Problems

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Total results29,440 problems

Necklace Sequence
Medium6
String, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Go Territory
Medium6
Brute force, BFS+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Water Pipe Construction
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Nth Largest Number
Medium6
Binary search, Matrix+1
No attempts yet
Time limit
1s
Memory limit
12 MB
Judgeable
Palindrome Partition
Medium6
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Choosing Weight Masses
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Degree Sequence
Medium6
Greedy, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Ciphertext
Medium6
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Number of Multisets
Medium6
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Game of Death
Medium6
Graph, Matrix+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Restore an Orthogonal Polygon
Medium6
Geometry, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Choosing a Subarray
Medium6
Stack, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Lecture Tour
Medium6
Greedy, Union-find+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Cactus Graph
Medium6
Graph, DFS+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Shortest Uncommon Subsequence
Medium6
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Gallery
Medium6
Greedy, Matrix+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Stacking Dice
Medium6
Dynamic programming, Simulation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Two Towers
Medium6
Binary search, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Rectangles for Four Friends
Medium6
Hash map, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Building a Human Tower
Medium6
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Water Level in Connected Tanks
Medium6
Binary search, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Robot Commands
Medium6
Simulation, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Warehouse Relocation
Medium6
Greedy, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Strongly Connected Components
Medium6
Graph, DFS
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Mirror Installation
Medium6
BFS, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Line Segment Groups
Medium6
Union-find, Geometry+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Robot Navigation
Medium6
Dynamic programming, Matrix+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Palindrome Paths
Medium6
Dynamic programming, Matrix+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Making Onion Chips
Medium6
Simulation, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Reasonable Paths
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Payroll Calculation
Medium6
Greedy, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Fire Station Dilemma
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Walking the Dog
Medium6
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Choosing Points 2
Medium6
Array, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Binary XOR
Medium6
Bit manipulation, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Molecule Decomposition
Medium6
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Bus and Passengers
Medium6
Greedy, Intervals+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Find the K-th Pinary Number
Medium6
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Rock Paper Scissors
Medium6
Graph, Union-find+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Network Recovery
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
2s
Memory limit
192 MB
Judgeable
Matchsticks and Squares
Medium6
Matrix, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Circular Network
Medium6
Greedy, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Security System Installation
Medium6
Minimum spanning tree, Graph+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Work Process
Medium6
Tree, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Ice Cream
Medium6
Sorting, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Gold Coin Collection
Medium6
Greedy, Simulation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Binary Number
Medium6
String, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Divide Intervals
Medium6
Dynamic programming, Array
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Mines
Medium6
Greedy, Simulation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Apple Tree
Medium6
Tree, Stack+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Castle
Medium6
BFS, Graph+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
