Problems

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Total results29,425 problems

Villain Robots
Medium6
Dynamic programming, String matching+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Roadblock
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Umbrellas for Cows
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Above the Median
Medium6
Prefix sum, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Lineup
Medium6
Sorting, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Visiting Cows
Medium6
Tree, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Chocolate Milk
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Apple Delivery
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Treasure Chest
Medium6
Dynamic programming, Game theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Trough Game
Medium6
Brute force, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dividing the Gold
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lucky Charms
Medium6
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mowing the Lawn
Medium6
Dynamic programming, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Learning Languages
Medium6
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Claustrophobic Cows
Medium6
Geometry, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dizzy Cows
Medium6
Graph, Topological sort+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Video Game Troubles
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Great Cow Gathering
Medium6
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Driving Out the Piggies
Medium6
Probability, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Time Travel
Medium6
Stack, Tree+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mixed Up Cows
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Kaing Calendar
Medium6
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Buying Hay
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Chocolate
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Trick or Treat on the Farm
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Secret Message
Medium6
Trie, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Laser Communication
Medium6
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Competition
Medium6
Math, Hash map+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Bulls and Cows
Medium6
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Frisbee Team
Medium6
Dynamic programming, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Watering Plan Check 3
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Work Scheduling
Medium6
Greedy, Heap+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cake
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Super Paintball
Medium6
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Hurdles
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Milking Time
Medium6
Dynamic programming, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gourmet Grazers
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cell Phone Network
Medium6
Tree, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Meteor Shower
Medium6
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
River Crossing
Medium6
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Cars
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Building the Moat
Medium6
Geometry, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Roadblocks
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Big Square
Medium6
Geometry, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Round Numbers
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
New Cow Brands
Medium6
Backtracking, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Roller Coaster
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Standing Long Jump
Medium6
Binary search, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Balanced Lineup
Medium6
Segment tree, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Protecting the Flowers
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ranking the Cows
Medium6
Graph, Topological sort+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Face the Right Way
Medium6
Greedy, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Traffic
Medium6
Graph, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cheapest Palindrome
Medium6
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Widening of Channels
Medium6
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Leaking Dike
Medium6
Array, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Computerizing a Stockroom
Medium6
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Party at Hali-Bula
Medium6
Tree, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Treasure of Chimp Island
Medium6
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Xavier Is Learning to Count
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Universal Question Answering System
Medium6
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Reflections
Medium6
Geometry, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Going in Circles on Alpha Centauri
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Triangles
Medium6
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Instant Complexity
Medium6
Implementation, Stack+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Always on the run
Medium6
Dynamic programming, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Island of Logic
Medium6
Brute force, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Railroad
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Robbery
Medium6
Dynamic programming, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Game
Medium6
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dividing
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
King
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Crossword Diagrams
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Network
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Plato's Blocks
Medium6
Backtracking, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Round and Round We Go
Medium6
String, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Well-Formed Problem
Medium6
String, Stack+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Code Breaking
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hearts
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bonus Bonds
Medium6
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Laser Lines
Medium6
Geometry, Hash map+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Network Wars
Medium6
Graph, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Strategy
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Paper Folding
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shuffling Patience
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Car Trialling
Medium6
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Equivalent Resistance of a Resistor Network
Medium6
Graph, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Domino Effect
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Intersection
Medium6
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Synchronous Design
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Anagram
Medium6
Backtracking, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Spreadsheet
Medium6
Graph, Topological sort+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Alien Security
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Trip Routing
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pascal Program Lengths
Medium6
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pizza Anyone?
