Problems

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Total results29,413 problems

Generator Tree
Medium6
Tree, Hash map+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Hamilton - The Musical
Medium6
Graph, Matrix
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
Joining Pairs
Medium6
Stack, Sorting+1
No attempts yet
Time limit
0.2s
Memory limit
1024 MB
Judgeable
Scouts
Medium6
Dynamic programming, Tree
No attempts yet
Time limit
9s
Memory limit
256 MB
Judgeable
Insects
Medium6
Graph, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Blocks
Medium6
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
1.5s
Memory limit
256 MB
Judgeable
Find the String
Medium6
String matching, Hash map+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Coloring
Medium6
Matrix, Simulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Intervals
Medium6
Intervals, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Unifying Values
Medium6
Prefix sum, Hash map+2
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Young Zebra
Medium6
BFS, Matrix+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
optimizing
Medium6
Math, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Homework
Medium6
Sorting, Binary search
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Land Purchase
Medium6
Prefix sum, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Music Playlist
Medium6
Dynamic programming, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
x
Medium6
Geometry, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Antennas
Medium6
BFS, Graph+1
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
Software Package Manager
Medium6
Tree, Segment tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Homeric Epics
Medium6
Greedy, Heap
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Chain Reactions
Medium6
Tree, Greedy+1
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Pancake Deque
Medium6
Dynamic programming, Array
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Controlled Inflation
Medium6
Dynamic programming, Array+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
ASeDatAb
Medium6
Bit manipulation, Implementation
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
TOO EASY Cookie Run
Medium6
Binary search, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Squary
Medium6
Math, Implementation
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Bratski Sets
Medium6
Number theory, Combinatorics+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Wooden Planks
Medium6
Sorting, Intervals+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Flexible Ficus
Medium6
Bit manipulation, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Idyllic hedge
Medium6
Dynamic programming, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Barrel
Medium6
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Joško
Medium6
Dynamic programming, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Superheroes
Medium6
Stack, Intervals+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Robot
Medium6
Math, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hulja
Medium6
Backtracking, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Kuki's Struggle to Open a Restaurant
Medium6
Sorting, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cynical Frog
Medium6
BFS, Graph+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Gambler Gomgom
Medium6
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Colors
Medium6
Graph, Union-find+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Double Attendance
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Contact Tracing
Medium6
Backtracking, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rafting Trip
Medium6
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ranked Choice Spoiling
Medium6
Simulation, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tic Tac Toe Counting
Medium6
Brute force, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Transparency
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Gahee and the Subway
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Index Case
Medium6
Dynamic programming, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Patrick's Triangle
Medium6
Combinatorics, Math
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Box and Arrow Diagram
Medium6
Graph, BFS+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Sperhling
