Problems

Pick a problem, code in the editor, and watch the judge run real test cases. The archive is open to browse

Under construction

Still being built. Things may change

Total results29,461 problems

Irrational Roots
Medium4
Number theory, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Dr Who's Banquet
Medium4
Graph, Greedy+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Longest Prefix Match
Medium4
Trie, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Miraculous Drug
Medium4
Sliding window, Queue
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Candy Bombers
Medium4
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Television Reception
Medium4
Geometry
No attempts yet
Time limit
6s
Memory limit
256 MB
Judgeable
Lowest Common Ancestor
Medium4
Tree, DFS
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Lowest Common Ancestor 2
Medium4
Tree, DFS
No attempts yet
Time limit
1.5s
Memory limit
256 MB
Judgeable
Large Fibonacci Number Modulo
Medium4
Matrix, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Ga
Medium4
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Icelandic Motorclubs
Medium4
Greedy, Prefix sum
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Range product queries
Medium4
Segment tree
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Popping Balloons
Medium4
Greedy, Hash map
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Immortal Porpoises
Medium4
Matrix, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Farey Sequence Length
Medium4
Number theory, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
RATS sequence
Medium4
Simulation, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Word Clouds Revisited
Medium4
Dynamic programming, Prefix sum
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Competition
Medium4
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Puyo Puyo
Medium4
BFS, Simulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Polynomial Game
Medium4
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Baegyang Road Break
Medium4
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Mingyun's Scheme
Medium4
Dynamic programming, Binary search
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Ina and the Hyperdimensional War
Medium4
Matrix, Math
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Dinner Menu Roulette
Medium4
String matching, Math
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Geppetto's Pizza
Medium4
Brute force, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Triangle
Medium4
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Excellence
Medium4
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Grid Jumps
Medium4
BFS, Graph
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Six Degrees
Medium4
BFS, Graph
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Wipe Your Whiteboards
Medium4
Number theory, Math
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Time Machine
Medium4
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Table Range Sum with Updates
Medium4
Segment tree
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Two-Dimensional Range Sum
Medium4
Prefix sum, Matrix
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Points on a Segment
Medium4
Binary search, Sorting
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Kitchen Combinatorics
Medium4
Brute force, Combinatorics
No attempts yet
Time limit
4s
Memory limit
256 MB
Judgeable
Smallest third number for a given lcm
Medium4
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Euler Totient Count
Medium4
Number theory
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Generators
Medium4
Greedy, Simulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Smallest number missing from a digit sequence
Medium4
String matching, Brute force
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Rings
Medium4
BFS, Matrix+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Death Star
Medium4
Bit manipulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Shortest does not Mean the Simplest
Medium4
Number theory, Math
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Star triangles
Medium4
Hash map, Combinatorics
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Odd Even Sequence
