Problems

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Total results29,455 problems

Study Days
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Yes or No?
Medium5
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Throw a Party!!!
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Biomedical Engineering
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Electrical Engineering
Medium5
Geometry, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gerrymandering
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
And the Winner Is
Medium5
Implementation, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Transfer
Medium5
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Soccer
Medium5
Probability, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Battleground Preservation
Medium5
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Life Connections
Medium5
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hauling Ore
Medium5
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Balls
Medium5
Array, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Time Is Money
Medium5
Minimum spanning tree, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pirates' Path
Medium5
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Decimal to Fraction
Medium5
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jumbled Letters
Medium5
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bad Wiring
Medium5
Greedy, Bit manipulation
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Gene Shuffle
Medium5
Prefix sum, Hash map
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Collatz
Medium5
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Keylogger
Medium5
Linked list, Simulation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Baby's Blocks
Medium5
Combinatorics, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dimensional Warp Drive
Medium5
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Message
Medium5
Dynamic programming, Probability
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
ASM – The Abelian Sandpile Model
Medium5
Simulation, Queue+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Northwest Wind
Medium5
Sorting, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Stock Market
Medium5
Dynamic programming, Greedy
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Imagine
Medium5
Prefix sum, Array+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Venus Rover
Medium5
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Olympic Avenues
Medium5
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Clocks
Medium5
Brute force, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
IOIOI
Medium5
String, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
JOIOI Tower
Medium5
Greedy, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fashionista
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
JJOOII
Medium5
String, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
JOI Flag
Medium5
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Commute Route
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Stroll
Medium5
Simulation, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
RBY Pop!
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Arranging Go Stones
Medium5
Stack, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Longest Common Substring
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Quality Inspection
Medium5
Implementation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Listing Square Arrangements in Lexicographic Order
Medium5
Backtracking, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sum of a Sequence
Medium5
Math, Array+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Good Numbers
Medium5
Hash map, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Largest Prime Substring
Medium5
String, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Floodgates
Medium5
Brute force, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Drunk Coding
Medium5
Segment tree, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Jollo
Medium5
Brute force, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Klingon Course Levels
Medium5
Sorting, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pole Position
Medium5
Array, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bora Bora
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Odd or Even
Medium5
Greedy, Math+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Computer DJ
Medium5
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Child Play
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
I Hate SPAM, but Some People Love It
Medium5
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Supermarket
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Race
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Milk Scheduling
Medium5
Graph, Topological sort+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Milk Routing
Medium5
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Clumsy Cows
Medium5