Medium6
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Take a break!
Medium6
Greedy, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pixelated Circle
Medium6
Math, Geometry+1
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Duck, Duck, Geese
Medium6
Sliding window, Two pointers+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
N-Sumaehwa Sword Technique
Medium6
Greedy, Geometry
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
functionx
Medium6
Sorting, Binary search+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sorting Numbers with Perfect Squares
Medium6
Number theory, Sorting+1
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Frog
Medium6
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mountain Climbing Game
Medium6
Greedy, Simulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Transfer Station Game
Medium6
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Interactive Treasure Hunt
Medium6
Math, Implementation
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Eat More Apples
Medium6
Game theory, Bit manipulation+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
ABBC
Medium6
Greedy, String+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Raspberry Pie
Medium6
Greedy, Array+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Special Prize
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Connected Car Experiment
Medium6
Graph, BFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Tree and Queries
Medium6
Tree, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Homework
Medium6
Tree, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Count of Integers Called Until the End
Medium6
Dynamic programming, Game theory+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Digesta
Medium6
Sorting, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
XOR Game
Medium6
Segment tree, Trie+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Rare Insects
Medium6
Array, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
The Magician
Medium6
String, Dynamic programming+1
No attempts yet
Time limit
30s
Memory limit
512 MB
Judgeable
Vinjete
Medium6
Tree, DFS+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Snagator
Medium6
Graph, Topological sort+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Curious Shift
Medium6
Math, String matching
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Točkice (Dot Game)
Medium6
Geometry, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
NMABCD
Medium6
Graph, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Inversions
Medium6
Sliding window, Array+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Paths
Medium6
Tree, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hilbert
Medium6
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
MANCE
Medium6
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Watt
Medium6
Segment tree, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Twinkle Twinkle 3
Medium6
Probability, Tree+1
No attempts yet
Time limit
4s
Memory limit
1536 MB
Judgeable
Score of a Sequence
Medium6
Sorting, Stack+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Power Line Connection
Medium6
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Optimal route and queries
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Sticks
Medium6
Sorting, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Pawnshop
Medium6
Dynamic programming, Sliding window
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Audience Queue
Medium6
Dynamic programming, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Make an X
Medium6
Sorting, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
MMST
Medium6
Graph, Minimum spanning tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tree MEX
Medium6
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Phoenix Stacks
Medium6
Array, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Number Guessing Game
Medium6
Dynamic programming, Probability
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pass
Medium6
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
AND, OR, XOR
Medium6
Bit manipulation, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gimbap
Medium6
Sorting, Prefix sum
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Fold
Medium6
Array, Simulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Circuits
Medium6
