Uber coding interview

Questions Uber asks in this round 41

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  Design a parking lotOO designModel a multi-floor parking lot with spot types for motorcycles, cars and trucks: park, unpark, find free spots, and charge by time.

  Last asked Oct 2026Were you asked this too?
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  Meeting room scheduler over a fixed set of roomsCodingImplement a MeetingScheduler for a fixed set of meeting rooms. Each room has a unique string ID. - MeetingScheduler(roomids: liststr) sets up the rooms. Room IDs are unique. -…

  Last asked Aug 2026Were you asked this too?
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  Build a quadtreeCodingA quadtree splits a 2D region into four quadrants, recursively: every node is either a leaf or has exactly four children. Build one yourself. One version builds it from a square…

  Last asked Jun 2026Were you asked this too?
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  Sliding-window request rate limiterCodingImplement a rate limiter that accepts at most limit requests in any window of ttl milliseconds. - allow(timestamp) is called once per incoming request. timestamp is in…

  Last asked Jun 2026Were you asked this too?
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  Word search in a straight lineCodingGiven an m x n grid of uppercase letters board and a string word, decide whether word appears in the grid along a straight line. A match starts at some cell and reads len(word)…

  Last asked May 2026Were you asked this too?
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  Number of islandsCodingGiven a binary matrix, return how many islands it has: groups of 1 cells connected up, down, left or right (diagonals don't connect).

  Last asked Sep 2026Were you asked this too?
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  Number of islands as land is addedCodingA grid starts as all water. Positions are turned into land one at a time; after each addition, return the current number of islands (land cells connected up, down, left or right)…

  Last asked Sep 2026Were you asked this too?
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  Squares of a sorted array, then the k smallest squaresCodingYou get an integer array sorted in non-decreasing order; it may hold negative numbers. 1. Return the squares of all its elements in sorted order, faster than sorting again (O(n)…

  Last asked Sep 2026Were you asked this too?
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  Group anagramsCodingGroup the words in a list that are anagrams of one another, keeping repeated words. Build the grouping key from letter counts instead of sorting each word.

  Last asked Jun 2026Were you asked this too?
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  Fix a bug in an unfamiliar repo with an AI assistantCodingYou get a small full-stack repository, a reported defect and an AI coding assistant in the browser. Reproduce the problem, find the root cause, fix it and show the fix works…

  Last asked May 2026Were you asked this too?
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  Longest subarray with absolute difference within a limitCodingGiven an integer array and a limit, return the length of the longest contiguous subarray in which any two elements differ by at most limit. The expected answer is O(n): a sliding…

  Last asked May 2026Were you asked this too?
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  Live top-k best-selling books leaderboardCodingA bookstore wants a live leaderboard of its best-selling books. Sales arrive one at a time, and the leaderboard can be read at any moment. Implement a BookSalesTracker class: -…

  Last asked May 2026Were you asked this too?
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  Best time to buy and sell stock: one trade, then twoCodingGiven a stock's daily prices, return the most profit you can make: 1. With one buy and one later sell. 2. With at most two non-overlapping trades.

  Last asked Feb 2026Were you asked this too?
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  Shortest increasing path to a target value in a gridCodingGiven an integer grid, answer repeated queries. Each query names a target value; return the values along a shortest path from the top-left cell to a cell holding that value, where…

  Last asked Sep 2026Were you asked this too?
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  In-memory file system with files and foldersCodingImplement an in-memory file system with path-based file and folder access, plus follow-ups on per-directory limits, duplicate names and identical contents. Covers the bank's vault…

  Last asked Aug 2026Were you asked this too?
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  K closest points to a query locationCodingGiven a list of 2D points and a query location, return the k points closest to it by Euclidean distance. Compare sorting, a size-k max-heap and quickselect, and say which you…

  Last asked Aug 2026Were you asked this too?
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  Meeting rooms II: fewest rooms for a set of meetingsCodingGiven meetings as start, end) intervals, find the fewest rooms needed so that no two overlapping meetings share a room, and assign each meeting to a room.