Greedy, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Typo
Medium5
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bookshelf
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Islands
Medium5
Sorting, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow IDs
Medium5
Combinatorics, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Escaping the Farm
Medium5
Bit manipulation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Awkward Digits
Medium5
Brute force, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Beauty Pageant
Medium5
BFS, Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Symmetry
Medium5
Recursion, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cleaning the Dishes
Medium5
Simulation, Stack+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Line
Medium5
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Best Parenthesis
Medium5
Stack, Recursion+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Hexagonal Pasture Network
Medium5
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bovine Bridge Battle
Medium5
Hash map, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Corn Maze
Medium5
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Skewed Sorting
Medium5
Divide and conquer, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Big Dance
Medium5
Divide and conquer, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tea Time
Medium5
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Buying Feed, II
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Word Morph
Medium5
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Chocolate Giving
Medium5
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hexadecimal to Octal Conversion
Medium5
String, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Relay Race
Medium5
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Typing
Medium5
Trie, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Building a Fence
Medium5
Combinatorics, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pasture Walking
Medium5
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rubik's Cube
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Switching Lights
Medium5
Segment tree, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hay For Sale
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Patting Heads
Medium5
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Best Spot
Medium5
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cruel Math Teacher, II
Medium5
Binary search, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sand Castle
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Digit Game
Medium5
Dynamic programming, Game theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Treasure Cave
Medium5
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Cash
Medium5
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bessie's Secret Pasture
Medium5
Hash map, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Obstacle Course
Medium5
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Privileged Cows
Medium5
Greedy, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sunscreen
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Study DaysDistribute H study hours among n courses, each with 10 grade thresholds, to maximize the average grade point, rounded to two decimals.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
Yes or No?Pick between l and r questions to answer Yes, maximizing the sum of per-question expected correct probabilities, and report the maximum expectation to two decimals.	Medium5	Dynamic programmingSorting+2	No attempts yet	1s	128 MB	Judgeable
Throw a Party!!!Given friends' home regions with drunk/sober status and cars with capacity bound to regions, compute how many friends cannot be seated (each car needs a sober driver).	Medium5	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Biomedical EngineeringGiven a target string and a set of reusable component strings, find the minimum number of components whose concatenation equals the target, or report that it is impossible.	Medium5	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable
Electrical EngineeringFor each query point, find the strongest signal among routers whose segment to the point crosses no polygon wall, using 1/d^2 falloff.	Medium5	GeometryBrute force+2	No attempts yet	1s	128 MB	Judgeable
GerrymanderingSplit n precincts, each with P and Q vote counts, into two nonempty districts; find how many districts P can win (0, 1, or 2).	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
And the Winner IsEach ballot has one character per candidate; discard any ballot that marks more than one candidate in the same race, then report the top vote-getter (ties included) in every race, in input order.	Medium5	ImplementationArray+2	No attempts yet	1s	128 MB	Judgeable
TransferGiven hypertubes each connecting K stations totally, find the fewest stations visited traveling from station 1 to station N.	Medium5	BFSGraph+2	No attempts yet	2s	256 MB	Judgeable