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bipartite Graph Game
Medium6
Sorting, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
pqbd
Medium6
String, String matching
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Generator TreeGiven N trees, count for each tree how many other trees in the collection can be built by joining copies of it with added edges.	Medium6	TreeHash map+1	No attempts yet	5s	1024 MB	Judgeable
Hamilton - The MusicalFind the cheapest Hamiltonian path over N cities where position i holds city i for every even i.	Medium6	GraphMatrix	No attempts yet	0.1s	1024 MB	Judgeable
Joining PairsGiven pairs of points on a W by H sheet of graph paper, decide whether each pair can be joined by lines inside the paper that never touch each other.	Medium6	StackSorting+1	No attempts yet	0.2s	1024 MB	Judgeable
ScoutsArrange scouts 1 to n into a binary search tree by index so the largest root-to-node sum of reading times is as small as possible.	Medium6	Dynamic programmingTree	No attempts yet	9s	256 MB	Judgeable
InsectsEach insect dies to one attractor, feed, and poison triple; choose ingredients to maximize p times insects killed minus the ingredient costs.	Medium6	GraphBit manipulation	No attempts yet	1s	128 MB	Judgeable
BlocksCount permutations of 1 to n with exactly l left-to-right maxima and p right-to-left maxima, modulo 1e9+7, for up to 100000 queries.	Medium6	CombinatoricsDynamic programming+1	No attempts yet	1.5s	256 MB	Judgeable
Find the StringCount substrings of T that have the same equality pattern as P, meaning they are a bijective relabeling of P's letters. Lengths are up to 1,000,000.	Medium6	String matchingHash map+1	No attempts yet	3s	1024 MB	Judgeable
ColoringGiven a grid with blocked cells, decide whether straight-line moves from some start can color every open cell both yellow and blue.	Medium6	MatrixSimulation+1	No attempts yet	2s	1024 MB	Judgeable
IntervalsFor each non-empty subset of the intervals, sum the intersection lengths and count those of length at least 1, modulo 1000000007.	Medium6	IntervalsSorting+2	No attempts yet	1s	1024 MB	Judgeable
Unifying ValuesCount the ways to split a sequence of N integers into two or more contiguous parts with equal sums, modulo 1,000,000,007.	Medium6	Prefix sumHash map+2	No attempts yet	0.5s	1024 MB	Judgeable
Young ZebraGiven a black and white N by M pattern tiled infinitely, print each cell's connected component size, or -1 if the component is infinite.	Medium6	BFSMatrix+1	No attempts yet	0.5s	1024 MB	Judgeable
optimizingGiven n below 2^63, return the digit at index n (0-indexed) of the string formed by concatenating g(0), g(1), g(2), ... where g(k) is the sum of cubes below k.	Medium6	MathBinary search+1	No attempts yet	2s	1024 MB	Judgeable
HomeworkFind a question list and an asking order so that all N students answer YES, using at most N + N log2 N calls to ask.	Medium6	SortingBinary search	No attempts yet	3s	1024 MB	Judgeable
Land PurchaseGiven an r by s grid of cell prices and two numbers a and b, find the nonempty rectangle whose total price minimizes \|x-a\| + \|x-b\|.	Medium6	Prefix sumTwo pointers+1	No attempts yet	2s	512 MB	Judgeable
Music PlaylistFind the maximum sum of preference values when Mingyu can jump back to an earlier song at most two times, with no song heard three or more times.	Medium6	Dynamic programmingGreedy	No attempts yet	1s	1024 MB	Judgeable
xChoose a 90-degree sector at the origin and a telescope with squared radius P_i to maximize the star beauty sum minus the telescope price.	Medium6	GeometrySorting+1	No attempts yet	3s	1024 MB	Judgeable
AntennasFind the fewest hops to send a message from antenna a to antenna b, where two antennas link when their distance is at most the smaller power.	Medium6	BFSGraph+1	No attempts yet	4s	2048 MB	Judgeable
Software Package ManagerGiven a rooted dependency tree of packages, count how many packages change status on each install or uninstall query, where installs pull in uninstalled ancestors and uninstalls remove installed descendants.	Medium6	TreeSegment tree+1	No attempts yet	1s	1024 MB	Judgeable
Homeric EpicsAssign each word a k-ary prefix-free code so the total weighted length is minimal, then report the smallest possible length of the longest code.	Medium6	GreedyHeap	No attempts yet	1s	1024 MB	Judgeable