Medium4
Math, Binary search
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Trading
Medium4
Segment tree, Intervals
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Box Splitting Game
Medium4
Game theory, Dynamic programming
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Nim Game 2
Medium4
Game theory, Bit manipulation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Multigram
Medium4
String, Hash map
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Birthday Numbers I
Medium4
Greedy, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Counting Haybales
Medium4
Segment tree
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
High Card Wins
Medium4
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Angry Cows (Silver)
Medium4
Binary search, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Subsequences Summing to Sevens
Medium4
Prefix sum, Hash map
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Collecting Stamps 2
Medium4
Prefix sum, Combinatorics
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Milk Pails
Medium4
BFS, Simulation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Stock Purchase Plan
Medium4
Dynamic programming, Binary search
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Longest Increasing Subsequence 2
Medium4
Binary search, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mileage Course Registration
Medium4
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
ABC Street
Medium4
Dynamic programming
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sums of Sums (Small)
Medium4
Sorting, Prefix sum
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Dynamic Grid (Large)
Medium4
BFS, Matrix+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
gCube (Small)
Medium4
Math
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
gCampus (Small)
Medium4
Shortest path, Graph
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
gSnake (Small)
Medium4
Simulation, Queue
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Cyclic Rotations
Medium4
String matching
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Telephones
Medium4
Greedy, Array
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Sum of Imperfections
Medium4
Number theory, Prefix sum
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Consecutive Sums
Medium4
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Pretty Good Proportion (Small)
Medium4
Brute force, Prefix sum
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
English and French (Small)
Medium4
Brute force, Bit manipulation+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Noisy Neighbors
Medium4
Brute force, Bit manipulation
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Mushroom Monster (Large)
Medium4
Greedy, Simulation+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Power Levels (Small)
Medium4
Math, Brute force
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Cube IV (Small)
Medium4
DFS, Dynamic programming+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Minesweeper Minimum Clicks
Medium4
BFS, Graph+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Minimum Clicks in Minesweeper
Medium4
DFS, Graph+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Taking Metro (Small)
Medium4
Shortest path, Graph
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Tetris Simulation
Medium4
Simulation, Matrix
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Tetris Simulation
Medium4
Simulation, Matrix+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Password Attacker (Small)
Medium4
Combinatorics, Math
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
New Year's Eve Wine Pyramid
Medium4
Simulation
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Packing Files onto Discs
Medium4
Greedy, Two pointers+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Data Packing
Medium4
Greedy, Two pointers+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Part Elf (Small)
Medium4
Math
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Enclosure
Medium4
Brute force, BFS+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Charging Chaos (Small)
Medium4
Brute force, Bit manipulation+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Cookie Farms