SoccerCompute probability distribution of final scores after up to T seconds of a stochastic soccer simulation with passing, stealing, shooting, and absorbing states.	Medium5	ProbabilityDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
Battleground PreservationGiven past battle results with costs, find the cheapest chain of victories between two fighters and decide the winner, or output FIGHT! if neither dominates.	Medium5	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Life ConnectionsGiven an undirected friendship graph, count the distinct shortest paths between each queried pair of nodes, where path length counts nodes.	Medium5	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Hauling OreFor each queried mine in an undirected graph, print all mines at shortest distance exactly 2, in alphabetical order.	Medium5	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
BallsThere are n balls and n holes. Balls fall straight down from (i,h) to holes at (i,0). Placing exactly one obstacle (a segment between two integer columns) that tilts right redirects all balls in its column range to its right (lower) end; tilting left redirects them to its left (lower) end. For each orientation, maximize the total score over all valid placements (both orientations must be used, i.e., one obstacle of the specified tilt is mandatory, even if it reduces the total). Constraints n up to 3e5, c_i up to 1e9 in absolute value, so O(n log n) or O(n) required, answers in 64-bit.	Medium5	ArrayPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Time Is MoneyWe choose N-1 links forming a spanning tree minimizing SumTime*SumMoney, where each edge has a time and a money cost.	Medium5	Minimum spanning treeGeometry+2	No attempts yet	1s	128 MB	Judgeable
Pirates' PathFind the path from s to e in an undirected graph that uses the fewest guarded edges, where each edge has cost 0 or 1.	Medium5	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Decimal to FractionConvert a decimal string, with an optional repeating block in parentheses, into the exact fraction in lowest terms.	Medium5	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Jumbled LettersFor each query, find the longest dictionary word that can be formed using the query letters at most once, breaking ties alphabetically, or report IMPOSSIBLE.	Medium5	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Bad WiringEach switch toggles a window of 2D+1 lights; find the fewest flips that turn every light off, or report impossibility.	Medium5	GreedyBit manipulation	No attempts yet	3s	128 MB	Judgeable
Gene ShuffleTwo permutations of 1..N are given; split [1,N] into the shortest pieces where each piece holds the same set of genes in both. - use plain English	Medium5	Prefix sumHash map	No attempts yet	1s	128 MB	Judgeable
CollatzFor each N, count how many ropes of the Collatz graph connect holes in 1..N to holes outside 1..N.	Medium5	MathNumber theory+1	No attempts yet	1s	128 MB	Judgeable
KeyloggerA log of typed keys, arrow moves, and backspaces in a text field must be replayed to recover the final password.	Medium5	Linked listSimulation+1	No attempts yet	1s	256 MB	Judgeable
Baby's BlocksGiven a multiset of letters, find the 0-based rank of a given distinct permutation among all distinct permutations in lexicographic order.	Medium5	CombinatoricsString+1	No attempts yet	1s	128 MB	Judgeable
Dimensional Warp DriveEach warp orbit discovered by a given year can be reused, and we must find the smallest year whose orbits generate the displacement from start to target over Z_11^11.	Medium5	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
MessageGiven error and succession probabilities for a Martian alphabet, find the most likely original word for each intercepted message using maximum likelihood.	Medium5	Dynamic programmingProbability	No attempts yet	1s	128 MB	Judgeable
ASM – The Abelian Sandpile ModelDrop grains one at a time on a grid and repeatedly topple any cell over the critical height, losing grains that fall off the edge, until the pile is stable.	Medium5	SimulationQueue+2	No attempts yet	1s	128 MB	Judgeable
Northwest WindCount pairs of islands where one can sail to the other moving only east or south (both coordinates monotone between the two points).	Medium5	SortingPrefix sum+2	No attempts yet	1s	256 MB	Judgeable
Stock MarketFind the contiguous subarray with the largest sum and report its 1-based start and end indices, breaking ties by smallest start then smallest end.	Medium5	Dynamic programmingGreedy	No attempts yet	1s	256 MB	Judgeable
ImagineMaintain a 1024x1024 grid that starts as a checkerboard and process stickers plus rectangle queries for counts of each letter.	Medium5	Prefix sumArray+2	No attempts yet	1s	256 MB	Judgeable
Venus RoverChoose which stones to collect so total value is maximized, given limits on time and total lifted mass.	Medium5	Dynamic programming	No attempts yet	1s	128 MB	Judgeable
