Problems

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Total results29,461 problems

Hamlet
Medium4
Dynamic programming, Probability+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Fridge Magnets
Medium4
Greedy, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
A Series of Tubes
Medium4
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Logic Puzzle
Medium4
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Stick Game
Medium4
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Galactic Confederation
Medium4
Geometry, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Counting Equilateral Triangles
Medium4
Prefix sum, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Minimum overtakes
Medium4
Sorting, Array+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rubik Cycle
Medium4
Simulation, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Complete Stars
Medium4
Number theory, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Minimum energy × delay product
Medium4
Dynamic programming, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Coast Guard
Medium4
Geometry, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Elevator
Medium4
Geometry, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Dragster
Medium4
Probability, Tree+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Minimum Queen Moves
Medium4
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Colored Cubes
Medium4
Implementation, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Perfect Crime
Medium4
BFS, Graph
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Remove Duplicates
Medium4
Hash map, Array+2
No attempts yet
Time limit
5s
Memory limit
8 MB
Judgeable
Ax+Bsin(x)=C
Medium4
Binary search, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Falling Apples
Medium4
Simulation, Implementation
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Square Deal
Medium4
Geometry, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Periodic Strings
Medium4
String, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Mismatched Socks
Medium4
Greedy, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Palindromes
Medium4
String, Two pointers+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Obfuscated Trees
Medium4
Tree, Recursion+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rasterization
Medium4
Geometry, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Era Name
Medium4
Array, Sorting+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Whist
Medium4
Simulation, Implementation+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
The Door to the Treasure Repository
Medium4
Number theory, Math+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Reading a Chord
Medium4
Hash map, Math+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Pokemon Trading
Medium4
Array, Greedy+1
No attempts yet
Time limit
0.3s
Memory limit
4 MB
Judgeable
Delete and Append Sort
Medium4
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Coordinates
Medium4
Graph, BFS+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Closing the Windows
Medium4
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Overwatch World Cup
Medium4
Implementation, Hash map
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Careful Ascent
Medium4
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Appearance Analysis
Medium4
Implementation, Matrix+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Balls and Needles
Medium4
Graph, Union-find+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Merging Files 3
Medium4
Heap, Greedy
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Contest Score
Medium4
Simulation, Heap+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Gravity
Medium4
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hidden Palindrome
Medium4
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Arrival Time
Medium4
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tandem Bicycle
Medium4
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
R9K
Medium4
String, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hyperloop
Medium4
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tunnel
Medium4
Array, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Amusement Park Queue
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Wheat Harvest
Medium4
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sum of Divisor Sums
Medium4
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Counting Haybales
Medium4
Sorting, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Moocast
Medium4
Graph, DFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Road work and the distance to the capital
Medium4
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Packing snack sticks
Medium4
Math, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The nearest convenience store
Medium4
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Box Packing
Medium4
Dynamic programming, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Christmas Gifts
Medium4
Heap, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Merging Slimes
Medium4
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Build a tree
Medium4
Tree, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jump Jump
Medium4
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Company culture 1
Medium4
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Stretch Rope (Small)
Medium4
Brute force, Array+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Safe Squares (Small)
Medium4
Dynamic programming, Matrix+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Evaluation Order of Assignments (Small)
Medium4
Graph, Topological sort+2
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Evaluation
Medium4
Graph, Topological sort+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Rebel Against The Empire (Small)
Medium4
Graph, Union-find+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Close Match (Small)
Medium4
Brute force, Implementation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
The Last Word (Large)
Medium4
Greedy, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Rank and File (Small)
Medium4
Hash map, Implementation
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Revenge of the Pancakes (Small)
Medium4
Greedy, String
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Revenge of the Pancakes (Large)
Medium4
Greedy, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Beach
Medium4
Implementation, Matrix+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Overtime
Medium4
Hash map, Stack+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Three Square
Medium4
Geometry, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Resource Mining
Medium4
Dynamic programming, Matrix+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Hoof, Paper, Scissors (Silver)
Medium4
Prefix sum, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cow Tipping
Medium4
Greedy, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Why Did the Cow Cross the Road II
Medium4
Array, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Point Card
Medium4
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hunter's Apprentice
Medium4
Geometry, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Ingenious Lottery Tickets
Medium4
Sorting, Array
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Wookje Is a Devoted Son!!