Chain ReactionsGiven modules that each point to a lower-indexed module or the abyss, find the maximum sum of chain-reaction maxima over all orders of triggering the initiators.	Medium6	TreeGreedy+1	No attempts yet	Not set	1024 MB	Judgeable
Pancake DequeGiven a deque of pancakes, serve from either end to maximize the customers whose pancake is at least as large as every earlier one. Output that count.	Medium6	Dynamic programmingArray	No attempts yet	20s	1024 MB	Judgeable
Controlled InflationGiven customers whose products must be visited in customer order from a pump starting at 0, find the fewest up and down presses needed to hit every target pressure.	Medium6	Dynamic programmingArray+1	No attempts yet	5s	1024 MB	Judgeable
ASeDatAbInteractive task: reset an 8-bit record to zero using at most 300 rotated-XOR operations, reading the popcount after each one.	Medium6	Bit manipulationImplementation	No attempts yet	10s	1024 MB	Judgeable
TOO EASY Cookie RunFind the smallest X added to every stage so that at least K contiguous sections have a sum of at least M.	Medium6	Binary searchTwo pointers+1	No attempts yet	2s	1024 MB	Judgeable
SquaryGiven a list and a limit K, append between 1 and K integers so the square of the total equals the sum of squares, or report that it is impossible.	Medium6	MathImplementation	No attempts yet	Not set	1024 MB	Judgeable
Bratski SetsFor each prefix of a permutation of 1 to n, count the nonempty subsets whose elements share a common divisor greater than 1, modulo 998244353.	Medium6	Number theoryCombinatorics+1	No attempts yet	1.5s	1024 MB	Judgeable
Wooden PlanksGiven vertical logs, find the lowest horizontal cut line where the total length of the shorter pieces equals k, or report -1 if none exists.	Medium6	SortingIntervals+1	No attempts yet	1.5s	1024 MB	Judgeable
Flexible FicusGiven a tree with node values F_i, keep at least k nodes in one connected piece and maximize the bitwise AND of their values.	Medium6	Bit manipulationGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Idyllic hedgeCount the valid ways to trim the hedge for each total height X from 0 to S, where a cut at height v forces taller neighbors to be cut at v too.	Medium6	Dynamic programmingImplementation	No attempts yet	1s	1024 MB	Judgeable
BarrelFind the fewest tips needed to move a barrel across a grid from S to F, where the allowed rolls and tips depend on the direction of the last tip.	Medium6	BFSGraph+1	No attempts yet	1s	1024 MB	Judgeable
JoškoFind the minimum time to walk from the left end of the top segment to the right end of the bottom segment, falling between segments at any point.	Medium6	Dynamic programmingSorting	No attempts yet	1s	1024 MB	Judgeable
SuperheroesGiven skyscraper heights and hero positions, count the skyscrapers no hero can jump to, and find how many heroes can be removed without changing that count.	Medium6	StackIntervals+1	No attempts yet	2s	1024 MB	Judgeable
RobotBuild a grid maze of 0s and 1s, at most 1000 by 1000, so that exactly K right-or-down paths lead from the top-left to the bottom-right cell.	Medium6	MathDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
HuljaFind the lexicographically smallest word of length up to D by walking an 8-direction path on a letter grid without reusing cells, padding with Z.	Medium6	BacktrackingDFS+2	No attempts yet	1s	1024 MB	Judgeable
Kuki's Struggle to Open a RestaurantPlace the restaurant at a point off both axes so that the gap between the largest and smallest quadrant hunger sums is as small as possible.	Medium6	SortingPrefix sum+1	No attempts yet	2s	512 MB	Judgeable
Cynical FrogFind the fewest jumps from the start cell to home on a grid where each cell fixes a jump length, with one skip that lets the frog move any distance in a straight line.	Medium6	BFSGraph+1	No attempts yet	1.5s	1024 MB	Judgeable
Gambler GomgomGiven Gomgom's N cards with values from 1 to M, count the N-card hands you can draw that let Gomgom win, modulo 1000000007.	Medium6	Dynamic programmingCombinatorics	No attempts yet	1s	1024 MB	Judgeable
ColorsDecide whether a target coloring can be reached when each edge lets a node take the smaller color of a neighbor.	Medium6	GraphUnion-find+1	No attempts yet	3s	512 MB	Judgeable
Double AttendanceGiven slide intervals in two classrooms and a switching time K, find the maximum number of slides you can see while moving between the rooms.	Medium6	Dynamic programmingGreedy+1	No attempts yet	3s	1024 MB	Judgeable