Olympic AvenuesGiven an undirected weighted graph with N up to 50, find the shortest path from S to F and, among ties, print the lexicographically smallest site sequence.	Medium5	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
The ClocksGiven nine clock dials and nine moves that each rotate a fixed subset of dials by 90 degrees, find the shortest move sequence that sets every dial back to 12 o'clock.	Medium5	Brute forceBacktracking+2	No attempts yet	1s	256 MB	Judgeable
IOIOICount the occurrences of the alternating string P_N (N+1 I's and N O's) as a substring of S, counting overlaps.	Medium5	StringSliding window+2	No attempts yet	1s	256 MB	Judgeable
JOIOI TowerGiven a string of J, O, I disks by increasing radius, find the maximum number of disjoint triples spelling JOI or IOI.	Medium5	GreedyArray+1	No attempts yet	1s	128 MB	Judgeable
FashionistaFor each day pick any clothing whose temperature range covers that day's high, maximizing the sum of absolute flashiness differences between consecutive days.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
JJOOIIFind the largest k such that k J's, then k O's, then k I's appear consecutively in the given string.	Medium5	StringPrefix sum+1	No attempts yet	1s	128 MB	Judgeable
JOI FlagCount fillings of an M by N grid with J, O, I (some cells fixed) that contain at least one L shape: J with O to its right and I below, modulo 100000.	Medium5	Dynamic programmingCombinatorics+2	No attempts yet	5s	128 MB	Judgeable
Commute RouteCount monotone lattice paths from (1,1) to (w,h) that never turn at two consecutive intersections, modulo 100000.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
StrollSimulate the letters on a grid as N successive walks from the top-left, and report the endpoint of the N-th walk.	Medium5	SimulationDynamic programming+1	No attempts yet	2s	128 MB	Judgeable
RBY Pop!Change exactly one ball's color, then repeatedly remove any run of 4 or more equal adjacent balls; minimize the number left.	Medium5	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Arranging Go StonesStones are added one by one; each even-indexed stone of a new color replaces the trailing run of the opposite color, and we count the white stones that remain.	Medium5	StackSimulation+2	No attempts yet	1s	128 MB	Judgeable
Longest Common SubstringGiven two uppercase strings of length up to 4000, find the length of the longest substring that occurs contiguously in both.	Medium5	Dynamic programmingString+2	No attempts yet	2s	256 MB	Judgeable
Quality InspectionGiven triples of parts (one of each type) with PASS or FAIL results, deduce for every part whether it is certainly good, certainly broken, or undetermined.	Medium5	ImplementationBrute force+1	No attempts yet	1s	128 MB	Judgeable
Listing Square Arrangements in Lexicographic OrderList every partition of n whose parts are non-increasing, and print the sequences in decreasing lexicographic order.	Medium5	BacktrackingRecursion+2	No attempts yet	1s	128 MB	Judgeable
Sum of a SequenceGiven an N by N table holding Ai+Aj for every pair of distinct indices and 0 on the diagonal, recover the original positive sequence A.	Medium5	MathArray+2	No attempts yet	1s	256 MB	Judgeable
Good NumbersCount the elements A_i that equal the sum of three elements appearing earlier in the sequence, where the same earlier element may be reused.	Medium5	Hash mapBrute force+2	No attempts yet	1s	128 MB	Judgeable
Largest Prime SubstringGiven a digit string, find the largest-valued contiguous substring that is prime and at most 100000.	Medium5	StringBrute force+2	No attempts yet	1s	128 MB	Judgeable
FloodgatesEach gate drains Fi per hour at fixed cost Ci when opened. For each query (V, T), find the minimum total cost whose combined capacity Fi*T covers V.	Medium5	Brute forceGreedy+2	No attempts yet	1s	128 MB	Judgeable
Drunk CodingMaintain a sequence under point updates and answer range-product sign queries (+/-/0) for each test case until EOF.	Medium5	Segment treePrefix sum+2	No attempts yet	1s	256 MB	Judgeable
JolloGiven the Princess's three cards and two of the Prince's, find the smallest unused third card that lets the Prince win at least two rounds against any order of play.	Medium5	Brute forceGreedy+2	No attempts yet	1s	128 MB	Judgeable
Klingon Course LevelsPick a score threshold T that splits every division into basic and advanced groups, minimizing the sum over divisions of \|basic - advanced\|. Output that minimum.	Medium5	SortingPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Pole PositionGiven the current race order of N cars with each car's position change from the start, reconstruct the starting grid or report that no valid grid exists.	Medium5	ArraySorting+2	No attempts yet	1s	128 MB	Judgeable
Bora BoraSimulate a children's card game with turn order, direction changes, forced draws and skips, and a fixed discard rule, and report the winner.	Medium5	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Odd or EvenPair each red number with a blue number to minimize how many pairs sum to an even value, since Mary wins those.	Medium5	GreedyMath+2	No attempts yet	3s	128 MB	Judgeable