Medium6
Bit manipulation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
PostScript Printer Driver
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Finite State Text-Processing Machine
Medium6
Simulation, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
PostScript Emulation
Medium6
Simulation, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Annoying Painting Tool
Medium6
Greedy, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Villain RobotsChoose a string of K characters over {A,B,C} maximizing the total number of substring occurrences of the given pattern strings.	Medium6	Dynamic programmingString matching+2	No attempts yet	1s	128 MB	Judgeable
RoadblockGiven a weighted undirected graph, double the length of one edge to maximize the increase in the shortest path from field 1 to field N.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Umbrellas for CowsGiven cow positions on a line and a price for each umbrella width, find the cheapest set of umbrellas that covers every cow, allowing overlaps.	Medium6	Dynamic programmingSorting+2	No attempts yet	1s	128 MB	Judgeable
Above the MedianGiven N cow heights, count contiguous ranges whose defined median (the ceil(K/2)-th smallest) is at least a threshold X.	Medium6	Prefix sumBinary search+2	No attempts yet	1s	128 MB	Judgeable
Cow LineupFind the minimum span of x coordinates covering at least one cow of every distinct breed id.	Medium6	SortingSliding window+2	No attempts yet	1s	128 MB	Judgeable
Visiting CowsGiven a tree with N vertices, choose the largest set of vertices with no two adjacent, which is the maximum independent set on a tree.	Medium6	TreeDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Chocolate MilkGiven a directed tree with N-1 edges where all flow reaches one sink, list every non-source node that lies on every root-to-sink path.	Medium6	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Apple DeliveryGiven a weighted undirected graph, find the shortest round trip from a start node that visits two given nodes in either order.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Treasure ChestTwo players alternately take a coin from either end of a row of N coins; find the maximum total the first player can guarantee with optimal play.	Medium6	Dynamic programmingGame theory+2	No attempts yet	1s	128 MB	Judgeable
The Trough GameGiven N troughs and M queries that each count filled troughs within a listed subset, find the filled set or report impossible or non-unique.	Medium6	Brute forceBit manipulation+1	No attempts yet	1s	128 MB	Judgeable
Dividing the GoldGiven N coins with values, find the minimum difference between two piles and count the subsets forming the lighter pile, modulo 1,000,000.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Lucky CharmsGiven a bracelet of length L nailed at position N, with charms at positions P_i hanging on strings of length S_i, compute how far below the nail each charm droops.	Medium6	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
Mowing the LawnGiven N cows in a row with efficiencies, pick a subset that never includes more than K adjacent cows and maximize the total efficiency.	Medium6	Dynamic programmingSliding window+2	No attempts yet	1s	128 MB	Judgeable
Learning LanguagesGiven which languages each cow speaks, find how many extra language lessons are needed so that every pair of cows is connected through shared languages.	Medium6	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Claustrophobic CowsGiven up to 2000 points, find the unique pair with the smallest Euclidean distance and print their ids in increasing order.	Medium6	GeometryDivide and conquer+2	No attempts yet	1s	128 MB	Judgeable
Dizzy CowsDirect each two-way edge using the lexicographically smallest topological order of the given acyclic one-way edges, or report -1 if a cycle exists.	Medium6	GraphTopological sort+2	No attempts yet	1s	128 MB	Judgeable
Video Game TroublesGroup knapsack: buy at most one of each console, and only games whose console is already bought, maximizing total production value within budget V.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Great Cow GatheringPick a node of a weighted tree with node weights as the gathering point, and minimize the sum of cow count times distance to that node.	Medium6	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
Driving Out the PiggiesA bomb starts at city 1 of an undirected graph, detonates at each visit with probability P/Q and otherwise moves to a random neighbor; find the detonation probability for every city.	Medium6	ProbabilityGraph+2	No attempts yet	1s	128 MB	Judgeable
Time TravelProcess add, pop, and rewind-to-earlier-query operations on a recorded list, printing the last element after each query.	Medium6	StackTree+2	No attempts yet	1s	128 MB	Judgeable
Mixed Up CowsCount permutations of N serial numbers (N at most 16) where every adjacent pair differs by more than K.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Kaing CalendarGiven cycle lengths M and N, find the smallest k with k mod M = x and k mod N = y, the CRT problem, or report -1.	Medium6	MathNumber theory+2	No attempts yet	1s	256 MB	Judgeable
Buying HayGiven N package types with unlimited supply, each weighing P_i and costing C_i, find the minimum total cost to buy at least H pounds of hay.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