Contact TracingGiven contacts by day, find everyone who could catch the disease on day k from some Patient Zero, and list them for quarantine.	Medium6	BacktrackingGraph+1	No attempts yet	1s	1024 MB	Judgeable
Rafting TripGiven a grid of river arrows and sightseeing spots, find the start cell whose raft path passes the most distinct spots adjacent to it.	Medium6	GraphDFS+1	No attempts yet	1s	1024 MB	Judgeable
Ranked Choice SpoilingDecide whether a new candidate Z, inserted anywhere in each voter's ranking, can make ranked choice voting elect candidate A.	Medium6	SimulationBrute force	No attempts yet	1s	1024 MB	Judgeable
Tic Tac Toe CountingGiven 3x3 Tic Tac Toe boards, check whether each is reachable in a legal game, then count the continuations that end in an X win and an O win.	Medium6	Brute forceDynamic programming+1	No attempts yet	3s	1024 MB	Judgeable
TransparencyGiven a station graph with uppercase and lowercase edge labels, find the shortest pair of distinct accepted strings whose uppercase letters match, or report -1.	Medium6	GraphShortest path+1	No attempts yet	6s	1024 MB	Judgeable
Gahee and the SubwayGiven N subway lines and Q queries, find the minimum travel time between two stations at 2 minutes per adjacent stop, or -1 if the trip is impossible.	Medium6	GraphShortest path+1	No attempts yet	1.5s	512 MB	Judgeable
Index CaseGiven a cyclic cellular automaton rule f with m states and a state s0 on n cells, decide whether some state s-1 maps to s0 under f.	Medium6	Dynamic programmingBrute force+1	No attempts yet	1s	1024 MB	Judgeable
Patrick's TriangleFor each query, decide whether X equals the K-th number on row N of Patrick's triangle modulo 1e9+7, given edges of triangular numbers and Pascal-style sums.	Medium6	CombinatoricsMath	No attempts yet	3s	1024 MB	Judgeable
Box and Arrow DiagramArrows are deleted over time, and each query asks how many arrows from live objects point to a given box. Live means reachable from box 1.	Medium6	GraphBFS+1	No attempts yet	4s	1024 MB	Judgeable
SperhlingGiven a mistyped string S1 and the intended string S2, find the fewest key presses (arrows, backspace, letters) to turn S1 into S2 with the cursor ending at the end of S2.	Medium6	Dynamic programmingString	No attempts yet	1s	1024 MB	Judgeable
Take a break!Schedule chores so the k-th task in a row costs d·2^k seconds and each one-hour break costs 3600 seconds. Find the minimum total time.	Medium6	GreedyDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Pixelated CircleGiven radius R, count the pixels that differ between a filled circle drawn by rounding distances and one built by stacking perimeter circles of radii 0 to R.	Medium6	MathGeometry+1	No attempts yet	Not set	1024 MB	Judgeable
Duck, Duck, GeeseCount the contiguous circular arcs of 2 to N-1 sitting players where each hat color appears either 0 times or within its [A_i, B_i] range.	Medium6	Sliding windowTwo pointers+1	No attempts yet	20s	1024 MB	Judgeable
N-Sumaehwa Sword TechniqueOrder N weighted line segments so that the total cost is minimized, where each stroke costs its weight times one plus the number of unperformed segments it crosses.	Medium6	GreedyGeometry	No attempts yet	2s	1024 MB	Judgeable
functionxMultiply a polynomial by linear factors (ax+b) online, and for each query report whether f(c) is negative, zero, or positive.	Medium6	SortingBinary search+1	No attempts yet	1s	1024 MB	Judgeable
Sorting Numbers with Perfect SquaresGiven N integers up to 10^18, decide whether swapping pairs whose product is a perfect square can sort the array into non-decreasing order.	Medium6	Number theorySorting+1	No attempts yet	2.5s	1024 MB	Judgeable
FrogGiven jump lengths A and B and a limit X, count how many of the positions 1 cm to X cm to the right the frog can reach.	Medium6	MathNumber theory+1	No attempts yet	1s	512 MB	Judgeable
Mountain Climbing GameFind the minimum number of up and down actions to collect all N stones in order, then return to height 0, given energy E and peak height H.	Medium6	GreedySimulation+1	No attempts yet	2s	1024 MB	Judgeable
Transfer Station GameGiven a colored tree, count the vertices that lie on a path between two same-colored vertices for every color.	Medium6	TreeDFS+1	No attempts yet	2s	1024 MB	Judgeable
Interactive Treasure HuntFind two hidden treasure cells in an n by m grid with at most 7 DIG or SCAN operations, where SCAN returns the sum of Manhattan distances to both treasures.	Medium6	MathImplementation	No attempts yet	3s	512 MB	Judgeable