Medium4
Greedy, Math
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Ignore all my comments (Small)
Medium4
Stack, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Ignore all my comments (Large)
Medium4
Stack, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Rational Number Tree (Small)
Medium4
Tree, BFS+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Manage your Energy (Small)
Medium4
Dynamic programming
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Number card trick
Medium4
Brute force, Combinatorics
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Lawnmower (Small)
Medium4
Greedy, Matrix
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Lawnmower (Large)
Medium4
Greedy, Matrix
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Decomposition Sum 2
Medium4
Brute force, Math
No attempts yet
Time limit
0.25s
Memory limit
512 MB
Judgeable
Ocean View
Medium4
Dynamic programming
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Twirling Towards Freedom (Small)
Medium4
Brute force, Geometry+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Shifting Paths (Large)
Medium4
Simulation, Graph
No attempts yet
Time limit
30s
Memory limit
512 MB
Judgeable
The peak that looks highest
Medium4
Geometry, Implementation
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Diamond Inheritance (Small)
Medium4
Graph, DFS
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Irrational RootsCount how many of the n real roots of the given monic integer polynomial are irrational.	Medium4	Number theoryImplementation	No attempts yet	1s	256 MB	Judgeable
Dr Who's BanquetBuild a chat graph whose vertex degrees equal the given wishes with the stated greedy construction, or print fail.	Medium4	GraphGreedy+1	No attempts yet	1s	256 MB	Judgeable
Longest Prefix MatchGiven X bit prefixes with ids and Y destination addresses, print the id of the longest matching prefix for each address or -1.	Medium4	TrieBit manipulation	No attempts yet	1s	256 MB	Judgeable
Miraculous DrugEach hour uses the cheapest enzyme bought within the last h hours, breaking ties toward the latest hour, and reports purchase counts over a given interval.	Medium4	Sliding windowQueue	No attempts yet	1s	256 MB	Judgeable
Candy BombersAssign each pilot to at most one plane they can fly to maximize the number of planes sent.	Medium4	GraphDFS	No attempts yet	1s	256 MB	Judgeable
Television ReceptionCount households inside East Germany that lie within a West German tower radius and outside every jammer radius.	Medium4	Geometry	No attempts yet	6s	256 MB	Judgeable
Lowest Common AncestorGiven a rooted tree, answer each query with the number of the deepest vertex that is an ancestor of both given vertices.	Medium4	TreeDFS	No attempts yet	3s	256 MB	Judgeable
Lowest Common Ancestor 2Given a rooted tree with up to 100,000 nodes, answer up to 100,000 lowest common ancestor queries.	Medium4	TreeDFS	No attempts yet	1.5s	256 MB	Judgeable
Large Fibonacci Number ModuloGiven n up to 10^18, print the nth Fibonacci number modulo 1,000,000,007.	Medium4	MatrixDivide and conquer+1	No attempts yet	1s	256 MB	Judgeable
GaCount the empty squares White can reach by expanding from its stones through empty squares without crossing Black stones.	Medium4	BFSGraph+1	No attempts yet	1s	256 MB	Judgeable
Icelandic MotorclubsFind the smallest-numbered station from which a rider who takes all gas at every stop can complete one clockwise lap.	Medium4	GreedyPrefix sum	No attempts yet	3s	256 MB	Judgeable
Range product queriesAnswer range product queries modulo 1,000,000,007 on a sequence with point updates.	Medium4	Segment tree	No attempts yet	1s	256 MB	Judgeable
Popping BalloonsPop every balloon from left to right with the fewest rightward arrows that drop one unit after each hit.	Medium4	GreedyHash map	No attempts yet	2s	256 MB	Judgeable
Immortal PorpoisesFor each of up to 1000 queries, print the Y-th Fibonacci number modulo one billion, with Y up to 2^48.	Medium4	MatrixDivide and conquer+1	No attempts yet	1s	256 MB	Judgeable
Farey Sequence LengthCompute 1 plus the sum of Euler totient values up to N for each of up to 10000 data sets.	Medium4	Number theoryPrefix sum+1	No attempts yet	1s	256 MB	Judgeable