Medium4
Greedy, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Boolean Product of Boolean Matrices
Medium4
Matrix, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Gwailnori
Medium4
Simulation, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
When Geudae Becomes Geumeo
Medium4
Graph, BFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rolling a Dice
Medium4
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Robot Vacuum Cleaner
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Yin and Yang Stones
Medium4
String, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bovine Genomics (Silver)
Medium4
Brute force, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Modern Art (Bronze)
Medium4
Implementation, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Street light poles
Medium4
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Railway Station
Medium4
Stack, Simulation
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
The fastest road to Banikoara
Medium4
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tofu Game
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Additive and multiplicative inverses
Medium4
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Prerequisite Courses
Medium4
Graph, Topological sort+2
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Ieumjul
Medium4
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Club Room Project (Large)
Medium4
Union-find, Array
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Image quilting (large)
Medium4
Dynamic programming, Matrix+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pizza (Large)
Medium4
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
HamletGiven a DAG of plot states where each action gives a probability distribution over higher-numbered states, find the best expected value from state 1 and round it to two decimals.	Medium4	Dynamic programmingProbability+2	No attempts yet	3s	512 MB	Judgeable
Fridge MagnetsGiven a multiset of digit magnets, find the smallest positive integer that cannot be assembled from them, where the answer can exceed 64-bit range.	Medium4	GreedyMath+2	No attempts yet	2s	512 MB	Judgeable
A Series of TubesGiven a connected undirected graph, decide whether its edges can be oriented so that the result stays strongly connected.	Medium4	GraphDFS	No attempts yet	1s	512 MB	Judgeable
Logic PuzzleGiven a grid of variable names with row and column sums, deduce each variable's integer value by repeatedly solving rows or columns with a single unknown.	Medium4	SimulationImplementation	No attempts yet	1s	512 MB	Judgeable
Stick GameGiven counts of sticks of distinct lengths, find the maximum number of rectangles (squares allowed) that can be built using each stick at most once.	Medium4	GreedySorting	No attempts yet	2s	512 MB	Judgeable
Galactic ConfederationGiven M planes and N planet positions, count how many planets fall in the most populated region formed by the planes.	Medium4	GeometryHash map+2	No attempts yet	2s	512 MB	Judgeable
Counting Equilateral TrianglesGiven arc lengths around a circle and points at the boundaries, count equilateral triangles whose three vertices are among the points.	Medium4	Prefix sumMath+1	No attempts yet	2s	512 MB	Judgeable
Minimum overtakesGiven a starting order and a finishing order of up to 24 cars, print the minimum number of adjacent swaps that turn the start into the finish.	Medium4	SortingArray+1	No attempts yet	2s	512 MB	Judgeable
Rubik CycleFor each move sequence, find the smallest number of times it must be repeated to return the cube to its starting state.	Medium4	SimulationMath+1	No attempts yet	2s	512 MB	Judgeable
Complete StarsFor each N, count the values k with 1 <= k < N/2 whose step visits every marked point, i.e. gcd(k, N) = 1.	Medium4	Number theoryMath	No attempts yet	2s	512 MB	Judgeable
Minimum energy × delay productChoose a frequency level for each of P programs in order to minimize the total energy times delay product, including a fixed cost per frequency change.	Medium4	Dynamic programmingImplementation	No attempts yet	2s	512 MB	Judgeable
Coast GuardDecide whether a coast guard boat can intercept a thief heading straight out to sea 12 miles away, given their speeds and starting distance apart.	Medium4	GeometryMath+2	No attempts yet	2s	512 MB	Judgeable
ElevatorGiven a rectangle and two circles, decide whether both circles fit inside the rectangle without overlapping.	Medium4	GeometryMath	No attempts yet	2s	512 MB	Judgeable
DragsterGiven pairwise win probabilities and a binary elimination bracket, compute the probability that driver 1 wins the tournament.	Medium4	ProbabilityTree+1	No attempts yet	2s	512 MB	Judgeable
