Problems

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Total results29,414 problems

Valya and Letter
Medium6
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
How to Fail at Programming Contest
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Berland Railroads
Medium6
Greedy, Tree+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Difficult Problems
Medium6
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
The Last Battle
Medium6
Array, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pizza
Medium6
Bit manipulation, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cute Common Divisor
Medium6
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Robot
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Conquest
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Game
Medium6
Greedy, Game theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
GCD and LCM
Medium6
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sequence Transformation
Medium6
Array, Sliding window+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bank
Medium6
Simulation, Heap+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Minimal Product
Medium6
Implementation, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Two Prefixes
Medium6
String, String matching+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Berland University
Medium6
Binary search, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Tourism
Medium6
String, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Puzzle
Medium6
Combinatorics, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Delivering Problem Sheets
Medium6
Math, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Alchemist
Medium6
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Site Planning
Medium6
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Page Number
Medium6
String, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Tower of Pisa
Medium6
Dynamic programming, Recursion+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Currency Exchange
Medium6
Array, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Robot
Medium6
Prefix sum, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Expedition
Medium6
Graph, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Arranging Shoes
Medium6
Greedy, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Broken Line 01
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
Broken Line 02
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
Broken Line 10
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
Pizza Oven
Medium6
Greedy, Math+2
No attempts yet
Time limit
0.25s
Memory limit
256 MB
Judgeable
Substring
Medium6
String matching, Binary search+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cafe
Medium6
Greedy, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Homework
Medium6
Graph, Topological sort+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Station <<Sorting>>
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Wikipedia
Medium6
String, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Golden Coins
Medium6
Graph, DFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tug of War
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Foreign Passport
Medium6
Graph, BFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Virus
Medium6
BFS, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sudoku (Hard)
Medium6
Backtracking, Implementation+2
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
I Hate Change
Medium6
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Boss Monster Loot
Medium6
BFS, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Delivering Rice Cakes
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Let's Kill the Monster!
Medium6
Brute force, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Wicked Lord Hyeyu
Medium6
Minimum spanning tree, Graph+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Advertising Billboard
Medium6
Union-find, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Afforestation
Medium6
Simulation, BFS
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Vampire Numbers
Medium6
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Square, Not Rectangle
Medium6
Stack, Array+2
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Moving 5
Medium6
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Ball Alignment
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hotspots
Medium6
Dynamic programming, Math
No attempts yet
Time limit
2.5s
Memory limit
512 MB
Judgeable
Road Reconstruction
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Paint
Medium6
Union-find, Graph
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Parenthesis String ?
Medium6
Stack, Prefix sum+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Robot on a Conveyor Belt
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Wizard Shark and Firestorm
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mechanical Doll
Medium6
Implementation, Tree+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mini Tetris
Medium6
Simulation, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Paint By Numbers
Medium6
Dynamic programming, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sudoku 3
Medium6
Backtracking, Matrix+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cave
Medium6
Binary search, Implementation
No attempts yet
Time limit
2s
Memory limit
32 MB
Judgeable
The Hobanwoo Merchant's Strange Quality Calculation
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Hobanwoo and the Rhythm Game
Medium6
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Parity Constraint Shortest Path
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Yonsei Mask Factory
Medium6
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Vista 3
Medium6
Geometry, Sorting+1
No attempts yet
Time limit
0.1s
Memory limit
128 MB
Judgeable
Vista 4
Medium6
Geometry, Sorting
No attempts yet
Time limit
0.1s
Memory limit
128 MB
Judgeable
Vista 5
Medium6
Geometry, Sorting+1
No attempts yet
Time limit
0.1s
Memory limit
128 MB
Judgeable
Fired Runner on the Construction Site
Medium6
Shortest path, BFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stop Right There. Are You Dealing Off the Bottom?
