Problems
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Total results3,698 problems
| Title | Level | Topics | Solved | Time limit | Memory limit | Judge |
|---|---|---|---|---|---|---|
| Nap TimePick exactly B of N intervals arranged in a circle, maximizing sum of chosen values where the first interval of each consecutive block scores zero. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Closed-Circuit SurveillanceGiven a convex polygon and a set of candidate exterior camera points with costs, find the minimum total cost of camera placements so every polygon edge is visible (strictly, not collinear) from at least one chosen camera, or report -1 if impossible. | Hard8 | GeometryGreedy+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Number PairingPair adjacent grid cells whose value difference is at most T to maximize total pairing weight, which requires a general weighted matching approach exploiting the grid's bipartite structure. | Hard8 | GraphDynamic programming+1 | No attempts yet | 2s | 128 MB | Judgeable |
| MazeGiven a tree-like maze grid, compute the expected number of steps for a random depth-first exploration (choosing unvisited branches uniformly, backtracking on dead ends) to travel from entrance to exit. | Hard8 | TreeDFS+2 | No attempts yet | 2s | 128 MB | Judgeable |
| Tile GameGiven colored numbered tiles, compute the maximum score obtainable by repeatedly removing groups of at least three tiles that form a same-color numeric run or a same-number all-different-color set. | Hard8 | Dynamic programmingCombinatorics+1 | No attempts yet | 1s | 512 MB | Judgeable |
| Bicycle RaceGiven N riders each with energy E and a race of D laps, find the minimum integer number of minutes to finish, rotating who leads to share energy costs optimally. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Minimum Power OperationsGiven P up to 20000, find the minimum number of multiply or divide operations using only two variables to reach x^P from x and 1. | Hard8 | BFSDynamic programming+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Cheap but SimilarGiven a mineral row, decide whether equipment covering 1-3 consecutive cells can be placed to mine at least 75% of the total, and construct a valid placement if so. | Hard8 | GreedyDynamic programming+1 | No attempts yet | 7s | 16 MB | Judgeable |
| Number of TreesCount the number of rooted ordered trees whose DFS-with-repeated-parent-writes traversal string equals a given string, modulo 1e9. | Hard8 | Dynamic programmingString+1 | No attempts yet | 2s | 128 MB | Judgeable |
| TicketsAssign seat blocks of length L to families to maximize profit, where exact preferred block gives 2, any other free block of L seats gives 1, and blocks can't overlap. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Programming Language LSimulate execution of a custom esoteric language with nested loops and conditional jumps to find the maximum number of printed line executions, capping at infinity beyond 1e9. | Hard8 | SimulationDynamic programming+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Six People in a CircleGiven N people and an acquaintance graph, count the number of distinct 6-cycles (arrangements around a circle up to rotation and reflection) modulo 9901. | Hard8 | GraphCombinatorics+2 | No attempts yet | 2s | 128 MB | Judgeable |
| Block StackingCount A by B height-grids with heights 0 to C that are non-increasing along both rows and columns, modulo 1e18. | Hard8 | Dynamic programmingCombinatorics+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Compressing a StringFind the minimum length of a string obtained by optimally applying nested k(S) run-length style compression to a given lowercase string of length up to 200. | Hard8 | Dynamic programmingString+1 | No attempts yet | 2s | 128 MB | Judgeable |
| MinesweeperGiven a Minesweeper board where only border cells are revealed with numbers, determine the maximum number of mines that can be placed in the closed interior cells consistently with the border clues. | Hard8 | Dynamic programmingCombinatorics+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Jumping FencesFind a closed walk from a start point visiting exactly K points that maximizes the product of fence-jumping success probabilities over all moves, given fences that block segments between points. | Hard8 | GraphDynamic programming+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Planning a TripGiven a directed graph, find the maximum number of distinct cities visitable on a walk from S to T, allowing revisits of cities and edges. | Hard8 | GraphDFS+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Two SequencesPartition two sequences from the back into matched groups to minimize the total sum of products of adjusted group sums, requiring an optimized DP over prefix sums. | Hard8 | Dynamic programmingPrefix sum+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Polynomial CalculatorFind the minimum number of key presses to build a given monic polynomial using a calculator that applies operations sequentially without memory. