Merge overlapping collinear segments in the planeCodingSegments in 2D each carry an ordered list of points. Merge segments that lie on the same line and overlap, keeping every point, and take care with vertical segments and…
Last asked Oct 2026
#intervals
Is the store open? Hours with split shifts and overnight windowsCodingWrite a check that answers whether a store is open at a given moment, in Java. The schedule starts simple and gets richer step by step, and every earlier query must keep working…Last asked Oct 2026
+4Maximum overlap of closed intervalsCodingGiven a list of closed intervals start, end (both endpoints included), return the largest number of intervals that contain one point on the number line. Two intervals that only…Last asked Sep 2026
+1GPU credit ledger with out-of-order eventsCodingBuild an in-memory ledger for GPU credits. Credit arrives as grants: each one has a unique id, an amount, and a time window in which it can be spent. Grants may overlap in time…Last asked Sep 2026
Deployment windows in a recurring weekCodingDeployments are planned on a recurring week measured in minutes, from 0 to 10,079, and the same schedule repeats every week. Teams declare windows in which deployment is allowed…Last asked Sep 2026- Memory allocator: leftmost free block and free by ownerCodingA memory has n units, numbered 0 to n - 1, all free at the start. Process a list of operations in order, each producing one recorded value: 1. Allocate size units for an owner:…Last asked Sep 2026
+1Weighted job schedulingCodingEach job has a start time, an end time and a profit. Choose jobs that do not overlap to make the most profit. Sort jobs by end time; for each job, binary search for the last job…Last asked Sep 2026- Maximum coins from k consecutive bagsCodingBags stand at every positive integer position. Each segment l, r, v says every bag from l to r holds v; segments don't overlap and all other bags are empty. Choose k consecutive…Last asked Sep 2026
Ordered IP firewall with CIDR rulesCodingImplement an IPv4 firewall that checks addresses against an ordered list of rules. Each rule is a pair (action, target). action is "ALLOW" or "DENY". target is either a single…Last asked Sep 2026
Is a number line fully covered after each landing point?CodingPoints land one at a time on the segment 0, 50. Each point covers the interval of length 1 centred on it (0.5 to each side), and covered parts stay covered. After each landing…Last asked Sep 2026
Minimum buses to run a timetableCodingA bus depot has a timetable of trips, each with a departure time and an arrival time. A bus can take a new trip once it has arrived from its previous one. Return the fewest buses…Last asked Sep 2026- Fewest global replacements to group equal valuesCodingYou are given an integer array arr of length n. In one operation you pick two different values x and y that both currently appear in arr, and you change every occurrence of x into…Last asked Aug 2026
- +1Meeting 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 2026
+2Merge two sorted interval listsCodingImplement mergetwointervallists(a, b). Each argument is a list of intervals start, end with integer endpoints and start <= end. Each list is sorted by start, and no two intervals…Last asked Aug 2026
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 2026- Fewest rental cars for a set of reservationsCodingEach rental reservation has a start time and an end time. Find the fewest cars that can serve every reservation, and assign each reservation to a car. Follow-ups from other…Last asked Aug 2026
- Remove one point from a cover of integer intervalsCodingYou are given a list of non-overlapping half-open intervals. An interval start, end with start < end covers the integers start, start + 1, ..., end - 1. Reading the intervals in…Last asked Aug 2026
- +5Merge intervalsCodingGiven a list of intervals (for example time ranges), merge every group of overlapping intervals and return the result in sorted order.Last asked Aug 2026
- Check a new interval against existing ones for conflictsCodingGiven a set of existing intervals, decide whether a new interval overlaps any of them. Then discuss answering many such checks quickly as intervals keep being added, for example…Last asked Aug 2026
- Meeting rooms: attend all, rooms needed, busiest roomCodingGiven meetings as start and end times: 1. Can one person attend every meeting? 2. What is the fewest rooms needed to hold all of them? 3. With a fixed number of rooms and a rule…Last asked Aug 2026