Medium6
Array, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Odd Number Holic Hoseok
Medium6
Dynamic programming, Recursion+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Autonomous Vehicle
Medium6
Simulation, Geometry+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Electric Vehicle
Medium6
Dynamic programming, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Wiggly Hoseok Caterpillar - Efficiency
Medium6
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Alley Boss Hoseok - Efficiency 2
Medium6
Binary search, Graph+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Paper Folding
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Bajka
Medium6
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Papričice
Medium6
Tree, DFS+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Svjetlo
Medium6
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Why Puang Crossed the Road
Medium6
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Calendar
Medium6
Implementation, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Jinwoo's Mint Chocolate Milk
Medium6
Backtracking, BFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Straight Switch Game
Medium6
BFS, Graph+2
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Binary Seating
Medium6
Probability, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Kangaroo Commotion
Medium6
BFS, Bit manipulation+1
No attempts yet
Time limit
7s
Memory limit
512 MB
Judgeable
Folding
Medium6
Geometry, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Last Will
Medium6
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Garden
Medium6
Graph, Greedy+2
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
In The Name Of Confusion
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
256 shades of Gray
Medium6
Bit manipulation, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sticker Album
Medium6
Probability, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
SBC Hangar
Medium6
Combinatorics, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Ká entre Nós
Medium6
Graph, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lavaspar
Medium6
Implementation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Multiplied Numbers
Medium6
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Short on Fuel
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pineapple Pizza
Medium6
Array, Two pointers+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sogang Muscle Man
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Valya and LetterGiven a sheet n by m and an envelope h by w, fold the sheet in half along either axis repeatedly so it fits (rotation allowed), minimizing folds.	Medium6	MathGreedy+2	No attempts yet	1s	512 MB	Judgeable
How to Fail at Programming ContestGennady picks the order of problems he solves, never starting one he cannot finish, to minimize total points scored within T minutes.	Medium6	Dynamic programmingSorting+1	No attempts yet	1s	512 MB	Judgeable
Berland RailroadsGiven the required railroad count d_i for each of n cities, build a connected tree with exactly those degrees that minimizes the maximum number of train changes.	Medium6	GreedyTree+1	No attempts yet	1s	512 MB	Judgeable
Difficult ProblemsGiven a string of lowercase letters and 'A's, split the 'A's into the maximum number of groups with distinct positive sizes, allowing lowercase letters between groups.	Medium6	GreedyMath+2	No attempts yet	1s	512 MB	Judgeable
The Last BattleA permutation a is fixed; rotating the identity arrangement right by k positions must satisfy a[i] != shifted value at each position. Find the smallest valid k, or -1.	Medium6	ArrayMath+2	No attempts yet	1s	512 MB	Judgeable
PizzaCount the ways to choose which of n optional ingredients go on a pizza so that every one of up to 20 friends has at least one wish met, modulo 998244353.	Medium6	Bit manipulationCombinatorics+1	No attempts yet	2s	512 MB	Judgeable
Cute Common DivisorGiven a and b up to 1e9, find a common divisor d whose digit sum is as large as possible, and print any such divisor.	Medium6	Number theoryMath+2	No attempts yet	2s	512 MB	Judgeable