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Nuclear BombSelect a subset of given segments forming a convex polygon that encloses a fixed point, minimizing total cost, or report impossibility. | Hard8 | GeometryGraph+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Reducing Tree HeightGiven a weighted rooted tree, find the minimum total edge-weight reduction needed so every root-to-leaf distance is at most H. | Hard8 | TreeDynamic programming+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Safe CrackingGiven N dial values that can be cyclically increased and merged when adjacent and equal, find the minimum total seconds to make all dials equal, considering rotation direction and wraparound. | Hard8 | Dynamic programmingDivide and conquer+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Grid SeparatorGiven a grid graph with an initial minimal white/gray/black separator path, find the minimum size separator reachable by specific add/remove transformations. | Hard8 | GraphDynamic programming+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Building Profit PlanGiven points with profits, select a subset maximizing total profit such that every chosen point sees other chosen points only in diagonal quadrant pairs (1,3) or (2,4) relative to itself. | Hard8 | Dynamic programmingSorting+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Number of Expression ValuesCount the distinct values an unspaced digit/operator string can yield when each subexpression is parsed as prefix, infix, or postfix. | Hard8 | Dynamic programmingString+2 | No attempts yet | 2s | 128 MB | Judgeable |
| Wedding ProcessionArrange all guests in a line minimizing the sum of adjacent height differences while keeping the given lion subsequence order fixed. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Obstacle Course DesignCount the number of ways to arrange m distinct-height obstacles into a nested valid course whose ground-to-ground climbing difficulty equals exactly k. | Hard8 | Dynamic programmingCombinatorics+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Cutting the Stone SlabCount the number of ways to repeatedly cut an N x N stone slab with alternating horizontal/vertical straight cuts so every final piece has no impurity and exactly one crystal. | Hard8 | Dynamic programmingRecursion+2 | No attempts yet | 2s | 128 MB | Judgeable |
| Square-Substring-Free NumberGiven N up to 10^18, find the smallest number at least N whose decimal representation contains no perfect square as a substring. | Hard8 | Dynamic programmingString matching+1 | No attempts yet | 1s | 1024 MB | Judgeable |
| DriveFind a path from S to T in a weighted undirected graph minimizing extra cost incurred whenever an edge's weight falls outside the running min-max range of used edges. | Hard8 | Shortest pathGraph+2 | No attempts yet | 2s | 128 MB | Judgeable |
| Divisor Subsequence SeriesGiven N, repeatedly delete digits forming a proper divisor subsequence to build the longest possible chain, breaking ties lexicographically smallest. | Hard8 | BacktrackingGreedy+2 | No attempts yet | 2s | 128 MB | Judgeable |
| I'm a Frayed KnotGiven sequences of colored thread endpoints, count the orderings of adjacent ties that merge all threads into a single loop without prematurely closing a smaller cycle. | Hard8 | CombinatoricsDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Drive TourFind two vertex-disjoint (except endpoints) monotonic increasing and decreasing paths between city 1 and city N that together visit the maximum number of distinct cities, and output the combined route. | Hard8 | Dynamic programmingGraph+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Connecting PointsCount simple Hamiltonian polygons using all 3xN grid points with king-move adjacency, for N up to 1e9, mod 1e9. | Hard8 | CombinatoricsDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Student GroupsPartition an ordered list of students into contiguous groups minimizing mismatches between grouping and a given friendship graph, using DP over prefix structure with an efficient cost computation. | Hard8 | Dynamic programmingGraph+1 | No attempts yet | 1s | 256 MB | Judgeable |
| Easy Group MatchingGiven a text sequence and two patterns, count group-matching positions for each pattern, then find the smallest integer n that maximizes group matches for the concatenated pattern P1·n·P2 and report that count. | Hard8 | Dynamic programmingPrefix sum+1 | No attempts yet | 30s | 1536 MB | Judgeable |
| Bulb NumberGiven wires connecting switches to bulbs where crossing wires turn bulbs off when pressed together, find the K-th smallest binary number achievable by some subset of pressed switches. | Hard8 | Bit manipulationGreedy+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Tree PartitionChoose exactly K vertices in a weighted tree to minimize the total weight of edges whose endpoints share the same chosen/unchosen status, and output the chosen vertex set. | Hard8 | Dynamic programmingTree+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Cargo Truck Collection RoutesGiven a tree rooted at the depot with cargo weights at nodes, plan truck trips of capacity 10 minimizing total travel distance, splitting cargo as needed, and output the routes. | Hard8 | TreeGreedy+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Final Group PhotoCount the ways to fill a decreasing-width staircase of rows (back rows longer) with distinct heights so rows decrease left to right and columns decrease from back to front, essentially counting standard Young tableaux for a skew shape. | Hard8 | CombinatoricsMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Mars Bacteria LineupGiven a repulsion matrix, choose left/right swap at every node of a complete binary tree to minimize the total sum of adjacent-pair distances in the resulting leaf permutation. | Hard8 | Dynamic programmingTree+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Stack Truck DriverCount length-bounded walks from city 1 to city N in a graph where edges push or pop letters on a stack, with pops requiring a matching top element. | Hard8 | Dynamic programmingStack+1 | No attempts yet | 3s | 128 MB | Judgeable |