RATS sequenceSimulate up to 60 RATS steps per data set and report the first creeper term, the first repeated term, or the last term.	Medium4	SimulationString+1	No attempts yet	1s	256 MB	Judgeable
Word Clouds RevisitedPlace N ordered boxes of given widths and heights into width-limited rows to minimize the sum of row heights.	Medium4	Dynamic programmingPrefix sum	No attempts yet	2s	256 MB	Judgeable
CompetitionFind the fewest seat changes that let Alice and Bob solve every solvable problem in contest order.	Medium4	GreedySorting	No attempts yet	1s	256 MB	Judgeable
Puyo PuyoCount how many chain reactions occur when groups of four or more same-color puyos pop and gravity settles the 12 by 6 field.	Medium4	BFSSimulation	No attempts yet	1s	256 MB	Judgeable
Polynomial GameFor each test case, compute the coefficient of x^N in the product of (1+x+...+x^i) for i from 1 to k.	Medium4	Dynamic programmingCombinatorics	No attempts yet	1s	256 MB	Judgeable
Baegyang Road BreakGiven a graph with one-way and two-way roads, answer many queries for the minimum number of one-way roads to reverse to reach each destination.	Medium4	Shortest pathGraph	No attempts yet	1s	256 MB	Judgeable
Mingyun's SchemeGiven N cards in order, compute the length of the longest strictly increasing subsequence.	Medium4	Dynamic programmingBinary search	No attempts yet	1s	256 MB	Judgeable
Ina and the Hyperdimensional WarDetermine whether a target point is a nonnegative combination of triangular unit moves within the move limit and give the smallest count.	Medium4	MatrixMath	No attempts yet	5s	256 MB	Judgeable
Dinner Menu RouletteCount rotations that turn the current wheel letters into the target menu string and print the share as a reduced fraction.	Medium4	String matchingMath	No attempts yet	5s	256 MB	Judgeable
Geppetto's PizzaCount the subsets of up to 20 ingredients that contain none of the given incompatible pairs, including the empty pizza.	Medium4	Brute forceBit manipulation	No attempts yet	1s	64 MB	Judgeable
TriangleDecide whether two given integer-sided triangles are congruent right triangles that can form a rectangle split along its diagonal.	Medium4	GeometryMath+1	No attempts yet	2s	256 MB	Judgeable
ExcellencePair all students into teams of two so the smallest team rating sum is as large as possible.	Medium4	GreedySorting+1	No attempts yet	2s	256 MB	Judgeable
Grid JumpsFind the fewest digit-length jumps from the top-left cell to the bottom-right cell of a grid, or print IMPOSSIBLE.	Medium4	BFSGraph	No attempts yet	2s	256 MB	Judgeable
Six DegreesCount the devices that cannot reach every other device within 6 hops and answer YES when they are at most 5 percent of the network.	Medium4	BFSGraph	No attempts yet	2s	256 MB	Judgeable
Wipe Your WhiteboardsGiven R, S and Q, find positive integers A and B with A R + B S equal to Q, minimizing A first and then B.	Medium4	Number theoryMath	No attempts yet	5s	256 MB	Judgeable
Time MachineCompute the fastest times from city 1 over bus routes with possibly negative durations, or print -1 when a reachable negative cycle exists.	Medium4	Shortest pathGraph	No attempts yet	1s	256 MB	Judgeable
Table Range Sum with UpdatesApply point updates on an N by N table and answer each rectangle sum query in order.	Medium4	Segment tree	No attempts yet	1s	256 MB	Judgeable
Two-Dimensional Range SumCompute the sum of each queried rectangle in an N by N table using a 2D prefix sum.	Medium4	Prefix sumMatrix	No attempts yet	1s	256 MB	Judgeable
Points on a SegmentCount how many of N distinct points fall inside each of M closed intervals on a line.	Medium4	Binary searchSorting	No attempts yet	1s	256 MB	Judgeable
Kitchen CombinatoricsCount compatible starter, main and dessert triples weighted by brand choices over shared ingredients, printing too many above 10^18.	Medium4	Brute forceCombinatorics	No attempts yet	4s	256 MB	Judgeable
Smallest third number for a given lcmFind the smallest positive integer c with lcm(a, b, c) equal to L, or output -1 when none exists.	Medium4	Number theoryMath	No attempts yet	1s	256 MB	Judgeable
Euler Totient CountCount integers k from 1 to n that are coprime to n.	Medium4	Number theory	No attempts yet	1s	256 MB	Judgeable