GPS Encoding
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sudoku
Medium6
Backtracking, Matrix+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Camelot Gathering
Medium6
BFS, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Making a Triangle
Medium6
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Candy Box
Medium6
Segment tree, Binary search+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Minkowski Sum
Medium6
Geometry, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Tidying Arrays
Medium6
Graph, Union-find+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Olympic Ranking
Medium6
Brute force, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Chopsticks
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Butcher Shop
Medium6
Sorting, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Mole Catching
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Closest Pair of Points
Medium6
Divide and conquer, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Liars
Medium6
Union-find, Graph+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Safe Drop Test
Medium6
Dynamic programming, Binary search+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Bus Timetable
Medium6
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lamps
Medium6
Bit manipulation, Math+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Conflicting Strings
Medium6
Greedy, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Water Filling
Medium6
Heap, Matrix+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Graph Reconstruction
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Death Note
Medium6
Dynamic programming, Greedy
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Cutting Intervals
Medium6
Binary search, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Nonlinear Sequences
Medium6
Backtracking, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Monodigital Expression
Medium6
Dynamic programming, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Honeycomb
Medium6
Math, Binary search+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Base Stations
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Seat Arrangement
Medium6
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Gene
Medium6
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Roadblock Inspection
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Adventure Game
Medium6
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Find Direct Supervisors
Medium6
Sorting, Tree+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
String Reconstruction
Medium6
Dynamic programming, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Word Chain
Medium6
Bit manipulation, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Dumbbell Sorting
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Ant-Elephant War
Medium6
Shortest path, Graph
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Minimum Edit Distance 2
Medium6
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Team Running Selection
Medium6
Dynamic programming, Binary search+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Phone Number Mnemonics
Medium6
Dynamic programming, String matching+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Survival and Escape
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Farmer
Medium6
Dynamic programming, Greedy
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Remarkable Students
Medium6
Sorting, Divide and conquer+2
No attempts yet
Time limit
2s
Memory limit
192 MB
Judgeable
Mirror Rays
Medium6
Simulation, Matrix+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Mine Removal
Medium6
Simulation, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Wireless Communication Base Stations
Medium6
Backtracking, Graph+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Grand Canal
Medium6
Union-find, Minimum spanning tree+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Unknown Polygon
Medium6
Graph, DFS+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Keyboard Typo
Medium6
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Party
Medium6
Graph, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Mayor Election Posters
Medium6
Segment tree, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
192 MB
Judgeable
Fibonacci Game
Medium6
Game theory, Number theory+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Necklace SequenceDecompose a binary string into a strictly decreasing sequence of Lyndon-like necklace factors where adjacent concatenations fail the necklace property.	Medium6	StringGreedy+1	No attempts yet	2s	128 MB	Judgeable