RobotGiven a sequence of signed step sizes, flip at most k signs to maximize the absolute value of the final position.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
ConquestFind the minimum coins to pay so every warrior joins, where a city's remaining warriors join free once the army has more than that city's remaining count.	Medium6	Dynamic programmingGreedy+1	No attempts yet	2s	512 MB	Judgeable
GameTwo players alternately claim columns they can reach; each wants to claim more columns than the other, and the winner under optimal play is reported.	Medium6	GreedyGame theory+2	No attempts yet	2s	512 MB	Judgeable
GCD and LCMGiven a and b, find positive x <= y with the same gcd and lcm as a and b, minimizing y - x.	Medium6	Number theoryMath+2	No attempts yet	2s	512 MB	Judgeable
Sequence TransformationGiven a sequence of non-negative integers, find the minimum number of single increments needed so that 1,2,...,h appear consecutively as a block, or report that it is impossible.	Medium6	ArraySliding window+2	No attempts yet	2s	512 MB	Judgeable
BankGiven n dwarves with arrival times, employee service times, and accountant times, simulate a shared employee queue of m servers and a single accountant to find each dwarf's departure time.	Medium6	SimulationHeap+2	No attempts yet	2s	512 MB	Judgeable
Minimal ProductGenerate a pseudorandom array and find indices i<j with a_i<a_j minimizing the product a_i*a_j, or report IMPOSSIBLE.	Medium6	ImplementationGreedy+2	No attempts yet	2s	512 MB	Judgeable
Two PrefixesGiven strings s and t, count distinct strings formed by concatenating a non-empty prefix of s with a non-empty prefix of t.	Medium6	StringString matching+2	No attempts yet	1s	512 MB	Judgeable
Berland UniversityGiven t students, n lectures alternating between two auditoriums of sizes a and b, and a passing threshold k, find the maximum number of students who can each attend at least k lectures.	Medium6	Binary searchGreedy+2	No attempts yet	1s	512 MB	Judgeable
TourismGiven a 0/1 string, find two different segments with the same length and the same number of 1s, where that length is as large as possible.	Medium6	StringPrefix sum+1	No attempts yet	1s	512 MB	Judgeable
PuzzleCount rotation-distinct square puzzle pieces whose sides are each smooth, one of k tabs, or one of k blanks, classified into corners, borders, and normals.	Medium6	CombinatoricsMath+2	No attempts yet	1s	512 MB	Judgeable
Delivering Problem SheetsGiven N points and Q query points in 11 dimensions, report for each query the maximum Manhattan distance to any of the N points.	Medium6	MathBit manipulation+2	No attempts yet	2s	1024 MB	Judgeable
AlchemistGiven counts of minerals valued 0 to N-1, find the largest value of the single mineral left after repeatedly combining minerals into their MEX.	Medium6	GreedyMath+1	No attempts yet	1s	1024 MB	Judgeable
Site PlanningCount quadruples of positive integers (a,b,c,d) with ab - cd = n, a>c, b>d, and a,b both different from x.	Medium6	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Page NumberGiven a digit string, count the ways to split it into two positive integers i and n with no leading zeros, representing "Page i of n".	Medium6	StringImplementation+2	No attempts yet	2s	512 MB	Judgeable
The Tower of PisaGiven n disks stacked on the first of three rods, where the second rod lets you move a group of top disks together, find the minimum moves to shift all disks to the third rod.	Medium6	Dynamic programmingRecursion+1	No attempts yet	2s	512 MB	Judgeable
Currency ExchangeGiven n tablet values and an integer rate p, find two distinct indices i and j so that the ratio c_i / c_j is as close to p as possible.	Medium6	ArrayBinary search+2	No attempts yet	2s	512 MB	Judgeable
RobotCount the subroutines (l, r) of a robot program on an n by n rock field that never leave the field or step onto a rock.	Medium6	Prefix sumHash map+1	No attempts yet	2s	512 MB	Judgeable
ExpeditionEach candidate forbids at most one other candidate; choose the largest subset where no included candidate's forbidden partner is also included.	Medium6	GraphGreedy+2	No attempts yet	2s	512 MB	Judgeable
Arranging ShoesGiven 2n shoes in a row, each size appearing as a left and right shoe, find the fewest adjacent swaps needed to make every pair sit as left then right.	Medium6	GreedyArray+1	No attempts yet	1s	1024 MB	Judgeable