GeneratorsSimulate each bounded generator to find its largest reachable value, then lower one value by the smallest loss that breaks divisibility by k.	Medium4	GreedySimulation	No attempts yet	1s	256 MB	Judgeable
Smallest number missing from a digit sequenceGiven up to 1000 digits, find the smallest non-negative integer that never occurs as a consecutive block without a leading zero.	Medium4	String matchingBrute force	No attempts yet	1s	256 MB	Judgeable
RingsLabel each tree square with its edge-step distance to the nearest empty square or the outside of the grid and print the dot-padded grid.	Medium4	BFSMatrix+1	No attempts yet	1s	256 MB	Judgeable
Death StarRecover the lexicographically smallest sequence whose pairwise bitwise AND values match the given off-diagonal matrix.	Medium4	Bit manipulation	No attempts yet	1s	256 MB	Judgeable
The Shortest does not Mean the SimplestGiven A, B and C up to 10^18, compute the remainder of A to the power B divided by C.	Medium4	Number theoryMath	No attempts yet	2s	256 MB	Judgeable
Star trianglesFor each star taken as the right-angle vertex, multiply the counts of other stars sharing its column and its row, then add the products.	Medium4	Hash mapCombinatorics	No attempts yet	2s	256 MB	Judgeable
Odd Even SequenceFind the Nth term of the increasing sequence formed by blocks of 1 odd, 2 evens, 3 odds, and so on.	Medium4	MathBinary search	No attempts yet	2s	256 MB	Judgeable
TradingEach trader covers villages L to R with a price that rises by 1 per village, and each village reports the highest price ever asked there.	Medium4	Segment treeIntervals	No attempts yet	2s	64 MB	Judgeable
Box Splitting GameDecide whether the first or second player wins the two-box stone-splitting game from starting counts N and M.	Medium4	Game theoryDynamic programming	No attempts yet	2s	512 MB	Judgeable
Nim Game 2Two players alternately remove stones from one of N piles and the player taking the last stone wins, so decide the winner under optimal play.	Medium4	Game theoryBit manipulation	No attempts yet	2s	512 MB	Judgeable
MultigramDecide whether the word splits into two or more equal anagram blocks and print the shortest such block, or -1.	Medium4	StringHash map	No attempts yet	1s	64 MB	Judgeable
Birthday Numbers IFind the numerically smallest number made only of digits 3, 5 and 8 whose digits add up to N, or -1 when none exists.	Medium4	GreedyMath	No attempts yet	1s	256 MB	Judgeable
Counting HaybalesApply range additions to N fields and answer Q range-minimum and range-sum queries in order.	Medium4	Segment tree	No attempts yet	2s	512 MB	Judgeable
High Card WinsAssign each of Bessie's N cards to a round against Elsie's fixed play order to win the most rounds with the higher card.	Medium4	GreedySorting	No attempts yet	2s	512 MB	Judgeable
Angry Cows (Silver)Find the smallest integer blast radius R so K intervals of length 2R cover all N hay bale positions on a line.	Medium4	Binary searchGreedy+1	No attempts yet	2s	512 MB	Judgeable
Subsequences Summing to SevensFind the length of the longest contiguous group of cows whose IDs sum to a multiple of 7.	Medium4	Prefix sumHash map	No attempts yet	2s	512 MB	Judgeable
Collecting Stamps 2Insert one J, O, or I stamp at any position to maximize the number of triples that read J, O, I in order.	Medium4	Prefix sumCombinatorics	No attempts yet	2s	256 MB	Judgeable
Milk PailsFill, empty, and pour two pails of sizes X and Y within K moves to get a combined amount as close to M as possible.	Medium4	BFSSimulation	No attempts yet	2s	512 MB	Judgeable
Stock Purchase PlanFor each test case, decide whether the daily prices contain a strictly increasing subsequence of length K.	Medium4	Dynamic programmingBinary search	No attempts yet	5s	512 MB	Judgeable
Longest Increasing Subsequence 2Given up to 1,000,000 numbers, compute the length of the longest strictly increasing subsequence.	Medium4	Binary searchDynamic programming	No attempts yet	1s	512 MB	Judgeable
Mileage Course RegistrationGiven each course rival bids and capacity, bid 1 to 36 points per chosen course, winning ties, to take the most courses with m points.	Medium4	GreedySorting	No attempts yet	1s	128 MB	Judgeable