Go TerritoryReconstruct a unique black/white Go board from row, column, and both diagonal stone counts, then flood-fill empty regions to count enclosed territory.	Medium6	Brute forceBFS+1	No attempts yet	2s	128 MB	Judgeable
Water Pipe ConstructionSelect a subset of pipes with lengths summing exactly to D that maximizes the minimum capacity among chosen pipes.	Medium6	Dynamic programmingGreedy+1	No attempts yet	2s	128 MB	Judgeable
Nth Largest NumberGiven an N x N matrix where each column is sorted top to bottom, find the Nth largest value among all N^2 entries efficiently.	Medium6	Binary searchMatrix+1	No attempts yet	1s	12 MB	Judgeable
Palindrome PartitionGiven a lowercase string up to length 2000, find the minimum number of palindromic substrings it can be partitioned into.	Medium6	Dynamic programmingString	No attempts yet	2s	128 MB	Judgeable
Choosing Weight MassesAssign integer masses to N weights satisfying M difference inequality constraints, detecting infeasibility, using shortest-path style constraint graph construction.	Medium6	Shortest pathGraph+1	No attempts yet	2s	128 MB	Judgeable
Degree SequenceGiven a target degree sequence for N vertices, construct any simple graph's adjacency matrix matching it exactly, or report impossibility.	Medium6	GreedyGraph+2	No attempts yet	2s	128 MB	Judgeable
CiphertextGiven up to 40 positive integers and a target K, find a subset (as a bitstring) whose sum equals K, exploiting the small total sum with meet-in-the-middle or subset-sum search.	Medium6	Dynamic programmingBit manipulation+1	No attempts yet	2s	128 MB	Judgeable
Number of MultisetsGiven multiplicities of values from 1 to T among A numbers, count multisets of size K for S≤K≤B modulo 1,000,000.	Medium6	Dynamic programmingCombinatorics+1	No attempts yet	2s	128 MB	Judgeable
Game of DeathGiven a directed graph where each of N people points to two others, determine for M queries if b can be reached from a in exactly K steps.	Medium6	GraphMatrix+1	No attempts yet	3s	256 MB	Judgeable
Restore an Orthogonal PolygonGiven the unordered vertices of an orthogonal (axis-aligned) polygon, reconstruct the boundary order and output its perimeter length.	Medium6	GeometrySorting+1	No attempts yet	2s	128 MB	Judgeable
Choosing a SubarrayGiven an array, find the contiguous subarray that maximizes the product of its sum and its minimum element.	Medium6	StackPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
Lecture TourGiven jobs each with a fee and a deadline, schedule at most one job per day to maximize total fee collected before deadlines.	Medium6	GreedyUnion-find+1	No attempts yet	2s	128 MB	Judgeable
Cactus GraphGiven a graph described by edge-paths, verify it is a cactus and count connected spanning subgraphs that remain cactus graphs.	Medium6	GraphDFS+1	No attempts yet	2s	128 MB	Judgeable
Shortest Uncommon SubsequenceGiven two strings, compute the length of the shortest subsequence of A that is not a subsequence of B.	Medium6	Dynamic programmingString	No attempts yet	2s	128 MB	Judgeable
GalleryGiven a grid of walls and empty cells, compute the maximum number of double-cell-length pictures that can be hung on wall faces adjacent to empty space without overlapping.	Medium6	GreedyMatrix+1	No attempts yet	2s	128 MB	Judgeable
Stacking DiceGiven N dice with fixed opposite-face pairs, choose orientations so that stacked dice match top-to-bottom faces and maximize the sum of one vertical column of side numbers.	Medium6	Dynamic programmingSimulation+1	No attempts yet	2s	128 MB	Judgeable
Two TowersGiven segment lengths of a cycle of N points, find two points maximizing the shorter of the two circular path distances between them.	Medium6	Binary searchPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
Rectangles for Four FriendsGiven up to 500,000 distinct points, count axis-aligned rectangles with fixed side lengths A and B whose corners are all present in the point set.	Medium6	Hash mapTwo pointers+1	No attempts yet	2s	128 MB	Judgeable
Building a Human TowerGiven weights and strengths of N acrobats, order them into a tower to minimize the maximum of (weight above - strength) over all acrobats.	Medium6	GreedySorting	No attempts yet	2s	128 MB	Judgeable
Water Level in Connected TanksGiven N tanks with different base heights and cross-sections connected at the bottom, compute the common water level after pouring V units of water, or report overflow if capacity is exceeded.	Medium6	Binary searchSorting+1	No attempts yet	2s	128 MB	Judgeable
Robot CommandsConvert an old robot's forward/turn/scan command sequence into a minimal equivalent sequence for a new robot with directional move and scan commands producing the same scanned cells in order.	Medium6	SimulationGreedy+1	No attempts yet	2s	128 MB	Judgeable