- Time ranges with exactly X concurrent meetingsCodingGiven a list of meeting intervals and a number X, return the time ranges during which exactly X meetings are going on at once.Last asked Aug 2026
- Range moduleCodingTrack half-open integer ranges left, right): add a range, remove a range, and ask whether every number in a range is currently tracked.Last asked Jul 2026
- Shard rebalancing with a per-key replica limitCodingOur key-value store spreads keys across shards. Each shard is given as a string "<id:<start:<end" and owns every integer key in the inclusive range start, end. Shards may overlap…Last asked Jun 2026
- +1Days when the whole team is freeCodingA team is planning an offsite over a window of numdays days, numbered from 1 to numdays. Each team member has entered busy blocks as triples (personid, startday, endday). Both…Last asked Jun 2026
- Find conflicting eventsCodingGiven a list of events with start and end times, find the events that overlap one another.Last asked Jun 2026
- +1Employee shift timeline tableCodingEach shift is given as name, start, end, with integer times and start <= end. A shift covers the half-open interval start, end). One employee may have several shifts, and they may…Last asked Jun 2026
- Which interval contains a number?CodingBuild a class with addNonOverlappingInterval(start, end) and a query that says whether a number falls inside a stored interval (and which one). Discuss three versions: a linear…Last asked Jun 2026
Interval list intersectionsCodingGiven two lists of closed intervals, each sorted and non-overlapping within itself, return every intersection between an interval of the first list and one of the second.Last asked May 2026- Consolidate on-call rotation segmentsCodingAn on-call schedule is a list of segments, each naming a person and a start and end time. Merge the segments that belong to the same person and touch or overlap, and return the…Last asked May 2026
- Palindrome number and merge intervalsCodingTwo short problems: 1. Decide whether an integer reads the same forwards and backwards. 2. Merge a list of possibly overlapping ranges into the fewest non-overlapping ranges.Last asked Mar 2026
- Add bold tags around matching substringsCodingGiven a string and a list of words, wrap every part of the string that matches any word in bold tags. Overlapping or touching matches share one pair of tags. Mark the covered…Last asked Mar 2026
Courier pay from order eventsCodingA delivery courier is paid for active time. You receive the events of their orders (for example accepted and delivered, with timestamps) as if from an upstream service. Compute…Last asked Mar 2026- Busiest meeting room after simulated bookingsCodingSimulate booking meetings into a fixed set of rooms and return the room that held the most meetings. Agree on the rules first: which free room a meeting takes, and what happens to…Last asked Mar 2026
- Split stays across two listingsCodingA vacation rental site wants to offer split stays: when no single home is free for a guest's whole trip, the guest stays in one home first and then moves to another. There are n…Last asked Feb 2026
- +1Grep with context linesCodingImplement a simplified grep. You get a list of text lines, a search string target, and a non-negative integer k. Return every line that contains target, together with up to k…Last asked Feb 2026
- Minimum servers for daily jobs that wrap past midnightCodingEach job runs every day over a time window on a 24-hour clock, and a window may wrap past midnight (start later than end). A server runs one job at a time. Return the fewest…Last asked Feb 2026
- Meeting rooms: find conflicts and the minimum rooms neededCodingYou get room requests as half-open intervals start, end). First decide whether a single room can serve all of them (no two overlap). If not, return the fewest rooms needed so…Last asked Feb 2026
+1Meeting rooms IICodingGiven meeting start and end times, return the fewest rooms needed so no two overlapping meetings share a room, with a min-heap of end times or by sweeping sorted starts and ends.Last asked Feb 2026- Total listener time per live audio room from an event logCodingA time-ordered log records rooms being created and users joining and leaving them. Compute the total user-time spent in each room, handling users who never leave and rooms that…Last asked Feb 2026
- Free 30-minute time slotsCodingGiven the busy intervals in a day, return every available 30-minute slot.Last asked Jan 2026
- Meeting rooms with delayed starts: the busiest roomCodingThere are n rooms numbered from 0 and a list of meetings with distinct start times. Each meeting takes the free room with the lowest number; if none is free, it waits for the…Last asked Jan 2026