Minimum Queen MovesGiven a queen's start and target square on an 8x8 board, print the minimum number of queen moves needed.	Medium4	MathImplementation+1	No attempts yet	2s	512 MB	Judgeable
Colored CubesCount how many distinct cube colorings appear in each test case, where two cubes match if some rotation makes all six face colors agree.	Medium4	ImplementationHash map+1	No attempts yet	2s	512 MB	Judgeable
Perfect CrimeFind the fewest moves to go from building S to D, where each move jumps F forward or B backward, avoiding police buildings.	Medium4	BFSGraph	No attempts yet	1s	512 MB	Judgeable
Remove DuplicatesRead a space-separated list whose length is not given, keep each value only at its first occurrence, and print the surviving values in order.	Medium4	Hash mapArray+2	No attempts yet	5s	8 MB	Judgeable
Ax+Bsin(x)=CGiven A, B, C with B <= A, find the unique real x solving Ax + B*sin(x) = C, rounded to six decimals.	Medium4	Binary searchMath	No attempts yet	2s	512 MB	Judgeable
Falling ApplesLet apples fall under gravity in a grid with fixed obstacles until none can move, then print the final grid.	Medium4	SimulationImplementation	No attempts yet	5s	512 MB	Judgeable
Square DealGiven three rectangles, decide whether they can be glued edge to edge into a square, with rotations allowed.	Medium4	GeometryImplementation+1	No attempts yet	2s	512 MB	Judgeable
Periodic StringsGiven a string, find the smallest k such that cutting it into blocks of length k makes each block a one-step rotation of the previous block.	Medium4	StringBrute force+2	No attempts yet	2s	512 MB	Judgeable
Mismatched SocksGiven counts of socks per color, find the maximum number of pairs where each pair uses two different colors and every sock is in at most one pair.	Medium4	GreedyMath+1	No attempts yet	2s	512 MB	Judgeable
PalindromesFor each string, find the leftmost single-character deletion that leaves a palindrome, or report that none exists.	Medium4	StringTwo pointers+2	No attempts yet	2s	512 MB	Judgeable
Obfuscated TreesDecode a tree from its obfuscated token stream, where each internal node carries an ordering code and subtree count, then print its values in pre-order.	Medium4	TreeRecursion+1	No attempts yet	2s	512 MB	Judgeable
RasterizationCount the pixel centers inside or on a triangle with integer-coordinate corners, handling the collinear case as a segment.	Medium4	GeometryImplementation	No attempts yet	2s	512 MB	Judgeable
Era NameGiven partial records mapping Western years to era names and regnal years, determine the era name and year for each query, or report Unknown when no record covers it.	Medium4	ArraySorting+2	No attempts yet	8s	512 MB	Judgeable
WhistGiven the trump suit and the 52 cards played across 13 tricks, determine which team won and by how many tricks above six.	Medium4	SimulationImplementation+1	No attempts yet	8s	512 MB	Judgeable
The Door to the Treasure RepositoryFor each pair of integers, compute each key number (largest distinct prime factor minus the sum of the others) and print the one with the larger key.	Medium4	Number theoryMath+2	No attempts yet	8s	512 MB	Judgeable
Reading a ChordGiven a set of 3 to 5 tones, print every chord name (base chord plus optional tension) whose tone set equals the given set, in ASCII order.	Medium4	Hash mapMath+2	No attempts yet	8s	512 MB	Judgeable
Pokemon TradingWith a fixed budget, buy on one day and sell on a later day to maximize profit; report the best result rounded to two decimals.	Medium4	ArrayGreedy+1	No attempts yet	0.3s	4 MB	Judgeable
Delete and Append SortEach operation moves one element to the end. Find the minimum number of such moves needed to sort the array.	Medium4	GreedySorting	No attempts yet	2s	512 MB	Judgeable
CoordinatesGiven differences in x and y between pairs of bases, reconstruct each base's coordinate, fixing base 1 at (0,0).	Medium4	GraphBFS+2	No attempts yet	3s	512 MB	Judgeable
Closing the WindowsCount how many of the N windows end up open after each person toggles the windows whose numbers are multiples of their index.	Medium4	MathNumber theory	No attempts yet	1s	64 MB	Judgeable
Overwatch World CupOne seat in an N by N grid breaks the rule that every row and column holds each team once; find the seat and the correct shirt.	Medium4	ImplementationHash map	No attempts yet	2s	512 MB	Judgeable
Careful AscentGiven a target point and vertical strips that scale horizontal speed, find the launch horizontal velocity so the craft reaches the target at vertical speed 1.	Medium4	MathImplementation+2	No attempts yet	2s	512 MB	Judgeable