| Bishop DoodleSimulate two bishops on a 2N by 2N board moving K times to maximize the sum of newly-seen cells not previously visible to either bishop. | Hard8 | Dynamic programmingSimulation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| I Am a Great Superstar KGiven N contestants' scores in M genres (each genre's scores listed sorted), pick K contestant-genre assignments (one genre per chosen contestant) maximizing total score, requiring a min-cost/max-flow or matroid intersection style greedy insight. | Hard8 | GreedyGraph+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Black RectanglesCount unordered pairs of disjoint all-black axis-aligned rectangles (each containing at least two cells) in an up to 1000x1000 grid, modulo 10007. | Hard8 | Prefix sumCombinatorics+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Buying Pancake IngredientsCount walks from node 1 back to node 1 within K minutes on a directed graph where each edge can be crossed cheaply or with a shop visit collecting a subset of 4 ingredients, requiring all four collected, using state (node, ingredient mask) matrix exponentiation over a huge K. | Hard8 | MatrixDynamic programming+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Parcel DeliveryFind minimum total cell-cost to visit an ordered sequence of targets on a grid where vertical movement is restricted to the first and last columns. | Hard8 | Shortest pathDynamic programming+1 | No attempts yet | 2s | 256 MB | Judgeable |
| Watermelon Throwing GameSimulate a watermelon-throwing process over up to 1e9 periods among 20 students, where each student's throw count parity depends on watermelons received, requiring matrix exponentiation or cycle detection to compute the total thrown. | Hard8 | MatrixDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Apple CountGiven range [A,B] up to 10^15, sum for each number a value derived from run-length groups of equal digits, using digit-DP for efficiency. | Hard8 | Dynamic programmingMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Periodic TableCount ways to place K non-attacking pieces on a histogram-shaped grid where two cells in the same row are close only if all columns between them reach that row, modulo 1e9+7. | Hard8 | Dynamic programmingStack+1 | No attempts yet | 1s | 128 MB | Judgeable |
| GrasshopperGiven an N×N grid and a special knight-like move rule requiring strictly increasing petal counts, find the longest such path starting from a given cell. | Hard8 | Dynamic programmingMatrix+1 | No attempts yet | 4s | 128 MB | Judgeable |
| Wangnuni the FrogFind the path from leaf 1 to leaf N using only rightward or upward axis-aligned jumps costing K power each, that maximizes leftover power after eating flies along the way. | Hard8 | Dynamic programmingSorting+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Bicycle RaceGiven a graph where every edge belongs to at most one cycle, find the longest walk ending at city 1 using each edge at most once. | Hard8 | TreeDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Allowed Digit MultiplesCount multiples of X within [A,B] whose decimal digits all come from an allowed digit set, with values up to 10^11. | Hard8 | Dynamic programmingMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Buying a HighwayGiven road segment purchase costs and trucks with routes and toll fees under a per-segment per-direction traffic cap K, minimize total cost of buying segments plus tolls paid. | Hard8 | GraphShortest path+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Building a WallGiven block sizes/costs and two target wall silhouettes for horizontal and vertical placement days, compute the minimum total cost to build the wall over two days. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Mouse TrapsGiven an N x N grid of trap counts, choose K consecutive cells per row to remove so no path exists left-to-right or top-to-bottom, maximizing removed traps. | Hard8 | Dynamic programmingMatrix+1 | No attempts yet | 1s | 128 MB | Judgeable |
| ScientistGiven a grid maze and a sequence of box-shift events caused by a hidden mouse pushing box edges, compute the minimum number of mouse moves consistent with the observed box movements. | Hard8 | BFSDynamic programming+1 | No attempts yet | 2s | 128 MB | Judgeable |
| ElephantGiven N distinct 2D points, find the length of the longest strictly increasing chain in both coordinates and count how many such maximum chains exist modulo 1e9+7. | Hard8 | Dynamic programmingSorting+1 | No attempts yet | 3s | 128 MB | Judgeable |