Broken Line 01Given dots with distinct x and y coordinates, construct a horizontal/vertical broken line from the origin that passes through every dot, minimizing segments for partial score.	Medium6	GreedySorting+2	No attempts yet	0.1s	512 MB	Judgeable
Broken Line 02Construct a rectilinear broken line from the origin that passes through every given dot, minimizing the number of segments; scored by segment count.	Medium6	SortingGreedy+2	No attempts yet	0.1s	512 MB	Judgeable
Broken Line 10Given n points with distinct x and y, output a rectilinear broken line from the origin that passes through every point, using few segments.	Medium6	SortingGreedy+2	No attempts yet	0.1s	512 MB	Judgeable
Pizza OvenFind the fewest button presses (ADDH, ADDT, MINT, ADDO, MINO) to reach a target time, breaking ties by lexicographically smallest press counts.	Medium6	GreedyMath+2	No attempts yet	0.25s	256 MB	Judgeable
SubstringGiven string s and n queries (l, r, t), for each one check whether t occurs as a substring of s from position l to r.	Medium6	String matchingBinary search+1	No attempts yet	2s	512 MB	Judgeable
CafePlace exactly k chairs in an n by m grid so every chair touches at least one table in its 8 neighbors, or report impossibility.	Medium6	GreedyImplementation+2	No attempts yet	2s	512 MB	Judgeable
HomeworkGiven a DAG of assignments with durations, remove one vertex to minimize the makespan of the remaining precedence-constrained schedule.	Medium6	GraphTopological sort+2	No attempts yet	2s	512 MB	Judgeable
Station <<Sorting>>Given n distinct masses in a row, you may swap two adjacent cars only when their total mass is at most M; decide whether sorting by increasing mass is reachable.	Medium6	SortingGreedy+2	No attempts yet	2s	512 MB	Judgeable
WikipediaGiven n articles with title synonyms and text, wrap every word matching another article's title or synonym in a wiki link, using short form for exact title matches and full form otherwise.	Medium6	StringHash map+1	No attempts yet	2s	512 MB	Judgeable
Golden CoinsGiven coin counts on the roads of a 3x4 grid, find the most coins Thomas can collect when each crossing takes the rounded-up half of a road's coins.	Medium6	GraphDFS+1	No attempts yet	2s	512 MB	Judgeable
Tug of WarGiven n rope pieces, joining two pieces consumes d from each end and adjacent knots must be at least d apart; maximize the total length of one resulting rope.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Foreign PassportFind the shortest walk on a grid from the start cell that enters Bureau Confederation cells exactly n times, and print the moves as N, E, S, W.	Medium6	GraphBFS+1	No attempts yet	2s	512 MB	Judgeable
VirusCount the distinct infected configurations possible after t seconds of spread from at most 8 starting cells on an n by m grid.	Medium6	BFSHash map+1	No attempts yet	2s	512 MB	Judgeable
Sudoku (Hard)Fill a 9x9 Sudoku grid so every row, column, and 3x3 box holds the digits 1 to 9 exactly once.	Medium6	BacktrackingImplementation+2	No attempts yet	0.1s	512 MB	Judgeable
I Hate ChangeGiven N fractions, find the largest fraction that divides every given fraction exactly, with the answer reduced to lowest terms.	Medium6	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
Boss Monster LootGiven a grid with up to 26 players and a boss, compute how many players can land a hit before the boss dies from cumulative damage.	Medium6	BFSGreedy+2	No attempts yet	1s	256 MB	Judgeable
Delivering Rice CakesGiven a weighted graph, a start house Y, and a daily walking limit X, find how many days it takes to visit every other house if each day's trip must return to Y and stay within X.	Medium6	GraphShortest path+2	No attempts yet	1s	512 MB	Judgeable
Let's Kill the Monster!Each skill takes 1 second to cast, then deals its damage; after casting you must wait out its cooldown. Find the earliest time the monster's HP reaches zero.	Medium6	Brute forceSimulation+2	No attempts yet	2s	512 MB	Judgeable
Wicked Lord HyeyuBuild a minimum spanning tree over N villages with K weighted edges, then report the largest shortest-path distance between any two villages in that tree.	Medium6	Minimum spanning treeGraph+2	No attempts yet	0.5s	512 MB	Judgeable