Computer DJGiven N labeled songs, map the k-th character of the infinite string of all words over A..Z in length-then-lex order back to its song title.	Medium5	MathCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Child PlayGiven domino-like slabs, orient and order them so both rows sum equally, discarding one slab only if necessary and preferring the smallest minimum half.	Medium5	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
I Hate SPAM, but Some People Love ItSimulate SPAM spreading through a friendship graph, then for each person report the attribute earned from every message based on how many friends they forwarded it to.	Medium5	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
SupermarketGiven a shopping list and products in path order, buy the list items in order from later positions at minimum total cost, or report impossible.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
Cow RaceTwo cows run the same total time in constant-speed segments; count how many times the lead switches or is re-taken after a tie.	Medium5	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Milk SchedulingGiven task durations and precedence constraints that form a DAG, find the minimum makespan when unlimited workers milk cows in parallel.	Medium5	GraphTopological sort+2	No attempts yet	1s	128 MB	Judgeable
Milk RoutingPick a single path from node 1 to node N minimizing latency plus X divided by the path's bottleneck capacity, and floor the result.	Medium5	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Clumsy CowsGiven an even-length string of parentheses, find the minimum number of characters to flip so the string becomes balanced.	Medium5	GreedyString+2	No attempts yet	1s	128 MB	Judgeable
TypoGiven a bracket string with at most one typo, count how many single-character flips turn it into a valid balanced bracket string.	Medium5	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
BookshelfPartition the books in order into shelves whose widths sum to at most L, minimizing the total of each shelf's maximum height.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
IslandsGiven heights along a line, find the maximum number of separate exposed segments at any single rising water level.	Medium5	SortingArray+2	No attempts yet	1s	128 MB	Judgeable
Cow IDsFind the N-th smallest binary number that has exactly K one-bits and no leading zeros, then print it in binary.	Medium5	CombinatoricsMath+2	No attempts yet	1s	128 MB	Judgeable
Escaping the FarmAmong up to 20 cow weights, find the largest subset whose base-10 sum produces no carry in any digit position.	Medium5	Bit manipulationBrute force+1	No attempts yet	1s	128 MB	Judgeable
Awkward DigitsGiven a binary string and a ternary string that each differ from the true base-2 and base-3 forms of N in exactly one digit, find N.	Medium5	Brute forceMath+2	No attempts yet	1s	128 MB	Judgeable
Cow Beauty PageantGiven a grid with exactly two connected X regions, find the minimum number of dots to paint so the two regions become one.	Medium5	BFSGraph	No attempts yet	1s	128 MB	Judgeable
SymmetryCount the squares a recursive center-splitting process marks on an N by M grid, where each step splits an odd-by-odd field into four half-sized subfields.	Medium5	RecursionMath+2	No attempts yet	1s	128 MB	Judgeable
Cleaning the DishesSimulate two stacks where each wash or dry command reverses the order of the dishes it moves, then print the final cleaned pile top to bottom.	Medium5	SimulationStack+2	No attempts yet	1s	128 MB	Judgeable
Cow LineGiven N up to 20, convert between a permutation of 1..N and its lexicographic rank among all permutations, for up to 10000 queries.	Medium5	CombinatoricsMath+1	No attempts yet	1s	128 MB	Judgeable
Best ParenthesisGiven a balanced parenthesis string encoded as 0/1 values, compute its recursively defined score modulo 12345678910.	Medium5	StackRecursion+2	No attempts yet	1s	256 MB	Judgeable
Hexagonal Pasture NetworkGiven a hexagon-shaped grid of pastures, count and list all pastures at exact distance L from start H using BFS.	Medium5	GraphBFS+1	No attempts yet	1s	128 MB	Judgeable
Bovine Bridge BattleCount sets of four points that are symmetric about some center, where each point pairs with its 180-degree rotation partner.	Medium5	Hash mapGeometry+2	No attempts yet	1s	128 MB	Judgeable
Corn MazeGiven a grid with walkable cells, zero-cost paired teleporter slides, and one exit, find the minimum time from the start to the exit.	Medium5	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Skewed SortingApply a recursive swap procedure on 2^N cows, comparing equal-length halves as base-2^N numbers, and report total distance moved plus final order.	Medium5	Divide and conquerRecursion+2	No attempts yet	1s	128 MB	Judgeable
The Big DanceRepeatedly split the interval 1..N at the middle (front group gets the extra when odd), pairing cows when a group has exactly two, and add each pair's product to a running sum.	Medium5	Divide and conquerRecursion+2	No attempts yet	1s	128 MB	Judgeable