ChocolateFor C equally likely colors, after N draws where matching pairs are eaten, find the probability that exactly M colors remain on the table.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Trick or Treat on the FarmEach stall has one outgoing next pointer. For every starting stall, count how many distinct stalls the walk visits before it first revisits a stall.	Medium6	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Secret MessageGiven M binary messages and N binary codewords, count for each codeword how many messages share a prefix relation with it in either direction.	Medium6	TrieString+2	No attempts yet	1s	128 MB	Judgeable
Laser CommunicationOn a grid with walls and two C cells, find the fewest mirrors (/ or \) needed so a laser fired from one C reaches the other.	Medium6	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
CompetitionEach runner's lap times grow by 1 ms per lap but reset every p_i laps; find the maximum number of runners who cross the start line at the same millisecond.	Medium6	MathHash map+2	No attempts yet	3s	128 MB	Judgeable
Bulls and CowsCount binary sequences of length N where every pair of bulls has at least K cows between them, modulo 5000011.	Medium6	Dynamic programmingCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Cow Frisbee TeamCount the nonempty subsets of N cows whose rating sum is divisible by F, modulo 100000000.	Medium6	Dynamic programmingMath+2	No attempts yet	1s	128 MB	Judgeable
Watering Plan Check 3Given a grid land divided into fields and a proposed sprinkler plan drawn with letters and underscores, verify the plan and count holes drilled in fences.	Medium6	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Work SchedulingGiven jobs each taking one unit of time with a deadline and a profit, choose a subset to schedule so total profit is maximized.	Medium6	GreedyHeap+2	No attempts yet	1s	128 MB	Judgeable
CakePartition the sequence of slice lengths into consecutive blocks, bottom to top, so each block's sum is at least the one above, and maximize the number of blocks.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Super PaintballGiven up to 100000 opponent positions on an N by N grid, count cells from which a shot along its row, column, or either diagonal would pass through every opponent.	Medium6	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
Cow HurdlesFor each of many queries, find the route between two stations that minimizes the tallest hurdle, or report -1 if unreachable.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Milking TimeChoose non-overlapping milking intervals, each separated by at least R rest hours, to maximize the total milk produced over N hours.	Medium6	Dynamic programmingBinary search+2	No attempts yet	1s	128 MB	Judgeable
Gourmet GrazersAssign each cow a distinct grass type whose price and greenness both meet her minimums, minimizing total price; print -1 if impossible.	Medium6	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Cell Phone NetworkGiven a tree of N pastures, choose the fewest vertices so that every vertex is chosen or adjacent to a chosen one.	Medium6	TreeDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Meteor ShowerFind the earliest time for a unit-speed mover to reach any lattice point that no meteor ever destroys, given each meteor's impact time and cross-shaped destruction.	Medium6	BFSGraph+1	No attempts yet	1s	128 MB	Judgeable
River CrossingSplit N cows into consecutive groups, each crossing costs M plus the cumulative marginal cost, and add M for every return trip; minimize the total time.	Medium6	Dynamic programmingPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Cow CarsAssign cows to M lanes so each cow's speed minus D times the number of cows ahead in its lane stays at least L, maximizing the number of cows used.	Medium6	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Building the MoatGiven N distinct points with no three collinear, compute the perimeter of their convex hull and print it to two decimal places.	Medium6	GeometrySorting+2	No attempts yet	1s	128 MB	Judgeable
RoadblocksFind the length of the second-shortest walk from vertex 1 to vertex N in an undirected weighted graph, where walks may repeat edges.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Big SquarePlace one extra 'J' on an empty cell of an N by N grid so that the four corners of some 'J' square have the largest possible area.	Medium6	GeometryBrute force+2	No attempts yet	1s	128 MB	Judgeable
Round NumbersCount integers in [Start, Finish] whose binary form has at least as many zeroes as ones.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
New Cow BrandsGiven each position's allowed distinct letters, list the codes ranked from start to finish in lexicographic order, where no letter repeats inside a code.	Medium6	BacktrackingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Cow Roller CoasterChoose components that tile [0, L] with no gaps or overlaps, maximizing total fun while keeping total cost within budget B.	Medium6	Dynamic programmingSorting+2	No attempts yet	1s	128 MB	Judgeable
Standing Long JumpRemove exactly m of n interior stones so the smallest gap between consecutive stepping points from 0 to d is as large as possible.	Medium6	Binary searchGreedy+2	No attempts yet	1s	128 MB	Judgeable
Balanced LineupGiven N cow heights and Q ranges, report the difference between the maximum and minimum height within each query range.	Medium6	Segment treeArray+2	No attempts yet	1s	128 MB	Judgeable
Protecting the FlowersFind the order to carry cows to their barns so the total number of flowers trampled while any cow waits is minimized.	Medium6	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Ranking the CowsGiven partial comparison results between N cows with distinct milk rates, find the minimum number of additional pairwise comparisons needed to determine the full ranking.	Medium6	GraphTopological sort+2	No attempts yet	1s	128 MB	Judgeable