Eat More ApplesTwo students alternate moves on a 5x5 grid, eating apples and blocking cells they leave. Print 1 if the first student eats more under optimal play.	Medium6	Game theoryBit manipulation+1	No attempts yet	3s	512 MB	Judgeable
ABBCGiven a string of A, B, and C, find the maximum number of disjoint pairs, where each pair is an A before a B or a B before a C.	Medium6	GreedyString+1	No attempts yet	3s	1024 MB	Judgeable
Raspberry PieMove raspberries clockwise on a cycle of M pieces so each contestant's piece holds the raspberry they want, using the fewest moves, or print -1.	Medium6	GreedyArray+1	No attempts yet	2s	1024 MB	Judgeable
Special PrizeChoose M special-prize works so that the top K judge scores among the rest get main prizes, maximizing the sum of host scores over all winners.	Medium6	SortingGreedy+2	No attempts yet	2s	1024 MB	Judgeable
Connected Car ExperimentGiven N cars on a line with positions and fuel, find every car that can be connected to the IoT after car S is connected first.	Medium6	GraphBFS+1	No attempts yet	2s	1024 MB	Judgeable
Tree and QueriesFor each query, count the pairs of chosen vertices whose tree path uses only chosen vertices, given a tree with up to 250,000 vertices.	Medium6	TreeSorting+1	No attempts yet	3s	1024 MB	Judgeable
HomeworkGiven a min/max expression with N question marks, count the distinct values the expression can take when the marks are filled with a permutation of 1 to N.	Medium6	TreeDynamic programming	No attempts yet	1s	512 MB	Judgeable
Count of Integers Called Until the EndTwo players alternately call integers from a window of size k, avoiding forbidden values, and the task is to output the total number of calls under the win and lose rules.	Medium6	Dynamic programmingGame theory+1	No attempts yet	3s	512 MB	Judgeable
DigestaFind the shortest route from the start kernel to the end kernel where each link is strictly longer than the one before it, or print DIGESTA if no route exists.	Medium6	SortingGraph+2	No attempts yet	1s	512 MB	Judgeable
XOR GameGiven an array with point updates, answer range queries for the index whose XOR with x is smallest or largest, breaking ties by the smallest index.	Medium6	Segment treeTrie+1	No attempts yet	3s	512 MB	Judgeable
Rare InsectsGiven N insects with hidden types, find the sizes of the most frequent and rarest type groups using only same-type equality queries.	Medium6	ArrayBinary search+1	No attempts yet	2s	1024 MB	Judgeable
The MagicianGiven palindrome answers for some intervals of a hidden string of length N, decide whether its longest palindromic substring length is uniquely determined.	Medium6	StringDynamic programming+1	No attempts yet	30s	512 MB	Judgeable
VinjeteFor each city, find the size of the union of vignette intervals on the tree path from city 1 to it.	Medium6	TreeDFS+1	No attempts yet	3s	512 MB	Judgeable
SnagatorGiven M pairwise strength statements, find the first statement count after which at least K competitors can be fully ranked, or -1 if none.	Medium6	GraphTopological sort+1	No attempts yet	1s	1024 MB	Judgeable
Curious ShiftGiven two binary strings of length N, find the maximum number of positions where both strings have a 1 after cyclically shifting one of them.	Medium6	MathString matching	No attempts yet	1s	1024 MB	Judgeable
Točkice (Dot Game)Given N points with no three collinear, decide which player wins the game where both alternately draw non-crossing segments between the points.	Medium6	GeometryMath	No attempts yet	1s	1024 MB	Judgeable
NMABCDGiven an N by M grid and start and end cells, find the most cells a simple path from start to end can visit, moving up, down, left, or right.	Medium6	GraphMath+1	No attempts yet	1s	1024 MB	Judgeable
InversionsGiven a permutation of length N and M intervals [a, b], count the inversion pairs inside each interval.	Medium6	Sliding windowArray+1	No attempts yet	4s	1024 MB	Judgeable
PathsGiven a tree where each node's parent is a smaller divisor of it, count the paths of each length from 1 to N.	Medium6	TreeDFS+1	No attempts yet	1s	1024 MB	Judgeable
HilbertFor each pair X and Y, count the pairs of positive integers (a, b) whose product a times b is strictly less than X times Y.	Medium6	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