Appearance AnalysisGiven a grid of brick separators and windows, count how many distinct window designs exist, where rotations by multiples of 90 degrees count as the same design.	Medium4	ImplementationMatrix+2	No attempts yet	1s	512 MB	Judgeable
Balls and NeedlesGiven K segments in 3D defined by endpoint triples, decide whether they form a closed cycle in space and whether their projections onto the xy-plane form a closed cycle.	Medium4	GraphUnion-find+2	No attempts yet	2s	512 MB	Judgeable
Merging Files 3Given K file sizes, find the minimum total cost of repeatedly merging two files where each merge costs the sum of their sizes.	Medium4	HeapGreedy	No attempts yet	2s	512 MB	Judgeable
Contest ScoreSimulate reading problems in order but solving the shortest available one first, keeping at most k in memory, and report the total submission time.	Medium4	SimulationHeap+1	No attempts yet	2s	512 MB	Judgeable
GravityApples fall straight down until they rest on obstacles or the floor; print the final grid.	Medium4	SimulationImplementation	No attempts yet	1s	512 MB	Judgeable
Hidden PalindromeGiven a word of at most 40 lowercase letters, find the longest palindromic subsequence obtainable by deleting letters from the front and back.	Medium4	Dynamic programmingString+2	No attempts yet	2s	512 MB	Judgeable
Arrival TimeSimulate a drive that takes 2 hours normally but twice as long while traffic runs 07:00-10:00 and 15:00-19:00, given an on-the-hour, :20, or :40 departure.	Medium4	SimulationImplementation+1	No attempts yet	2s	512 MB	Judgeable
Tandem BicyclePair each Dmojistan rider with a Pegland rider to minimize or maximize the sum of the larger speed in each pair.	Medium4	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
R9KRemove known nicknames and collapse whitespace in each message, then report whether the resulting text has appeared before.	Medium4	StringHash map+2	No attempts yet	2s	512 MB	Judgeable
HyperloopFor odd N, print (N-1)/2 Hamiltonian cycles on the complete graph of N cities that partition all edges, using the given seat-walk construction.	Medium4	GreedyMath+2	No attempts yet	1s	128 MB	Judgeable
TunnelGiven the entry order and exit order of N cars through a tunnel, count how many cars must have overtaken another car.	Medium4	ArrayHash map+2	No attempts yet	2s	512 MB	Judgeable
Amusement Park QueueTwo people walk a fixed grid path one step per minute, offset by K minutes; count the minutes their cells touch in any of eight directions.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Wheat HarvestFind each connected block of 1s, order blocks by area, and label every cell with its block's rank.	Medium4	GraphDFS+1	No attempts yet	1s	128 MB	Judgeable
Sum of Divisor SumsGiven L and R, compute the sum of divisor sums f(n) for every n from L to R.	Medium4	MathNumber theory+1	No attempts yet	1s	64 MB	Judgeable
Counting HaybalesGiven N distinct haybale positions and Q interval queries, count how many positions fall inside each inclusive range [A, B].	Medium4	SortingBinary search+2	No attempts yet	2s	512 MB	Judgeable
MoocastEach cow has a point and a broadcast radius; find the starting cow whose one-way reachable set is largest.	Medium4	GraphDFS+1	No attempts yet	2s	512 MB	Judgeable
Road work and the distance to the capitalAfter each of q edge insertions and deletions, output the shortest-path distance from every city to city 1, or -1 if unreachable.	Medium4	BFSGraph+2	No attempts yet	2s	512 MB	Judgeable
Packing snack sticksGiven n and m, decide whether an n by m grid can be tiled exactly with 3-cell straight bars and L trominoes that may be rotated.	Medium4	MathGreedy+2	No attempts yet	2s	512 MB	Judgeable
The nearest convenience storeGiven an undirected weighted graph with some vertices marked as homes and others as stores, pick the home whose shortest-path distance to the nearest store is smallest, breaking ties by vertex number.	Medium4	GraphShortest path+2	No attempts yet	2s	512 MB	Judgeable
Box PackingGiven box sizes in order, find the longest subsequence where each box is strictly smaller than the next, counting boxes in the pile.	Medium4	Dynamic programmingBinary search+2	No attempts yet	2s	512 MB	Judgeable
Christmas GiftsProcess visits in order: depots add gifts to Santa's collection, and each child takes the largest gift currently held.	Medium4	HeapSimulation+1	No attempts yet	2s	512 MB	Judgeable
Merging SlimesMerge N slimes two at a time, scoring the product of merged sizes, and maximize the total score.	Medium4	GreedySorting	No attempts yet	2s	512 MB	Judgeable