Tea TimeStarting from a graph of known meetings, two cows meet whenever they share a mutual friend, and after all rounds settle, answer queries about whether each pair has met.	Medium5	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Buying Feed, IIPick up to K pounds of feed from stores along a line, paying each store's price plus transport cost of distance carried, and minimize the total.	Medium5	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Word MorphGiven a dictionary of equal-length words, find the fewest one-letter changes needed to turn the start word into the end word through valid words.	Medium5	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
Chocolate GivingFor each of B queries on a weighted undirected graph, output the shortest distance from pasture P to pasture Q that passes through the barn at pasture 1.	Medium5	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Hexadecimal to Octal ConversionConvert a hexadecimal number of up to 100,000 digits into its octal form with no leading zeros, using binary as the intermediate step.	Medium5	StringMath+2	No attempts yet	1s	128 MB	Judgeable
Relay RaceEach cow runs one lap, then signals other cows to start; find the time when the last cow finishes, ignoring repeat signals.	Medium5	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Cow TypingGiven a dictionary and short email words, simulate the cow's letter selector with a trie and count total button presses, including circular highlight moves and prints.	Medium5	TrieString+2	No attempts yet	1s	128 MB	Judgeable
Building a FenceCount the ordered ways to cut a plank of length N into four positive integer pieces whose longest piece is strictly shorter than the other three combined.	Medium5	CombinatoricsMath+2	No attempts yet	1s	128 MB	Judgeable
Pasture WalkingGiven a weighted tree with N vertices and Q queries, find the path length between each queried pair of vertices.	Medium5	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
Rubik's CubeSimulate Rubik's Cube face turns from an unfolded starting state and print the final facelet colors in the same layout.	Medium5	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Switching LightsMaintain a binary array of N lights under M range-toggle and range-count operations, and print each query result.	Medium5	Segment treeArray+1	No attempts yet	1s	128 MB	Judgeable
Hay For SaleGiven a wagon capacity and a list of hay bale volumes, find the largest total volume not exceeding the capacity that can be formed by choosing whole bales.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
Patting HeadsEach of N cows has a value; for every cow count how many other cows hold a value that divides hers.	Medium5	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Best SpotGiven a weighted undirected graph and a set of favorite vertices, find the vertex whose average shortest-path distance to all favorites is smallest, breaking ties by smallest index.	Medium5	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Cruel Math Teacher, IIFind a real root of an odd-degree polynomial with one real root in [-1e6, 1e6], accurate to 5e-5, and print the root times 1000 truncated toward zero.	Medium5	Binary searchMath+2	No attempts yet	1s	128 MB	Judgeable
Sand CastleGiven current merlon heights and a multiset of target heights in any order, pair them to minimize the total cost of raising and lowering, where raising costs X and lowering costs Y.	Medium5	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Cow Digit GameFor each starting number, players alternately subtract its largest or smallest nonzero digit, and the player who reaches 0 wins; decide if the first player wins.	Medium5	Dynamic programmingGame theory+2	No attempts yet	1s	128 MB	Judgeable
Treasure CaveGiven a binary branching from passage 1, find the list of passages on the unique path from the entrance to passage T and its length.	Medium5	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
Cow CashCount the number of unordered ways to make an amount N using V coin denominations, where each coin can be used any number of times.	Medium5	Dynamic programmingCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Bessie's Secret PastureCount the ordered quadruples (a,b,c,d) of non-negative integers whose squares sum to N, for N up to 10000.	Medium5	Hash mapMath+2	No attempts yet	1s	128 MB	Judgeable
Obstacle CourseOn an N by N grid with blocked tiles, find a walk from A to B that minimizes the number of 90-degree turns; start and end directions are free.	Medium5	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
Privileged CowsGiven a sequence of 1s, 2s, and 3s, find the minimum number of arbitrary swaps needed to group all 1s first, then all 2s, then all 3s.	Medium5	GreedyArray+2	No attempts yet	1s	128 MB	Judgeable
SunscreenEach cow accepts an SPF interval, each bottle has an SPF value and capacity; assign bottles to maximize the number of cows covered.	Medium5	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable