Digit Display Read the Same Rotated 180 Degrees?
Decide whether a row of digits on a seven-segment LED display reads the same after the whole display is rotated by 180 degrees. Tests modeling each digit as lit segments, mapping segments under rotation, and comparing the reversed display.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerEnd-Picking Number Game: Can the First Player Win Under Optimal Play?
Two players alternately take a number from either end of a row and add it to their score; decide whether the first player can finish with at least as many points as the second under optimal play. Tests minimax reasoning and memoized game-state search.
Coding & AlgorithmsOnsite - WaymoMediumFrontend EngineerFilter Matching Subtrees from an N-Ary Tree
This problem tests tree traversal techniques, string matching, and the ability to handle iterative tree processing to avoid stack overflow in deep structures.
Coding & AlgorithmsOnsiteTreesN-ary TreeAlgorithms - WaymoHardSoftware EngineerFind Dictionary Words Represented by Repeated Letters
Match dictionary words to a repeated-letter string using ordered run characters and count inequalities, with explicit stretch, duplicate, and empty-string semantics.
Coding & AlgorithmsOnsite - WaymoHardSoftware EngineerFind a Repeating Vehicle Program Under Fuel and Memory Limits
Find any repeating vehicle program of at most ten commands with fuel and obstacles, using complete bounded search, terminating simulation, and explicit execution assumptions.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerFixed-Capacity Least-Recently-Used Cache Driven by Get and Put Operations
Design a fixed-capacity least-recently-used cache as an object-oriented exercise, driven here by a list of get and put operations whose read results you return. Tests O(1) lookup, recency updates on reads and writes, and correct eviction order.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerFormat Bytes as a Hex and ASCII Dump
This problem tests string manipulation, modular arithmetic, and careful handling of formatting constraints to produce a standardized hexadecimal memory dump.
Coding & AlgorithmsOnsiteStringsFormattingImplementation - WaymoHardMachine Learning EngineerGenerate Instructions for a Blind Maze Robot
This question evaluates a candidate's ability to design algorithmic strategies for state-space synchronization, graph traversal, and reasoning under partial observability in grid environments.
Coding & AlgorithmsOnsite - WaymoEasyData ScientistImplement nested template string substitution
This problem tests your ability to handle recursive data structures and string parsing by expanding nested placeholders within a template string while identifying potential circular dependencies.
Coding & AlgorithmsOnsiteRecursionString ProcessingMemoization - WaymoMediumSoftware EngineerIn-Place Rectangle Copy Within a 2D Array Using O(1) Extra Memory
Copy a rectangular block of a 2D array to another position in the same array, in place with O(1) extra memory, where the source and destination blocks may overlap. Tests choosing a safe copy direction so that no value is overwritten before it is read.
Coding & AlgorithmsOnsite
Vercel
Verkada
Virtu Financial
Visa
Voleon
Walmart Labs
Waymo