ABC StreetStarting from block 1, hop forward across A, B, C blocks in repeating order to reach block N while minimizing the sum of squared jump lengths.	Medium4	Dynamic programming	No attempts yet	2s	512 MB	Judgeable
Sums of Sums (Small)You sort every contiguous subarray sum of an array and answer range sums over the sorted list.	Medium4	SortingPrefix sum	No attempts yet	5s	512 MB	Judgeable
Dynamic Grid (Large)Point updates flip binary grid cells and each query asks for the number of edge-connected groups of 1s.	Medium4	BFSMatrix+1	No attempts yet	5s	512 MB	Judgeable
gCube (Small)Compute the geometric mean of each queried subarray and print it with nine digits after the decimal point.	Medium4	Math	No attempts yet	5s	512 MB	Judgeable
gCampus (Small)For each road, decide whether it lies on a shortest path between some pair of offices and list the ones that never do.	Medium4	Shortest pathGraph	No attempts yet	5s	512 MB	Judgeable
gSnake (Small)Simulate a growing snake that eats food on alternating cells of a wrapping board with scheduled turns and report its length when it collides or time runs out.	Medium4	SimulationQueue	No attempts yet	5s	512 MB	Judgeable
Cyclic RotationsCount the left rotations of binary string B that exactly equal binary string A.	Medium4	String matching	No attempts yet	2s	512 MB	Judgeable
TelephonesAdd the fewest phones to empty desks so a ring hops from the first desk to the last with each hop spanning at most D.	Medium4	GreedyArray	No attempts yet	1s	64 MB	Judgeable
Sum of ImperfectionsAdd up, for every integer from A to B, the absolute gap between the number and the sum of its proper divisors.	Medium4	Number theoryPrefix sum	No attempts yet	3s	128 MB	Judgeable
Consecutive SumsPrint every run of two or more consecutive positive integers that sums to N, ordered by starting value.	Medium4	MathNumber theory	No attempts yet	1s	64 MB	Judgeable
Pretty Good Proportion (Small)Given a binary string and a target fraction F, find the start index of the contiguous substring whose share of 1s is closest to F.	Medium4	Brute forcePrefix sum	No attempts yet	5s	512 MB	Judgeable
English and French (Small)Assign each unknown sentence to English or French so the number of words appearing in both languages is as small as possible.	Medium4	Brute forceBit manipulation+1	No attempts yet	5s	512 MB	Judgeable
Noisy NeighborsPlace N tenants on an R by C grid to minimize the number of shared walls between occupied neighbors.	Medium4	Brute forceBit manipulation	No attempts yet	5s	512 MB	Judgeable
Mushroom Monster (Large)From plate counts taken every 10 seconds, compute the minimum mushrooms eaten under free eating and under the smallest consistent constant rate.	Medium4	GreedySimulation+1	No attempts yet	5s	512 MB	Judgeable
Power Levels (Small)For each given digit count D, find the smallest E whose 9000 multifactorial has fewer digits, or output dots when none exists.	Medium4	MathBrute force	No attempts yet	5s	512 MB	Judgeable
Cube IV (Small)Given a square grid holding 1 to S squared, find the smallest start of the longest chain that steps to an orthogonal neighbor one higher and report its length.	Medium4	DFSDynamic programming+1	No attempts yet	5s	512 MB	Judgeable
Minesweeper Minimum ClicksCount the minimum clicks to reveal all safe cells, where each zero region opens with one click and each leftover numbered cell needs its own.	Medium4	BFSGraph+1	No attempts yet	5s	512 MB	Judgeable
Minimum Clicks in MinesweeperFind the fewest clicks that reveal every safe cell, since one click opens each zero region and each remaining safe cell costs one click.	Medium4	DFSGraph+1	No attempts yet	5s	512 MB	Judgeable
Taking Metro (Small)Find the fastest route between two metro stations, combining per-line boarding waits, ride times, and tunnel walks.	Medium4	Shortest pathGraph	No attempts yet	5s	512 MB	Judgeable
Tetris SimulationSimulate falling tetrominoes on a small board, clear full rows after each drop, and print the final field or game over.	Medium4	SimulationMatrix	No attempts yet	5s	512 MB	Judgeable
Tetris SimulationTetrominoes with given type, rotation, and column drop straight down onto a W by H board with full lines cleared, and the final board or game over is reported.	Medium4	SimulationMatrix+1	No attempts yet	5s	512 MB	Judgeable