Warehouse RelocationGiven item counts on old warehouse floors and capacities on new warehouse floors plus a worker limit k, find the maximum items transportable and the minimum total cost (sum of a+b per job) achieving that maximum.	Medium6	GreedyMath+1	No attempts yet	2s	128 MB	Judgeable
Strongly Connected ComponentsCompute all strongly connected components of a directed graph with up to 10,000 vertices and 100,000 edges, printing each component sorted, ordered by its smallest vertex.	Medium6	GraphDFS	No attempts yet	2s	128 MB	Judgeable
Mirror InstallationFind the minimum number of 45-degree mirrors needed on a grid so light travels from one door to the other, treating direction changes as costs in a shortest-path search.	Medium6	BFSShortest path+1	No attempts yet	2s	128 MB	Judgeable
Line Segment GroupsGiven N line segments, group them by connectivity (segments that touch or cross belong together) and output the number of groups and the size of the largest group.	Medium6	Union-findGeometry+1	No attempts yet	2s	128 MB	Judgeable
Robot NavigationGiven an N x M grid, find the maximum sum path from top-left to bottom-right moving only left, right, or down without revisiting cells.	Medium6	Dynamic programmingMatrix+1	No attempts yet	1s	512 MB	Judgeable
Palindrome PathsCount length-L walks on an N x N grid with 8-directional moves whose visited digit sequence forms a palindrome.	Medium6	Dynamic programmingMatrix+1	No attempts yet	2s	128 MB	Judgeable
Making Onion ChipsRepeatedly find and remove the rectangular frame (perimeter cells only) with maximum sum from an N×N grid using only remaining cells, M times.	Medium6	SimulationBrute force+1	No attempts yet	2s	128 MB	Judgeable
Reasonable PathsGiven a weighted undirected graph, count paths from vertex 1 to vertex 2 where each step moves to a vertex strictly closer to vertex 2 by shortest-path distance.	Medium6	Shortest pathGraph+1	No attempts yet	2s	128 MB	Judgeable
Payroll CalculationGiven counts of divisible denominations, determine the maximum number of testers payable at least C won each without splitting cash items.	Medium6	GreedyMath+1	No attempts yet	2s	128 MB	Judgeable
Fire Station DilemmaOrder fires with linear extinguish-time growth a·t+b to minimize total finish time, then output it modulo 40000.	Medium6	GreedySorting+1	No attempts yet	2s	128 MB	Judgeable
Walking the DogCompute total signed angle swept around the origin as a sequence of points connects via shortest arcs, then floor the number of full rotations.	Medium6	GeometryMath+1	No attempts yet	2s	128 MB	Judgeable
Choosing Points 2Given up to 100 points and a fixed rectangle width A and height B, find the placement that covers the maximum number of points, including boundary points.	Medium6	ArraySorting+1	No attempts yet	2s	128 MB	Judgeable
Binary XORGiven binary strings, find the closest achievable XOR combination (using at least one XOR) to a target, breaking ties by fewest operations then lexicographic order.	Medium6	Bit manipulationMath+1	No attempts yet	2s	128 MB	Judgeable
Molecule DecompositionFind the minimum number of edge cuts on a tree needed to isolate a connected subtree of exactly M nodes.	Medium6	TreeDynamic programming+1	No attempts yet	2s	128 MB	Judgeable
Bus and PassengersGiven up to 50000 requested one-directional bus segments and a bus of capacity C on a route of N stops, maximize the total number of passengers carried in one round trip without exceeding capacity at any point.	Medium6	GreedyIntervals+1	No attempts yet	2s	128 MB	Judgeable
Find the K-th Pinary NumberGiven K up to 10^18, output the K-th smallest binary string with no leading zero and no two consecutive 1s, treated as a number by value order.	Medium6	Dynamic programmingCombinatorics+1	No attempts yet	2s	128 MB	Judgeable
Rock Paper ScissorsGiven N students each with two literal-style predictions (turn, gesture) among only rock/scissors, decide if a gesture sequence exists satisfying at least one prediction per student, essentially 2-SAT.	Medium6	GraphUnion-find+1	No attempts yet	2s	128 MB	Judgeable
Network RecoveryGiven a weighted graph, find a minimum edge subset that preserves all shortest-path distances from node 1 while keeping the graph connected.	Medium6	Shortest pathGraph+1	No attempts yet	2s	192 MB	Judgeable
Matchsticks and SquaresGiven a grid of matchsticks drawn with horizontal and vertical line segments, count all squares of any size whose four full sides are present.	Medium6	MatrixBrute force+1	No attempts yet	1s	128 MB	Judgeable
Circular NetworkGiven a cycle of N nodes and P path requests, choose a direction for each request to minimize the total number of distinct cycle edges converted.	Medium6	GreedyBit manipulation+1	No attempts yet	2s	128 MB	Judgeable