| Tetris-Like GameGiven a score table for consecutive-letter group sizes, decide optimally which of three stack-like columns to drop each incoming letter into to maximize the total column score. | Hard8 | Dynamic programmingImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Banner SchedulingGiven N banner requests with fixed relative display-day patterns spanning at most 7 days, arriving in order with non-decreasing start days, find the minimum schedule length using at most K banner slots per day. | Hard8 | Dynamic programmingGreedy+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Martian DNA FormulaCompress a DNA string into the shortest possible run-length style notation using nested parentheses with repeat counts. | Hard8 | Dynamic programmingString+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Ships on a RiverGiven river fields with fish amounts and ships each needing a fixed anchor field and length placed without overlap, maximize total fish covered. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Loading Cattle onto Freight CarsPartition a sequence of animals into up to K contiguous car groups of size at most M, resolving chained attacker/protector fights inside each car, to maximize survivors. | Hard8 | Dynamic programmingSimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| GameGiven a grid game where two players alternately move a token down, right, or diagonally with scoring foods, determine for each starting cell which player wins under optimal play. | Hard8 | Dynamic programmingGame theory+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Wedding TrainArrange N guests in a line minimizing total adjacent height difference while keeping K given family members in a fixed relative order. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Sailing RaceFind the longest simple path on a circular arrangement of harbors using directed edges so that chords never cross except possibly one crossing involving the first stage, and report the max length with smallest starting harbor. | Hard8 | Dynamic programmingGeometry+1 | No attempts yet | 3s | 32 MB | Judgeable |
| Insertion Sort vs Quicksort ComparisonsCount permutations of 1..N where insertion sort's comparison count exceeds quicksort's by between 1 and X, modulo 1234567. | Hard8 | Dynamic programmingCombinatorics+2 | No attempts yet | 1s | 128 MB | Judgeable |
| FenceChoose a subset of given points to form a convex polygon fence minimizing 20 times the number of posts used plus 111 times the number of trees left outside, considering all possible fences. | Hard8 | GeometryDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Choosing Orders and Renting MachinesGiven orders with income and per-machine rent costs plus fixed machine purchase prices, choose orders and buy/rent decisions to maximize profit, solvable as a max-flow min-cut project selection problem. | Hard8 | GraphGreedy+1 | No attempts yet | 2s | 128 MB | Judgeable |
| ConnectGiven a maze-like board with figures placed in rooms, pair up all figures and connect each pair with vertex-disjoint paths minimizing total path length. | Hard8 | GraphShortest path+1 | No attempts yet | 0.5s | 32 MB | Judgeable |
| Mobile ServiceGiven a cost matrix and a request sequence, find the minimum total cost of moving three servers to serve each request in order using optimal dynamic programming. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 3s | 128 MB | Judgeable |
| MonumentFind the maximum surface area 4ab of an axis-aligned a x a x b box of all-normal unit cubes that fits in a 3D grid with pores, where the square face can align with any of three axes. | Hard8 | Binary searchMatrix+2 | No attempts yet | 5s | 128 MB | Judgeable |
| RLE CompressionDecode a custom run-length encoding scheme and compute the minimum possible length of any code that decodes to the same character sequence. | Hard8 | Dynamic programmingString+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Moving RobotsGiven several robots each with a bounded command sequence, find the minimum total deletions so all robots can be made to stop at one common grid cell, breaking ties by lexicographically smallest position. | Hard8 | Dynamic programmingSimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Honeycomb Maximum Route SumFind the maximum sum path through a hexagonal grid moving diagonally down-left or down-right, allowing one row to have its maximum value moved to any position once. | Hard8 | Dynamic programmingMatrix+1 | No attempts yet | 1s | 128 MB | Judgeable |
| InsultsParse a string against a context-free grammar defining insults, then find the lexicographically next same-length valid insult or report invalid/ultimate. | Hard8 | StringDynamic programming+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Hexagonal ParcelsOn a hexagonal grid with four labeled connected regions, find the minimum number of free cells to buy so all four regions become one connected component (Steiner-tree style optimization on a hex graph). | Hard8 | GraphBFS+1 | No attempts yet | 1s | 128 MB | Judgeable |
| BundlingGiven permitted bundle templates and a dependency chain among instructions, compute the minimum number of bundles to pack the sequence and, among those, the minimum number of stops needed. | Hard8 | Dynamic programmingGreedy+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Minimizing MaximizerGiven a pipeline of range-sort operations, find the minimum number of operations (kept in order) whose composition still guarantees the last position always holds the overall maximum. | Hard8 | GreedyIntervals+1 | No attempts yet | 1s | 512 MB | Judgeable |