Advertising BillboardGiven k on/off patterns for an n by m grid of bulbs, partition the bulbs into the fewest groups so that within each pattern every group is uniformly on or uniformly off.	Medium6	Union-findImplementation+2	No attempts yet	2s	512 MB	Judgeable
AfforestationGiven an n by m grid of tree heights, find how many years pass until no two adjacent trees differ by exactly 1, and print each tree's final height.	Medium6	SimulationBFS	No attempts yet	2s	512 MB	Judgeable
Vampire NumbersGiven k and n, the task is to print k distinct n-digit vampire numbers, each written with its two n/2-digit fangs.	Medium6	MathImplementation	No attempts yet	2s	512 MB	Judgeable
Square, Not RectangleGiven bar heights of a histogram with unit widths, find the side length of the largest axis-aligned square that fits inside it.	Medium6	StackArray+2	No attempts yet	1.5s	1024 MB	Judgeable
Moving 5Find the maximum candy sum along a monotone path from (1,1) to (N,M) in an N by M grid where room (i,j) holds A_i*10^9 + B_j.	Medium6	GreedyMath+1	No attempts yet	1s	512 MB	Judgeable
Ball AlignmentGiven n numbered balls on a curved track, find the fewest balls to move to the far left or far right so the numbers end up in non-decreasing order.	Medium6	Dynamic programmingSorting+1	No attempts yet	1s	512 MB	Judgeable
HotspotsGiven n AP positions on a line, choose non-overlapping hotspot radii that maximize the sum of the squared radii.	Medium6	Dynamic programmingMath	No attempts yet	2.5s	512 MB	Judgeable
Road ReconstructionGiven a grid where cells cost 0, 1, or 2 to cross and -1 is blocked, find the minimum total construction cost of a path from the top-left to the bottom-right cell.	Medium6	GraphShortest path+2	No attempts yet	1s	512 MB	Judgeable
PaintApply Q bucket-fill operations in order to an R by S pixel grid and print the final colors of every pixel.	Medium6	Union-findGraph	No attempts yet	3s	512 MB	Judgeable
Parenthesis String ?Given a parenthesis string and range queries, output the sum over all queries of 1 if the queried substring is a correct parenthesis string, else 0.	Medium6	StackPrefix sum+2	No attempts yet	0.5s	512 MB	Judgeable
Robot on a Conveyor BeltSimulate a rotating conveyor belt where robots load, advance when possible, and stop once K cells have zero durability, reporting the step count.	Medium6	SimulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
Wizard Shark and FirestormRepeat Q times: rotate every 2^L x 2^L block 90 degrees clockwise, then subtract 1 from each ice cell that has fewer than 3 ice neighbors. Output the total ice and the largest connected ice chunk.	Medium6	ImplementationSimulation+2	No attempts yet	1s	512 MB	Judgeable
Mechanical DollBuild a circuit of origin, trigger, and switch devices so the ball enters triggers in the order A, then returns to the origin with every switch back in state X.	Medium6	ImplementationTree+1	No attempts yet	1s	512 MB	Judgeable
Mini TetrisChoose the position and rotation of each of the three figure types as it falls so that five non-empty lines never build up before n figures land.	Medium6	SimulationDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
Paint By NumbersGiven a row of n cells, clue block lengths, and some fixed cells, find which cells are black or white in every valid painting.	Medium6	Dynamic programmingString+1	No attempts yet	2s	512 MB	Judgeable
Sudoku 3Fill the empty cells of an n^2 by n^2 Sudoku board with values from 1 to n^2 so that rows, columns, and sub-grids stay distinct, filling as many cells as possible.	Medium6	BacktrackingMatrix+1	No attempts yet	1s	512 MB	Judgeable
CaveFind each switch's connected door and correct up/down position using at most 70,000 queries that report the first closed door.	Medium6	Binary searchImplementation	No attempts yet	2s	32 MB	Judgeable
The Hobanwoo Merchant's Strange Quality CalculationPartition N quality values into subsets, where each subset contributes its upper median times its size, and maximize the total.	Medium6	GreedySorting+2	No attempts yet	1s	256 MB	Judgeable