Build a treeConstruct a tree on n nodes with exactly m leaves whose sorted edge list is lexicographically smallest, and print its n-1 edges.	Medium4	TreeGreedy+2	No attempts yet	2s	512 MB	Judgeable
Jump JumpGiven jump distances on a row of n stones, count how many stones are reachable from a starting stone via left or right jumps that stay on the bridge.	Medium4	GraphBFS+2	No attempts yet	2s	512 MB	Judgeable
Company culture 1Given each employee's manager and a list of praises, propagate every praise value down the whole subtree and print the total each employee receives.	Medium4	TreeDFS+2	No attempts yet	2s	512 MB	Judgeable
Stretch Rope (Small)N is at most 10, so enumerate subsets of bands and find the cheapest subset whose summed intervals contain L and whose total price is within M.	Medium4	Brute forceArray+2	No attempts yet	5s	512 MB	Judgeable
Safe Squares (Small)Count all axis-aligned D by D subgrids of an R by C grid that contain no monster cell.	Medium4	Dynamic programmingMatrix+2	No attempts yet	5s	512 MB	Judgeable
Evaluation Order of Assignments (Small)Given assignment statements where each expression is a function call, decide whether some order evaluates every variable, which fails exactly when a dependency cycle exists.	Medium4	GraphTopological sort+2	No attempts yet	5s	1024 MB	Judgeable
EvaluationGiven assignment statements where each value depends on argument variables, decide whether some evaluation order resolves every dependency.	Medium4	GraphTopological sort+1	No attempts yet	5s	512 MB	Judgeable
Rebel Against The Empire (Small)Given stationary points in 3D, find the smallest jump radius that lets you reach asteroid 1 from asteroid 0, ignoring the time limit.	Medium4	GraphUnion-find+2	No attempts yet	5s	512 MB	Judgeable
Close Match (Small)Fill in the question marks in two equal-length digit strings to minimize the absolute difference between the values, breaking ties by minimizing the first then the second.	Medium4	Brute forceImplementation+2	No attempts yet	5s	512 MB	Judgeable
The Last Word (Large)Insert each letter of S at the front or back of the growing word so the final string is as large as possible lexicographically.	Medium4	GreedyString+1	No attempts yet	5s	512 MB	Judgeable
Rank and File (Small)Given all but one of the rows and columns of a valid grid, find the missing list of N heights in increasing order.	Medium4	Hash mapImplementation	No attempts yet	5s	512 MB	Judgeable
Revenge of the Pancakes (Small)Given a stack of pancakes as a + and - string, find the fewest top-prefix flips that make every pancake happy side up.	Medium4	GreedyString	No attempts yet	5s	512 MB	Judgeable
Revenge of the Pancakes (Large)Given a stack of pancakes as a string of + and -, find the minimum number of top-prefix flips needed to make every pancake show its happy side.	Medium4	GreedyString+1	No attempts yet	5s	512 MB	Judgeable
BeachCount the hexagon edges that separate land from water, ignoring any edge on the outer border of the map.	Medium4	ImplementationMatrix+2	No attempts yet	2s	512 MB	Judgeable
OvertimeGiven timestamped enter and leave records, count overtime as unmatched leaves plus unmatched enters per name after pairing.	Medium4	Hash mapStack+2	No attempts yet	2s	512 MB	Judgeable
Three SquareGiven three rectangles, decide whether they can be rotated and placed without overlap to exactly fill a square.	Medium4	GeometryImplementation+1	No attempts yet	1s	512 MB	Judgeable
Resource MiningA robot walks from the top-left to the bottom-right cell of an N by M grid using only right and down moves; find the largest number of resource cells it can pass through.	Medium4	Dynamic programmingMatrix+2	No attempts yet	2s	256 MB	Judgeable
Hoof, Paper, Scissors (Silver)Given FJ's sequence of N gestures, find the most games Bessie can win if she switches her own gesture at most once.	Medium4	Prefix sumBrute force+1	No attempts yet	2s	512 MB	Judgeable
Cow TippingGiven an N by N grid of 0s and 1s, find the minimum number of upper-left rectangles to toggle so all cells become 0.	Medium4	GreedyArray+2	No attempts yet	2s	512 MB	Judgeable
Why Did the Cow Cross the Road IIGiven a 52-character string where each of the 26 letters appears twice, count pairs of letters whose chord crossings force their paths to intersect.	Medium4	ArrayImplementation+2	No attempts yet	2s	512 MB	Judgeable
Point CardGiven M cards with A wins out of 2N cells, pay 1 yen per flipped stamp to make at least M-1 cards hold N or more wins; minimize total cost.	Medium4	GreedySorting+1	No attempts yet	2s	512 MB	Judgeable