MANCEGiven a word, find the fewest MANCE statements needed to print it, where a loop repeats a block of print statements.	Medium6	Dynamic programmingString	No attempts yet	1s	1024 MB	Judgeable
WattGiven an array, handle range-assign updates and count the contiguous subarrays with an even sum inside a query interval.	Medium6	Segment treePrefix sum+1	No attempts yet	2s	1024 MB	Judgeable
Twinkle Twinkle 3Print the expected number of lit vertex and edge bulbs on a tree initially and after each vertex probability replacement.	Medium6	ProbabilityTree+1	No attempts yet	4s	1536 MB	Judgeable
Score of a SequenceGiven a sequence of up to 200,000 non-negative integers, the task is to sum min times max over all contiguous subarrays, modulo 1e9+7.	Medium6	SortingStack+2	No attempts yet	1s	1024 MB	Judgeable
Power Line ConnectionFind the minimum cost to connect pole 1 to pole N by removing some poles and linking the kept poles with power lines, where each line costs C_i - 2·gcd + C_j.	Medium6	Dynamic programmingMath+1	No attempts yet	1s	1024 MB	Judgeable
Optimal route and queriesGiven weighted bus routes between stops, answer each query with the minimum travel time from s to e using at most 3 buses, or -1 if impossible.	Medium6	Shortest pathGraph+1	No attempts yet	3s	1024 MB	Judgeable
SticksCount the pairs of red horizontal and blue vertical sticks that cross or touch, given up to 500000 sticks with coordinates up to 10^6.	Medium6	SortingSegment tree+1	No attempts yet	2s	1024 MB	Judgeable
PawnshopCut a word into consecutive pieces to maximize the total of C[k], where k is the number of distinct letters in each piece.	Medium6	Dynamic programmingSliding window	No attempts yet	3s	1024 MB	Judgeable
Audience QueueCount the ways to split a queue of n people into at most k nonempty contiguous sublines so that merging them by smallest head gives the target entrance order.	Medium6	Dynamic programmingSimulation	No attempts yet	1s	1024 MB	Judgeable
Make an XPick a center thumbtack, keep the longest valid chain in each of its four quadrants, and find the fewest thumbtacks to remove to form an X.	Medium6	SortingDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
MMSTFind a spanning tree whose weight is neither the minimum nor the maximum spanning tree weight, or report that none exists.	Medium6	GraphMinimum spanning tree+1	No attempts yet	1s	1024 MB	Judgeable
Tree MEXGiven a rooted tree with vertex values, print for each vertex the smallest non-negative integer missing from its subtree.	Medium6	TreeDFS+1	No attempts yet	2s	1024 MB	Judgeable
Phoenix StacksDecide whether a permutation can be sorted into ascending order using four stacks, where elements are pushed in order and then popped in any order.	Medium6	ArrayGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Number Guessing GameFor each game, compute the expected number of guesses under the given random midpoint strategy.	Medium6	Dynamic programmingProbability	No attempts yet	1s	1024 MB	Judgeable
PassFind an order of card values so the ball reaches every person exactly once, or print -1 if no such order exists.	Medium6	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
AND, OR, XORCount index pairs i<j whose AND, OR, or XOR equals K, for a sequence of up to 10^6 values each up to 10^6.	Medium6	Bit manipulationDynamic programming	No attempts yet	1s	1024 MB	Judgeable
GimbapPick intervals so that one chosen interval contains all the others, and find the maximum total of their values.	Medium6	SortingPrefix sum	No attempts yet	3s	1024 MB	Judgeable
FoldSimulate M folds on a roll of N towels and print the tallest stack, the towels touching the floor, and the towels visible from above.	Medium6	ArraySimulation+1	No attempts yet	2s	1024 MB	Judgeable
CircuitsFind the K-th lexicographically smallest Hamiltonian circuit from city 1 in a directed flight graph, or print 0 if fewer than K circuits exist.	Medium6	Dynamic programmingBit manipulation+1	No attempts yet	2s	1024 MB	Judgeable
Bipartite Graph GameAssign distinct weights to the nodes of a bipartite graph to maximize the total edge score, then find the best such score after deleting any single edge.	Medium6	SortingGreedy+1	No attempts yet	1s	512 MB	Judgeable
pqbdFind the length of the longest contiguous substring that is mirror symmetric or point symmetric under the given letter pairs, or report NOANSWER.	Medium6	StringString matching	No attempts yet	1s	512 MB	Judgeable