Hobanwoo and the Rhythm GameGiven note scores, choose which notes to miss so that no three consecutive notes are missed, maximizing the sum of combo times score over the notes that are hit.	Medium6	Dynamic programmingArray+2	No attempts yet	1s	256 MB	Judgeable
Parity Constraint Shortest PathGiven an undirected weighted graph, find for every vertex the minimum cost of an even path and of an odd path from vertex 1, allowing repeated vertices and edges.	Medium6	GraphShortest path+2	No attempts yet	1s	1024 MB	Judgeable
Yonsei Mask FactoryAssign each one-way passage a flow between its minimum s_i and maximum e_i so every site's net flow matches p_i, or report that it is impossible.	Medium6	GraphBFS+1	No attempts yet	1s	1024 MB	Judgeable
Vista 3Given up to 1,000,000 points in the plane, output a closed tour that visits every point exactly once and returns to the starting point.	Medium6	GeometrySorting+1	No attempts yet	0.1s	128 MB	Judgeable
Vista 4Given up to 1,000,000 points in the plane, find a closed route that visits every point once and returns to the start, as short as possible.	Medium6	GeometrySorting	No attempts yet	0.1s	128 MB	Judgeable
Vista 5Find a closed route through up to 1,000,000 points on a plane that visits each once and returns to the start, with a short total Euclidean length.	Medium6	GeometrySorting+1	No attempts yet	0.1s	128 MB	Judgeable
Fired Runner on the Construction SiteFind the earliest time to reach the bottom-right cell, where each cell must be entered before its deadline and straight runs speed up.	Medium6	Shortest pathBFS+1	No attempts yet	1s	1024 MB	Judgeable
Stop Right There. Are You Dealing Off the Bottom?Given an even deck of cards dealt alternately from the top, find the maximum total sum Jeonghun can collect if he may deal one card from the bottom instead.	Medium6	ArrayDynamic programming+2	No attempts yet	2s	1024 MB	Judgeable
Odd Number Holic HoseokSplit a number repeatedly into 2 or 3 parts, summing the parts, and track the total count of odd digits seen; find the minimum and maximum possible totals.	Medium6	Dynamic programmingRecursion+2	No attempts yet	1s	512 MB	Judgeable
Autonomous VehicleGiven horizontal and vertical road segments and a start endpoint, find the vehicle's coordinates at time t when it turns left at intersections and bounces at road ends.	Medium6	SimulationGeometry+1	No attempts yet	1s	512 MB	Judgeable
Electric VehicleFind the cheapest trip from S to T on a complete graph of villages with Manhattan distances, using at most Δ recharges and battery capacity W.	Medium6	Dynamic programmingShortest path+1	No attempts yet	2s	512 MB	Judgeable
Wiggly Hoseok Caterpillar - EfficiencyChoose disjoint consecutive blocks of food, each summing to at least K, to maximize the total sum minus K times the number of blocks.	Medium6	Dynamic programmingPrefix sum+2	No attempts yet	1s	512 MB	Judgeable
Alley Boss Hoseok - Efficiency 2Find the minimum possible maximum edge toll along a path from A to B whose total toll is at most C, or -1 if no path fits the budget.	Medium6	Binary searchGraph+2	No attempts yet	5s	512 MB	Judgeable
Paper FoldingGiven k, a sequence of 2k folds, and one punched corner of the final unit square, print the full grid of hole positions after unfolding.	Medium6	ImplementationSimulation+2	No attempts yet	0.5s	512 MB	Judgeable
BajkaFind the least time to write word t by moving a finger over word s, where adjacent moves write a letter and same-letter jumps write nothing.	Medium6	Dynamic programmingString	No attempts yet	1s	512 MB	Judgeable
PapričiceGiven a tree of n peppers, cut two edges to split it into three components and minimize the gap between the largest and smallest sizes.	Medium6	TreeDFS+1	No attempts yet	1s	512 MB	Judgeable
SvjetloGiven a tree of bulbs with their initial on/off states, find the shortest walk along wires that visits each off bulb an odd number of times and each on bulb an even number of times.	Medium6	TreeDFS+1	No attempts yet	2s	512 MB	Judgeable
Why Puang Crossed the RoadGiven a line Ax+By+C=0 and an axis-aligned rectangle, decide whether the line passes through the rectangle's interior; touching only a corner or edge does not count.	Medium6	GeometryMath+1	No attempts yet	1s	512 MB	Judgeable