Hunter's ApprenticeGiven the vertices of a simple polygon in the order placed, decide whether they run counter-clockwise (print fight) or clockwise (print run).	Medium4	GeometryMath	No attempts yet	2s	512 MB	Judgeable
Ingenious Lottery TicketsCount how often each number 1 to 49 appears across n lottery entries, then pick the six most frequent, breaking ties by favoring 7 and then smaller numbers.	Medium4	SortingArray	No attempts yet	2s	512 MB	Judgeable
Wookje Is a Devoted Son!!Given edge costs of a cycle of n villages, find the minimum total cost for three travelers starting at one village to collectively visit every village.	Medium4	GreedyImplementation+2	No attempts yet	2s	512 MB	Judgeable
Boolean Product of Boolean MatricesCompute the Boolean product of two N by N 0/1 matrices and count how many entries in the result are 1.	Medium4	MatrixBrute force+1	No attempts yet	2s	512 MB	Judgeable
GwailnoriGiven each segment's bot cycle of a seconds with b active, find the earliest time to traverse all N segments in order, waiting whenever a segment is active on arrival.	Medium4	SimulationMath+2	No attempts yet	2s	512 MB	Judgeable
When Geudae Becomes GeumeoGiven N characters and M replacement pairs, find the minimum number of substitutions needed to convert character a into character b.	Medium4	GraphBFS+1	No attempts yet	2s	512 MB	Judgeable
Rolling a DiceRoll a dice on an N by M grid, updating the cell under it and the dice faces each move, and print the top face after every successful move.	Medium4	SimulationImplementation+1	No attempts yet	2s	512 MB	Judgeable
Robot Vacuum CleanerSimulate a robot vacuum that cleans cells, rotating counterclockwise and moving forward or backward, and count how many cells it cleans before stopping.	Medium4	SimulationImplementation+2	No attempts yet	2s	512 MB	Judgeable
Yin and Yang StonesGiven a circular string of black and white stones, decide whether repeated merges can reduce it to one black and one white stone.	Medium4	StringGreedy+1	No attempts yet	2s	512 MB	Judgeable
Bovine Genomics (Silver)Count triples of genome positions where no spotty cow and plain cow share the same three characters.	Medium4	Brute forceHash map+2	No attempts yet	2s	512 MB	Judgeable
Modern Art (Bronze)Given the final canvas, count how many visible colors could have been the first rectangle painted.	Medium4	ImplementationBrute force+1	No attempts yet	2s	512 MB	Judgeable
Street light polesGiven a binary r by c grid, find the minimum number of cell flips so every row has equal pole count and every column has equal pole count, or -1 if impossible.	Medium4	ImplementationMath	No attempts yet	2s	512 MB	Judgeable
Railway StationDecide for each target permutation whether coaches arriving as 1..N can leave a single dead-end siding in that order.	Medium4	StackSimulation	No attempts yet	10s	512 MB	Judgeable
The fastest road to BanikoaraGiven towns joined by undirected weighted roads, find the shortest travel distance between a named departure town and destination town.	Medium4	GraphShortest path+2	No attempts yet	2s	512 MB	Judgeable
Tofu GameSimulate the tofu game: each shouted block number selects the next reference, and print which person holds it, stopping at the terminal value.	Medium4	SimulationImplementation+2	No attempts yet	2s	128 MB	Judgeable
Additive and multiplicative inversesGiven N and A, print the additive inverse of A modulo N and the multiplicative inverse if it exists, otherwise -1.	Medium4	Number theoryMath+1	No attempts yet	1s	128 MB	Judgeable
Prerequisite CoursesGiven prerequisite pairs between courses, find the earliest semester each course can be completed when unlimited courses may be taken per semester.	Medium4	GraphTopological sort+2	No attempts yet	5s	256 MB	Judgeable
IeumjulGiven a rectangle's width and height, compute the dimensions of the poster after the folded shape is determined geometrically.	Medium4	GeometryMath+1	No attempts yet	1s	64 MB	Judgeable
Club Room Project (Large)For each action, remove all walls between rooms x and y; print how many connected room blocks remain.	Medium4	Union-findArray	No attempts yet	1s	512 MB	Judgeable
Image quilting (large)Given two grayscale overlap regions of H rows and W columns, pick one column per row so adjacent rows differ by at most one, minimizing the total squared pixel difference.	Medium4	Dynamic programmingMatrix+1	No attempts yet	1s	512 MB	Judgeable
Pizza (Large)Split a tower of N into unit towers, scoring the product of the two parts at each split, and maximize the total score.	Medium4	GreedyMath+2	No attempts yet	1s	512 MB	Judgeable