| ChoirCompute minimum-cost assignment of singers to positions between all song pairs, then find the song ordering (TSP over at most 6 songs) that minimizes total replacements. | Hard8 | Dynamic programmingCombinatorics+1 | No attempts yet | 3s | 512 MB | Judgeable |
| Immediate DeliveryGiven a small weighted graph (n ≤ 18), split all junctions between two drivers starting from node 1 so that the larger of their two walk-covering times from node 1 is minimized. | Hard8 | Bit manipulationDynamic programming+2 | No attempts yet | 3s | 256 MB | Judgeable |
| King of OperationsGiven a custom digit-wise binary operator table, compute the repeated left-to-right combination of all numbers from a to b (up to 10^18) using digit dynamic programming per digit position. | Hard8 | Dynamic programmingMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Cactus RevolutionDecide whether a given cactus graph can be split into k connected districts of equal size n/k, using cactus structure properties. | Hard8 | GraphDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |
| JourneyGiven two graphs with shortest distances to a target node, find the longest alternating walk where each move strictly decreases the current graph's distance-to-target value, or report infinite. | Hard8 | Shortest pathDynamic programming+1 | No attempts yet | 3s | 256 MB | Judgeable |
| Just Too LuckyCount integers from 1 to n (up to 10^12) whose value is divisible by its own digit sum, requiring digit-DP over fixed digit-sum targets. | Hard8 | Dynamic programmingCombinatorics+1 | No attempts yet | 3s | 256 MB | Judgeable |
| Fund ManagementGiven daily prices for up to 8 stocks over up to 100 days, decide one buy/sell/hold action per day under per-stock and total lot caps to maximize final cash after closing all positions. | Hard8 | Dynamic programmingSimulation+1 | No attempts yet | 3s | 128 MB | Judgeable |
| Cross and CrossFor a 1×n board where players alternately mark cells and the first to make three consecutive marks wins, decide the winner under optimal play for given n up to 2000. | Hard8 | Game theoryDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Domestic NetworksChoose a spanning tree of apartments and assign each edge to one of two cable types with limited total lengths to minimize cost, or report impossibility. | Hard8 | Minimum spanning treeDynamic programming+1 | No attempts yet | 2s | 64 MB | Judgeable |
| InterconnectGiven an initial graph on up to 30 towns, compute the exact expected number of random-edge additions needed until the graph becomes fully connected, as a reduced fraction. | Hard8 | Union-findMath+2 | No attempts yet | 1s | 128 MB | Judgeable |
| BridgesChoose k edges of a weighted tree to convert to a faster speed so that the sum of travel times over all pairs is minimized, breaking ties lexicographically. | Hard8 | TreeGreedy+2 | No attempts yet | 2s | 64 MB | Judgeable |
| Bee GardenGiven a tree of hives with coordinates, find which single new edge added minimizes the doubled-tree traversal, i.e. maximizes edge weight removed twice minus new edge distance, tie-broken lexicographically. | Hard8 | TreeDynamic programming+1 | No attempts yet | 2s | 64 MB | Judgeable |
| Train DelaysGiven a train timetable with hourly departures and probabilistic delays, compute the minimum expected total travel time from start to destination as an exact fraction. | Hard8 | Shortest pathDynamic programming+2 | No attempts yet | 5s | 128 MB | Judgeable |
| Selling LandFor every grid cell (as a rectangle's bottom-right corner), find the maximum perimeter of an all-grass rectangle ending there, then output counts grouped by perimeter. | Hard8 | Dynamic programmingArray+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Ticket to RideGiven a weighted graph and four pairs of terminal cities, find the minimum total edge cost of a subgraph connecting all four pairs simultaneously. | Hard8 | GraphMinimum spanning tree+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Secret Code: Largest NumberGiven a noisy string, find the largest decimal number it could decode to, either fixing one language for all digits or allowing a different language per digit, using digit-word subsequence matching. | Hard8 | Dynamic programmingString matching+2 | No attempts yet | 3s | 128 MB | Judgeable |
| Software Industry RevolutionGiven a wildcard pattern (with ? and *) and a text, find the minimum-complexity substring of the text that matches the whole pattern, or report impossible. | Hard8 | String matchingDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |
| ACGUGiven an RLE-encoded RNA-like string, find the maximum number of non-crossing A-U and C-G pairs with at most K C-G pairs, exploiting the special RLE size constraints. | Hard8 | Dynamic programmingString+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Balloon CollectionGiven balloons falling at specific positions and times, find the minimum weighted travel cost for a capacity-3 robot to catch and store all balloons at the origin, or report the first uncatchable balloon. | Hard8 | Dynamic programmingGreedy+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Twenty QuestionsGiven n objects each described by m binary features, find the minimum worst-case number of adaptive yes/no feature queries needed to identify the hidden object. | Hard8 | Bit manipulationDynamic programming+1 | No attempts yet | 1s | 128 MB | Judgeable |