Face the Right WayChoose a fixed block size K so that flipping blocks of K consecutive cows turns the whole row forward using the fewest operations, breaking ties by smallest K.	Medium6	GreedySimulation+2	No attempts yet	1s	128 MB	Judgeable
Cow TrafficIn a DAG where every edge goes from a lower to a higher numbered node, count how many source-to-barn paths cross each edge and output the maximum.	Medium6	GraphDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Cheapest PalindromeGiven a string and per-letter insertion and deletion costs, find the minimum cost to turn it into a palindrome by adding or removing characters anywhere.	Medium6	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable
Widening of ChannelsGiven a weighted undirected graph, find the minimum number of edges to widen to width k so that every pair of vertices is connected.	Medium6	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Leaking DikeGiven building heights in a row, water pours over a dike on the left at 1 square meter per minute; find how long until a given building's roof sits 1 meter under water.	Medium6	ArraySimulation+2	No attempts yet	1s	128 MB	Judgeable
Computerizing a StockroomParse handwritten stockroom transactions in chronological order, track computers and part inventories, then print owner and stock summaries sorted by a custom phrase order.	Medium6	ImplementationString+2	No attempts yet	1s	128 MB	Judgeable
Party at Hali-BulaGiven a company hierarchy tree, find the largest set of employees with no boss and employee both chosen, and report whether that maximum set is unique.	Medium6	TreeDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Treasure of Chimp IslandBob enters a grid maze through any boundary gate, may grab at most one dynamite pack, and must find the minimum total stone hardness he has to break to reach the treasure.	Medium6	Shortest pathGraph+2	No attempts yet	1s	128 MB	Judgeable
Xavier Is Learning to CountGiven m distinct positive integers and a size p (at most 5), count for every attainable sum the number of p-element subsets that add up to it, listing sums in increasing order.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	5s	512 MB	Judgeable
Universal Question Answering SystemRead statements of four implication forms, then answer yes/no whether each queried fact follows by chaining the rules.	Medium6	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
ReflectionsGiven disjoint 2D mirror spheres and a ray, trace up to ten reflections and report which spheres the ray hits.	Medium6	GeometrySimulation+2	No attempts yet	1s	128 MB	Judgeable
Going in Circles on Alpha CentauriSimulate transrobs moving clockwise on a ring, assigning requests by age and proximity, then report average wait time and transrob utilization.	Medium6	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
TrianglesIn each triangular grid of white and black cells, find the area of the largest all-white triangle, which may point up or down.	Medium6	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
Instant ComplexityParse a small nested-loop program, compute its running time as a polynomial in n, and print the collected polynomial from highest degree down.	Medium6	ImplementationStack+2	No attempts yet	1s	128 MB	Judgeable
Always on the runFind the cheapest sequence of exactly k daily flights from city 1 to city n, where each ordered pair has a periodic price schedule over days.	Medium6	Dynamic programmingGraph+2	No attempts yet	1s	128 MB	Judgeable
Island of LogicGiven statements by islanders who always tell the truth, always lie, or lie only at night, deduce every fact forced across all valid assignments.	Medium6	Brute forceSimulation+2	No attempts yet	1s	128 MB	Judgeable
RailroadGiven train schedules with stop times, find the journey from a start city to a destination leaving no earlier than a given time, minimizing arrival time and then maximizing departure.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
RobberyGiven time-stamped rectangular exclusions, find the robber's position at each time step where it is uniquely determined, moving at most one cell per step.	Medium6	Dynamic programmingSimulation+1	No attempts yet	1s	128 MB	Judgeable
The GameFor each pair of pieces on a grid, decide if an orthogonal path can join them without crossing others, and give the minimum number of straight segments.	Medium6	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
DividingGiven counts of marbles worth 1 to 6, decide whether the collection can be split into two sets of equal total value.	Medium6	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
KingGiven weighted inequalities on subarray sums, decide whether some integer sequence satisfies all the bounds; output which phrase tells the answer.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Crossword DiagramsTurn each 0/1 grid into a scaled ASCII crossword diagram, number the white cells, and blank out border-connected black regions.	Medium6	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
NetworkGiven an undirected connected graph, count the articulation points whose removal disconnects some other pair of vertices. Input is line-oriented and ends with 0.	Medium6	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Plato's BlocksGiven three n by n shadow patterns, decide whether one connected solid built from unit cubes can cast all three shadows simultaneously.	Medium6	BacktrackingBrute force+2	No attempts yet	1s	128 MB	Judgeable
Round and Round We GoFor each given number, decide whether every product by 1 through its digit count is a rotation of its digits, keeping leading zeros.	Medium6	StringMath+2	No attempts yet	1s	128 MB	Judgeable