Find all GPU idle timesCodingFrom GPU task schedules, compute every idle window where no task runs. Reported on 1point3acres' Fireworks AI bank; reconstructed in our own words.Last asked Jan 2026
Party hours and quiet gaps by neighborhood and cityCodingA community events app records every party in two separate lists that share a partyId: - partyWindows: rows of partyId, start, end. start and end are hours as strings, and a party…Last asked Dec 2025- The skyline problemCodingBuildings are given as left, right, height rectangles on flat ground. Return the outline of the skyline they form, as the list of key points where the height changes. Use a sweep…Last asked Dec 2025
- Parking lot occupancy peaks from entry and exit eventsCodingYou get parking events carid, time, 'entry' 'exit', not necessarily in order. 1. What is the largest number of cars that were in the lot at the same time? 2. Return the time…Last asked Dec 2025
- +2Count intervals covering a pointCodingBuild a data structure over a fixed list of closed intervals on the integer number line that answers many point queries quickly. An interval l, r covers a point x when l <= x <=…Last asked Nov 2025
My calendar: book without double bookingCodingBuild a calendar whose book(start, end) accepts a half-open interval only if it does not overlap any existing booking. Compare a list scan with a sorted structure and binary…Last asked Nov 2025- Safe ranges between planets' gravity zonesCodingPlanets sit on a line; each is given as (center, radius) and makes the range within its radius unsafe. Return the safe ranges between the unsafe zones, in order. Turn each planet…Last asked Nov 2025
Print timed text intervals in order and flag overlaps and gapsCodingYou get a list of time intervals, each with a piece of text, and print them in time order, much like merge intervals. The follow-up asks you to report where two intervals overlap…Last asked Nov 2025- Employee free timeCodingYou get each employee's busy schedule as a sorted list of non-overlapping intervals. Return the finite intervals in which every employee is free, in sorted order. Merge the busy…Last asked Nov 2025
- Find the gaps between intervalsCodingGiven a list of intervals in any order, return every gap that no interval covers between the earliest start and the latest end. It is merge intervals, but you return the spaces in…Last asked Nov 2025
- Missing rangesCodingGiven a sorted list of distinct integers inside a fixed range (for example 0 to 99), list the gaps. In the reported variant a gap of up to three numbers is written out number by…Last asked Sep 2025
- 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…Last asked Sep 2025
- Insert intervalCodingGiven a list of non-overlapping intervals sorted by start and a new interval, insert the new one and merge wherever it overlaps, returning a sorted list of non-overlapping…Last asked Sep 2025
- Car poolingCodingA vehicle with a given capacity drives in one direction. Each trip is passengers, start, end. Return whether all trips fit without ever exceeding capacity, by sorting pickup and…Last asked Aug 2025
- Fewest intervals to remove so one covers the restCodingGiven a list of intervals, remove as few as possible so that among the remaining intervals at least one covers all the others. Return how many you remove.Last asked Jul 2025
- Total covered time per session from overlapping clipsCodingA dataset lists driving-log clips with a set id, a run id, a start time and an end time. Clips within a set can overlap. For each set, compute the total time covered by its clips…Last asked Jul 2025
+1Minimum workers with first-free job assignmentCodingJobs arrive as (jobid, start, end) with half-open times start, end). Workers are numbered 0, 1, 2, ... Part 1. Process jobs by start time (ties by job id). Each job goes to the…- Merge intervals for streaming GPU tasksCodingMerge overlapping time intervals for GPU tasks arriving as a stream. Reported on 1point3acres' Fireworks AI bank; reconstructed in our own words.
- Gift delivery scheduler with limited agentsCodingYou are planning gift deliveries to employees in an office. The workday runs from hour 9 to hour 17. You get: - intervals, a list of start, end pairs with integer hours. Employee…
- Smallest free hub for a taskCodingYou run a fleet of n compute hubs, numbered 0 to n - 1, and need to place one new task on a single hub. You are given: - capacities: an integer list of length n. capacitiesi is…