Security System InstallationBuild a minimum spanning tree from the given network, then find the vertex minimizing the sum of shortest distances to all other vertices within that tree.	Medium6	Minimum spanning treeGraph+1	No attempts yet	2s	128 MB	Judgeable
Work ProcessGiven a tree of supervisors, compute the tree height and the maximum number of nodes removable while keeping tasks completable within that same height using limited workers per time slot.	Medium6	TreeGreedy+1	No attempts yet	2s	128 MB	Judgeable
Ice CreamGiven a full pairwise preference tournament on n up to 1000 items, output an ordering where each item is at least as preferred as the next, or report impossibility.	Medium6	SortingGreedy+1	No attempts yet	2s	128 MB	Judgeable
Gold Coin CollectionGiven a time budget and monsters that approach while coins are collected and retreat while waiting, find the maximum coins collectible over a schedule of collect/wait turns without ever letting a monster reach Jimin.	Medium6	GreedySimulation+1	No attempts yet	2s	128 MB	Judgeable
Binary NumberGiven N up to 1000, count consecutive-zero groups in the N-th generation of the Thue-Morse-like doubling sequence without building the exponentially large string.	Medium6	StringMath+1	No attempts yet	2s	128 MB	Judgeable
Divide IntervalsSelect exactly M non overlapping, non adjacent intervals from an array of up to 100 integers to maximize the total sum.	Medium6	Dynamic programmingArray	No attempts yet	2s	128 MB	Judgeable
MinesGiven N mines in a line with chain-reaction explosion rules based on impact strength, find the minimum set of mines to directly detonate so all mines explode.	Medium6	GreedySimulation+1	No attempts yet	2s	128 MB	Judgeable
Apple TreeGiven a DFS 0/1 traversal string of a tree and two marked positions, find the smallest subtree (by matching visit/return indices) that contains both marked vertices.	Medium6	TreeStack+1	No attempts yet	2s	128 MB	Judgeable
CastleGiven a grid castle with walls encoded per cell, find the number of rooms, the largest room's area, and the best merged area after removing exactly one wall.	Medium6	BFSGraph+1	No attempts yet	2s	128 MB	Judgeable
GPS EncodingGiven a letter permutation encoding numbers 0-25, find the shortest way to encode a digit string as letters using single digits or valid two-digit pairs, breaking ties by lexicographically largest result.	Medium6	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
SudokuSolve a given 9x9 Sudoku puzzle via backtracking and output the lexicographically smallest completed board if multiple solutions exist.	Medium6	BacktrackingMatrix+1	No attempts yet	2s	256 MB	Judgeable
Camelot GatheringCompute BFS knight-move distances from every piece to every square, and find the meeting square and rendezvous strategy minimizing total moves to gather king and knights, where the king can ride a knight after meeting it.	Medium6	BFSShortest path+1	No attempts yet	2s	128 MB	Judgeable
Making a TriangleGiven up to 40 sticks, partition all of them into three groups whose summed lengths form a triangle, maximizing the triangle's area via Heron's formula.	Medium6	Dynamic programmingCombinatorics+1	No attempts yet	2s	128 MB	Judgeable
Candy BoxSupport adding or removing counts of flavored candies and querying/removing the k-th smallest flavor efficiently, using a Fenwick tree with binary search.	Medium6	Segment treeBinary search+1	No attempts yet	2s	128 MB	Judgeable
Minkowski SumGiven two convex polygons up to 1000 vertices, compute their Minkowski sum polygon printed in counterclockwise order starting from a canonical vertex.	Medium6	GeometrySorting+1	No attempts yet	2s	128 MB	Judgeable
Tidying ArraysGiven two arrays of 1..N, find the minimum number of index swaps between A and B so neither array has duplicate values, or report impossibility.	Medium6	GraphUnion-find+1	No attempts yet	2s	128 MB	Judgeable
Olympic RankingFor each Olympic team, find the medal weight values (99 ≥ gold > silver > bronze ≥ 1) that give the best possible ranking, breaking ties by smallest ggssbb number.	Medium6	Brute forceSorting+1	No attempts yet	1s	128 MB	Judgeable
ChopsticksGiven N chopstick lengths, pick 3K of them and group into K triples to minimize the sum of squared differences between the two smallest lengths in each triple.	Medium6	Dynamic programmingSorting+1	No attempts yet	2s	128 MB	Judgeable
Butcher ShopGiven N meat pieces with weight and price, find the minimum cost so that buying one piece and receiving all strictly cheaper pieces free reaches a target total weight M.	Medium6	SortingPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