A Well-Formed ProblemParse a series of XML documents and decide whether each one satisfies six well-formedness rules, reporting the verdict per document.	Medium6	StringStack+2	No attempts yet	1s	128 MB	Judgeable
Code BreakingDecide whether some periodic permutation maps plaintext to ciphertext1, find the smallest valid period and permutation, then decrypt ciphertext2 with its inverse.	Medium6	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
HeartsSimulate a simplified Hearts game with fixed strategies and report the heart points won by each of the five players, starting with the dealer.	Medium6	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Bonus BondsGiven the next serial number in a region and a digit position, count how many already-sold serials have each digit 0-9 at that position.	Medium6	MathCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Laser LinesFor each coordinate set, find every straight line through three or more points and print the collinear points in sorted order.	Medium6	GeometryHash map+1	No attempts yet	1s	128 MB	Judgeable
Network WarsSimulate two programs moving through a labeled graph, one searching alphabetically forward and one backward, until one is trapped or destroyed.	Medium6	GraphSimulation+2	No attempts yet	1s	128 MB	Judgeable
StrategyParse a small strategy language, then simulate every pair of up to 10 programs for 10 rounds and print each program's total score.	Medium6	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Paper FoldingDraw the dragon curve made by folding a strip of paper N times and opening each crease to 90 degrees, using underscores and bars.	Medium6	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Shuffling PatienceSimulate a solitaire game that covers complementary pairs or JQK triples across up to 16 piles, and report the final pile sizes or the overflow card number.	Medium6	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Car TriallingParse each line against a small case-sensitive grammar and decide whether it is a valid car-trialling instruction, echoing it with spaced collapsed or printing Trap!.	Medium6	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Equivalent Resistance of a Resistor NetworkGiven up to 30 resistors with terminal labels and resistances, compute the equivalent resistance between two points by repeatedly merging series and parallel groups.	Medium6	GraphSimulation+2	No attempts yet	1s	128 MB	Judgeable
Domino EffectDijkstra on a graph of key dominoes; then check each edge for a point where two falling fronts meet, and report the latest finish time and place.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
IntersectionDecide, for each test case, whether a line segment and an axis-aligned rectangle share at least one point, including degenerate rectangles.	Medium6	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
Synchronous DesignGiven a circuit of synchronous and asynchronous nodes with delays, report whether it has an asynchronous cycle, exceeds the clock period between synchronous nodes, or is a valid synchronous design.	Medium6	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
AnagramFor each given word, print every distinct string formed by rearranging its letters, in lexicographic order with duplicates removed.	Medium6	BacktrackingSorting+2	No attempts yet	1s	128 MB	Judgeable
SpreadsheetEach cell holds an integer or a sum formula referring to other cells; evaluate all formulas and print the resulting grid, with no reference cycles.	Medium6	GraphTopological sort+2	No attempts yet	1s	128 MB	Judgeable
Alien SecurityGiven a directed graph with entry at room 0 and a target ET room, find the room closest to the target such that every path from 0 to the target passes through it, excluding the target itself.	Medium6	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Trip RoutingGiven a bidirectional weighted map of city pairs, find and print the shortest route between each queried city pair with full leg-by-leg formatting.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Pascal Program LengthsCount the scored tokens (reserved words, identifiers, constants, parentheses, brackets, and listed operators) in each Turbo Pascal program, skipping comments and strings, and print the member's name with the total.	Medium6	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Pizza Anyone?Each friend accepts a pizza if it meets at least one of their requests; find the fewest-topping pizza, breaking ties by smallest topping string, or report that none exists.	Medium6	Bit manipulationBrute force+2	No attempts yet	1s	128 MB	Judgeable
PostScript Printer DriverSimulate a page renderer that places font C1 and 5x6 asterisk-font C5 strings on a 60x60 grid with left, right, center, and absolute justification, where blanks and dots never overwrite.	Medium6	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
The Finite State Text-Processing MachineSimulate several finite state machines over given input, matching transitions by input sets and printing each transition's output string until END is reached.	Medium6	SimulationGraph+2	No attempts yet	1s	128 MB	Judgeable
PostScript EmulationSimulate a subset of PostScript transforms (rotate, translate, scale) and rewrite each drawing command as absolute coordinates in the original system.	Medium6	SimulationGeometry+2	No attempts yet	1s	128 MB	Judgeable
Annoying Painting ToolGiven a target black-and-white grid and a fixed r by c flip rectangle, find the minimum number of flips to reach it, or report impossibility.	Medium6	GreedySimulation+2	No attempts yet	1s	128 MB	Judgeable