CalendarPlace each schedule as high as possible on a 365-day calendar, group horizontally consecutive days into rectangles, and print the total coated area.	Medium6	ImplementationSorting+2	No attempts yet	1s	512 MB	Judgeable
Jinwoo's Mint Chocolate MilkOn an N x N grid with one home, at most ten milk spots, initial stamina M, and stamina gain H per drink, find the most bottles Jinwoo can drink and still return home.	Medium6	BacktrackingBFS+2	No attempts yet	1s	512 MB	Judgeable
Straight Switch GameEach switch adds its own index (mod 5) to the cubes it connects; find the fewest presses that make every cube's value equal, or report -1.	Medium6	BFSGraph+2	No attempts yet	1.5s	512 MB	Judgeable
Binary SeatingEach of n students independently picks room 0 or room 1 with equal probability; compute the expected maximum finish time among the students who pick room 1.	Medium6	ProbabilityDynamic programming+2	No attempts yet	1s	512 MB	Judgeable
Kangaroo CommotionFind the fewest jumps for a kangaroo to visit all k other kangaroos in order, then stop at the safe area, with jump velocity changing by at most 1 per step on a grid.	Medium6	BFSBit manipulation+1	No attempts yet	7s	512 MB	Judgeable
FoldingGiven two disjoint red intervals on a 1e9 long tape, fold at position x and report the total length of the resulting red region, for up to 1e6 queries.	Medium6	GeometryMath+2	No attempts yet	2s	1024 MB	Judgeable
Last WillGiven positive integers p, q, r, decide whether a point X strictly inside the unit square splits the four midpoint quadrilaterals in ratio p:q:r, and if so print X as irreducible fractions.	Medium6	GeometryMath+2	No attempts yet	1s	1024 MB	Judgeable
GardenPlant cacti on a grid so no two adjacent cells both hold one, maximizing the count and printing one valid layout.	Medium6	GraphGreedy+2	No attempts yet	10s	1024 MB	Judgeable
In The Name Of ConfusionGiven n numbers, find the minimum and maximum total edge weight over all spanning trees where an edge between i and j costs a_i * a_j, output modulo 1e9+7.	Medium6	GreedySorting+2	No attempts yet	2s	1024 MB	Judgeable
256 shades of GrayDecode ten hexadecimal grey levels into black or white bits, then invert the standard's Gray-code pattern to recover the measured height.	Medium6	Bit manipulationMath+2	No attempts yet	1s	512 MB	Judgeable
Sticker AlbumEach pack holds a uniformly random integer count of stickers from A to B; find the expected number of packs needed to collect at least N stickers.	Medium6	ProbabilityDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
SBC HangarCount the K-element subsets of N distinct weights whose sum lies in [A, B], given that each weight is at least twice the next smaller one.	Medium6	CombinatoricsSorting+2	No attempts yet	2s	512 MB	Judgeable
Ká entre NósGiven an undirected graph with P vertices and F edges, decide whether the vertices can be split into at most two groups so that every vertex has an odd number of neighbors inside its own group.	Medium6	GraphMath+2	No attempts yet	2s	512 MB	Judgeable
LavasparCount grid cells that belong to at least one contiguous straight segment (row, column, or diagonal) whose letters form an anagram of some word in the given list.	Medium6	ImplementationBrute force+2	No attempts yet	2s	512 MB	Judgeable
Multiplied NumbersGiven a bipartite multigraph and the products c_i of the primes on each N-vertex's neighbors, recover the M ordered primes p_1 < ... < p_M.	Medium6	Number theoryMath+2	No attempts yet	2s	512 MB	Judgeable
Short on FuelGiven fuel depots on a grid, find the minimum starting fuel so a car moving only right or down can reach the goal, refueling at depots it passes.	Medium6	Dynamic programmingSorting+2	No attempts yet	1s	1024 MB	Judgeable
Pineapple PizzaCount starting slices of a circular pizza so that a contiguous block served to guests, ordered by age, has strictly more toppings than every younger guest.	Medium6	ArrayTwo pointers+2	No attempts yet	2s	1024 MB	Judgeable
Sogang Muscle ManPair up N machines into floor(N/2) pairs plus possibly one leftover so the largest pair sum is minimized, and report that smallest possible maximum.	Medium6	GreedySorting+2	No attempts yet	1s	1024 MB	Judgeable