Mole CatchingGiven N moles with positions and appearance times, find the maximum number Jeongeun can catch by moving at speed at most S from origin at time 0.	Medium6	Dynamic programmingSorting+1	No attempts yet	2s	128 MB	Judgeable
Closest Pair of PointsGiven up to 100,000 points, compute the minimum squared distance between any two points efficiently.	Medium6	Divide and conquerSorting+1	No attempts yet	1s	256 MB	Judgeable
LiarsUse union-find with parity on statements to split islanders into two groups, then check if group sizes matching p1/p2 uniquely determine the good tribe.	Medium6	Union-findGraph+1	No attempts yet	2s	128 MB	Judgeable
Safe Drop TestGiven N floors and K identical safes, compute the minimum number of drops needed in the worst case to find the critical breaking floor.	Medium6	Dynamic programmingBinary search+1	No attempts yet	2s	128 MB	Judgeable
Bus TimetableGenerate bus timetables for multiple routes and repeated services per scenario, formatting stop times into aligned columns sorted by departure time.	Medium6	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
LampsGiven N lamps in a circle updating by XOR with the right neighbor each second, compute the states after M steps efficiently using binary exponentiation over XOR shifts.	Medium6	Bit manipulationMath+1	No attempts yet	5s	128 MB	Judgeable
Conflicting StringsDecide, for each set of equal-length strings with wildcard '*', whether removing at most k strings can make every position agree on one letter.	Medium6	GreedyString+1	No attempts yet	1s	128 MB	Judgeable
Water FillingGiven a grid of terrain heights, compute the maximum water volume trapped inside using a boundary-based priority-queue flood fill (trapping rain water 2D).	Medium6	HeapMatrix+1	No attempts yet	2s	128 MB	Judgeable
Graph ReconstructionGiven all pairwise shortest distances of a connected weighted graph, reconstruct a graph with exactly M edges that reproduces those distances or report impossibility.	Medium6	GraphShortest path+1	No attempts yet	2s	128 MB	Judgeable
Death NoteGiven word lengths that must be placed in order into fixed-width rows with single spaces between words, minimize the sum of squared leftover cells for all rows except the last.	Medium6	Dynamic programmingGreedy	No attempts yet	2s	128 MB	Judgeable
Cutting IntervalsGiven N intervals, find cut points A and B minimizing A then B so the total overlapped length inside [A,B] equals exactly K, or output 0 0.	Medium6	Binary searchPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
Nonlinear SequencesCount and list increasing length-L sequences from 1..M containing no three-term arithmetic progression, printing the first three lexicographically and the total count.	Medium6	BacktrackingCombinatorics+1	No attempts yet	2s	128 MB	Judgeable
Monodigital ExpressionCompute, for repeated digit K and concatenations plus arithmetic operators, the minimum number of K digits needed to build each queried integer (or report NO if it exceeds 8).	Medium6	Dynamic programmingMath+1	No attempts yet	2s	128 MB	Judgeable
HoneycombGiven a hexagonal spiral numbering of honeycomb cells centered at 1, compute the minimum number of rooms on a shortest path from room 1 to room N.	Medium6	MathBinary search+1	No attempts yet	2s	128 MB	Judgeable
Base StationsGiven points off a line, place axis-aligned squares centered on the x-axis to cover all points while minimizing the total side length sum.	Medium6	Dynamic programmingSorting+2	No attempts yet	2s	128 MB	Judgeable
Seat ArrangementCount the ways to seat N-1 ticket holders into N seats, given one free seat, so that each person sits in their own, adjacent, or the free seat.	Medium6	Dynamic programmingCombinatorics+1	No attempts yet	2s	128 MB	Judgeable
GeneFind the maximum-length subsequence of a DNA string that can be built by the given nested and concatenated matching-pair grammar (like balanced parentheses with a/t and g/c pairs).	Medium6	Dynamic programmingString	No attempts yet	2s	128 MB	Judgeable
Roadblock InspectionGiven a weighted graph, find the maximum increase in shortest path from node 1 to node N caused by removing a single edge, outputting -1 if removal can disconnect them.	Medium6	Shortest pathGraph+1	No attempts yet	1s	128 MB	Judgeable
Adventure GameGiven a maze of rooms with gold-boosting or gold-costing conditions, decide if room n is reachable from room 1 following graph edges under gold constraints.	Medium6	GraphBFS+1	No attempts yet	1s	128 MB	Judgeable
Find Direct SupervisorsGiven employees with salary and tenure, build a supervisor hierarchy by nearest dominating employee and answer queries for direct supervisor and subtree subordinate counts.	Medium6	SortingTree+1	No attempts yet	2s	128 MB	Judgeable