  Last asked Aug 2026Were you asked this too?
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  Serialize and deserialize an N-ary treeCodingDesign a string format for a rooted tree in which each node has any number of children in a fixed order. Implement serialize(root) and deserialize(data) so that decoding gives…

  Last asked Jul 2026Were you asked this too?
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  Shortest path in a grid with blocked cellsCodingGiven a grid in which some cells are blocked, return the length of the shortest path from a start cell to a target cell, moving up, down, left or right, or report that no path…

  Last asked Jun 2026Were you asked this too?
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  Social follow graph with point-in-time snapshotsCodingBuild an in-memory follow graph that can answer questions about its own past. Follows are directed: a following b says nothing about b following a. Implement a SocialNetwork…

  Last asked Jun 2026Were you asked this too?
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  Alien dictionaryCodingYou get a list of words sorted in the dictionary order of an unknown alphabet. Derive an order of the letters that is consistent with it, or report that none exists. Explain how…

  Last asked Jun 2026Were you asked this too?
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  LRU cacheCodingBuild a key-value cache with a fixed capacity that evicts the least recently used entry when it is full. get(key) returns the value or a miss, put(key, value) inserts or updates…

  Last asked Jun 2026Were you asked this too?
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  Customer revenue with referral credit and bottom-k queryCodingBuild an in-memory system that tracks how much revenue each customer brings in, including revenue from the customers they referred. Customers get integer ids starting at 0, in the…

  Last asked Apr 2026Were you asked this too?
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  Find a local minimum in an arrayCodingReturn the index of any element smaller than its neighbours (the ends compare with their one neighbour). A linear scan works; the follow-up is logarithmic time by binary searching…

  Last asked Apr 2026Were you asked this too?
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  Zero array after range-decrement queriesCodingYou get an array of non-negative integers and a list of queries l, r. Each query lets you subtract 1 from any chosen positions between l and r. Decide whether the array can be all…

  Last asked Apr 2026Were you asked this too?
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  Deduplicate concurrent downloads of the same URLCodingWrite a downloader that many threads call with URLs. Downloads of different URLs run in parallel. When several threads ask for the same URL at the same time, only one of them…

  Last asked Apr 2026Were you asked this too?
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  Largest all-ones square and rectangle in a binary matrixCodingGiven a grid of 0s and 1s, return the area of the largest square made only of 1s. Then extend your approach to the largest all-ones rectangle.

  Last asked Apr 2026Were you asked this too?
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  Temporal key-value store with point-in-time reads and restoreCodingBuild an in-memory key-value store that keeps every version of every key, so you can ask what a key held at any point in time. Implement the TemporalKVStore class: -…

  Last asked Mar 2026Were you asked this too?
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  Nearest exit from a mazeCodingGiven a grid maze of walls and open cells and your starting cell, return the fewest steps to the nearest exit, an open cell on the border other than the start, or -1 if there is…

  Last asked Feb 2026Were you asked this too?
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  Vertical order traversal of a binary treeCodingGive every node of a binary tree a column (root at 0, left child one less, right child one more) and a row. Return the node values column by column from left to right, top to…

  Last asked Feb 2026Were you asked this too?
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  Cart and pricing engine for a food delivery orderOO designIn a food delivery marketplace, an order's final price is more than the sum of its menu items: item customizations such as extra toppings and sizes change it, and so do other…

  Last asked Jan 2026Were you asked this too?
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  Smallest starting index that never leaves on the leftCodingEach cell of an array holds a move: a positive number moves you that many cells right, a negative one moves you left. Starting from some index you keep following the moves. Find…

  Last asked Dec 2025Were you asked this too?
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  Group dependent tasks into parallel levelsCodingYou run a build system. Each task has a unique, non-empty lowercase name. Some tasks depend on others: a dependency before, after means before must finish before after can start…

  Last asked Dec 2025Were you asked this too?
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  Place K pickup points to minimize total L1 distanceCodingGiven the coordinates of N people, choose K shuttle pickup locations so that the sum of each person's Manhattan (L1) distance to their nearest pickup is as small as possible…

  Last asked Dec 2025Were you asked this too?
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  Earliest common slot in two calendarsCodingGiven two people's calendars as lists of time intervals and a meeting length, return the earliest slot of that length that works for both, or nothing. Clarify whether the…

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  Run three methods in a fixed order across threadsCodingThree methods, first(), second() and third(), are called by three different threads in any order. Make sure they always run in that order, using locks, events or semaphores.

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  Random point in non-overlapping squaresCodingDefine a class for a square on the plane and return a uniformly random point inside it. Follow-up: given many non-overlapping squares, return a point that is uniformly random over…

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  Folder path from a node idCodingA file browser stores its folder hierarchy as three parallel arrays: - idListi is a unique folder id. - childreni lists the ids of the folders directly inside folder idListi. -…

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  Levels cleared from every starting pointCodingA game has n levels in a row. You are given two integer arrays of length n, layers and energy, and an integer K. A run that starts at level i begins with exactly K energy and…

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  Longest valid bracket substring with nesting ranksCodingGiven a string made only of the characters (, ), , , { and }, return the length of the longest contiguous substring that is valid. A string is valid when all of these hold: 1…

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  Which prefixes of 1..n appear as a contiguous blockCodingYou are given an array p of length n that is a permutation of the integers 1..n (each value appears exactly once). For every k from 1 to n, decide whether p has a contiguous…

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