Password Attacker (Small)Count length-N strings over M given symbols that use every symbol at least once, modulo 1e9+7.	Medium4	CombinatoricsMath	No attempts yet	5s	512 MB	Judgeable
New Year's Eve Wine PyramidWine poured into the top glass of a pyramid of glasses overflows in equal thirds to the level below, and each query asks how much one glass holds.	Medium4	Simulation	No attempts yet	5s	512 MB	Judgeable
Packing Files onto DiscsPack all files onto the fewest discs of capacity X with at most two files per disc.	Medium4	GreedyTwo pointers+1	No attempts yet	5s	512 MB	Judgeable
Data PackingPack files onto discs holding at most two files of total size X using the fewest discs.	Medium4	GreedyTwo pointers+1	No attempts yet	5s	512 MB	Judgeable
Part Elf (Small)Given a claimed elf ancestry fraction P/Q, find the fewest generations back a full elf ancestor could have lived, or report the fraction as impossible.	Medium4	Math	No attempts yet	5s	512 MB	Judgeable
EnclosurePlace the fewest stones on an N by M grid of at most 20 cells so at least K points are cut off from the border.	Medium4	Brute forceBFS+1	No attempts yet	5s	512 MB	Judgeable
Charging Chaos (Small)Find the fewest bit positions to flip so the outlet strings match the device strings after reordering.	Medium4	Brute forceBit manipulation+1	No attempts yet	5s	512 MB	Judgeable
Cookie FarmsDecide how many cookie farms to buy before waiting so the time to hold X cookies is as short as possible.	Medium4	GreedyMath	No attempts yet	5s	512 MB	Judgeable
Ignore all my comments (Small)Remove every nested /* */ comment block from the document with a single left to right scan and print the rest unchanged.	Medium4	StackString+1	No attempts yet	5s	512 MB	Judgeable
Ignore all my comments (Large)Remove every nested /* */ comment block from the document in a single left-to-right pass and print the remaining text unchanged.	Medium4	StackString+1	No attempts yet	5s	512 MB	Judgeable
Rational Number Tree (Small)Given the level-order listing of the rational number tree, find the n-th fraction and the position of a given fraction.	Medium4	TreeBFS+1	No attempts yet	5s	512 MB	Judgeable
Manage your Energy (Small)Allocate limited energy across ordered activities, regaining R after each up to cap E, to maximize value times energy spent.	Medium4	Dynamic programming	No attempts yet	5s	512 MB	Judgeable
Number card trickChoose the sorted N-number multiset bounded by M whose subset product counts give the largest posterior weight.	Medium4	Brute forceCombinatorics	No attempts yet	5s	512 MB	Judgeable
Lawnmower (Small)Decide if row and column cuts of a mower that only lowers grass can produce the given target heights from a uniform lawn.	Medium4	GreedyMatrix	No attempts yet	5s	512 MB	Judgeable
Lawnmower (Large)Decide whether a target grid of grass heights is reachable from height 100 by cutting whole rows or columns down to chosen levels.	Medium4	GreedyMatrix	No attempts yet	5s	512 MB	Judgeable
Decomposition Sum 2Find the smallest M with M plus its digit sum equal to N, or print 0 when no such M exists.	Medium4	Brute forceMath	No attempts yet	0.25s	512 MB	Judgeable
Ocean ViewDestroy as few houses as possible so the heights of the houses left standing grow strictly from the lake eastward.	Medium4	Dynamic programming	No attempts yet	5s	512 MB	Judgeable
Twirling Towards Freedom (Small)Each minute you may stay put or rotate 90 degrees clockwise around one of the stars to maximize the distance from the origin after M minutes.	Medium4	Brute forceGeometry+1	No attempts yet	5s	512 MB	Judgeable
Shifting Paths (Large)Count how many paths the alternating left-right walk takes from clearing 1 to clearing N, or report Infinity if it never arrives.	Medium4	SimulationGraph	No attempts yet	30s	512 MB	Judgeable
The peak that looks highestGiven each peak's apparent highest peak ahead, build heights with the stated rule and print Impossible when they disagree with the memory.	Medium4	GeometryImplementation	No attempts yet	5s	512 MB	Judgeable
Diamond Inheritance (Small)Decide whether any pair of classes in each inheritance diagram has two distinct inheritance paths between them.	Medium4	GraphDFS	No attempts yet	5s	512 MB	Judgeable