String ReconstructionCount length-L strings over an alphabet such that every length-k substring belongs to a given allowed set, solved via automaton/DP over overlaps.	Medium6	Dynamic programmingString+1	No attempts yet	2s	128 MB	Judgeable
Word ChainGiven up to 16 vowel-only words, chain them by matching first and last letters without repeats to maximize the total length used.	Medium6	Bit manipulationDynamic programming+1	No attempts yet	2s	128 MB	Judgeable
Dumbbell SortingFind the minimum total cost of swaps (cost = sum of the two swapped weights) needed to sort an array of distinct weights into increasing order.	Medium6	GreedySorting+1	No attempts yet	2s	128 MB	Judgeable
Ant-Elephant WarGiven a weighted graph, find which single edge to delete so that the resulting shortest path from vertex 1 to vertex N is as long as possible.	Medium6	Shortest pathGraph	No attempts yet	2s	256 MB	Judgeable
Minimum Edit Distance 2Compute the minimum number of insert, delete, replace, and adjacent-swap operations to transform string X into string Y.	Medium6	Dynamic programmingString	No attempts yet	2s	128 MB	Judgeable
Team Running SelectionSelect a subset of students whose heights sum exactly to H while maximizing the minimum running speed among chosen members.	Medium6	Dynamic programmingBinary search+1	No attempts yet	2s	128 MB	Judgeable
Phone Number MnemonicsFind the minimum number of dictionary words whose digit encodings concatenate to exactly match a given phone number, using the letter to digit telephone mapping.	Medium6	Dynamic programmingString matching+1	No attempts yet	2s	128 MB	Judgeable
Survival and EscapeChoose for each time-ordered box whether to eat it for HP or stack it for height, to survive as long as possible while reaching stack height D as early as possible.	Medium6	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
FarmerGiven a budget Q of cypress trees selectable from cyclic gardens and linear furrows, maximize total olive trees gained where a full garden gives n olives but a partial selection from a garden or any furrow segment gives one less than the count chosen.	Medium6	Dynamic programmingGreedy	No attempts yet	2s	128 MB	Judgeable
Remarkable StudentsGiven three permutations representing exam ranks of N students, count students not dominated by any other student in all three ranks.	Medium6	SortingDivide and conquer+2	No attempts yet	2s	192 MB	Judgeable
Mirror RaysSimulate light rays reflecting off '/' mirrors in an N×M grid and report, for each numbered border hole, which hole the ray exits from.	Medium6	SimulationMatrix+1	No attempts yet	2s	256 MB	Judgeable
Mine RemovalGiven a grid with buildings, walls, and empty cells, choose bomb placements of a fixed blast radius so every empty cell is blasted without any blast touching a building.	Medium6	SimulationGreedy+1	No attempts yet	2s	128 MB	Judgeable
Wireless Communication Base StationsAssign positive integer frequencies to at most 12 base stations so adjacent stations (within distance 20) differ by at least 2, minimizing the count of distinct frequencies used.	Medium6	BacktrackingGraph+1	No attempts yet	2s	128 MB	Judgeable
Grand CanalGiven a graph with edge widths, use maximum-spanning-tree logic to answer K queries for the widest ship that can travel between two given cities.	Medium6	Union-findMinimum spanning tree+1	No attempts yet	1s	128 MB	Judgeable
Unknown PolygonReconstruct the boundary cycle of a triangulated (or diagonal-split) convex N-gon from its unordered edge and diagonal list, starting at label 1 with the smaller second label chosen.	Medium6	GraphDFS+1	No attempts yet	2s	128 MB	Judgeable
Keyboard TypoSimulate 2-beolsik Korean keyboard input composition rules to find the position of the first character that breaks valid syllable formation.	Medium6	SimulationImplementation+1	No attempts yet	2s	128 MB	Judgeable
PartyGiven N cooks each able to bring at most K dishes from foods they know how to cook and per-food capacity limits, compute the maximum total dishes preparable via max flow.	Medium6	GraphGreedy+1	No attempts yet	2s	128 MB	Judgeable
Mayor Election PostersGiven n posters pasted in order over intervals on a huge wall, count how many posters remain at least partially visible after later posters overlap earlier ones.	Medium6	Segment treeCombinatorics+2	No attempts yet	1s	192 MB	Judgeable
Fibonacci GameDetermine the smallest first move in a Fibonacci-Nim-like bead-taking game that guarantees a forced win, or -1 if none exists.	Medium6	Game theoryNumber theory+1	No attempts yet	2s	128 MB	Judgeable