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Total results3,617 problems

JOI Park
Medium6
Shortest path, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Maximum Average Segment
Medium6
Binary search, Prefix sum
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
King of penalty
Medium6
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
16 MB
Judgeable
Apples and Bananas
Medium6
Dynamic programming, Prefix sum
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Safe Passage
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Zig Zag Nametag
Medium6
Greedy, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Uniting the Three Kingdoms
Medium6
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Addition Affliction
Medium6
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Red Rectangles
Medium6
Stack, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Farthest node in a weighted tree
Medium6
Tree, DFS
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Guessing Camels
Medium6
Segment tree, Sorting+1
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Schools
Medium6
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Multi-piano
Medium6
Hash map, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Closing the Farm
Medium6
Union-find, Graph
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
262144
Medium6
Dynamic programming, Intervals
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Splitting the Field
Medium6
Sorting, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Revenge of the Hot Dogs (Small)
Medium6
Binary search, Greedy+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Radio Receiver (Small)
Medium6
Binary search, Intervals+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Radio Receiver
Medium6
Binary search, Intervals+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Polygraph (Small)
Medium6
Brute force, Simulation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Football Team Photo
Medium6
Graph, Sorting+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Triangle Areas
Medium6
Geometry, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Don't be late
Medium6
Shortest path, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Junha at the Internet Lounge
Medium6
Sorting, Heap+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Binary string restoration
Medium6
String, Greedy+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
A Scary Part-Time Job
Medium6
Stack, Greedy
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mutalisk
Medium6
Dynamic programming, Brute force
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Playlist
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Royal Decree
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Stone Groups
Medium6
BFS, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Path Game
Medium6
Dynamic programming, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Equivalent Strings
Medium6
Divide and conquer, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Colorful Village
Medium6
Segment tree, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
A and B
Medium6
Greedy, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Favorite Array
Medium6
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Paths of length K
Medium6
Matrix, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Ordinary Knapsack 2
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Fun box packing
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Number Lock
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Time Travel and Multiset
Medium6
Dynamic programming, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Folding Paper
Medium6
Math, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Packing Balls
Medium6
Greedy, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Colorful Village 2
Medium6
Array, Binary search+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Happy Cow
Medium6
Dynamic programming, Intervals
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Candy Density
Medium6
Math, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Chain Detonation
Medium6
Greedy, Intervals+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Zeroes and Ones
Medium6
Math, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
History Cleanable DFA
Medium6
Graph, BFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
M and A
Medium6
Dynamic programming, String
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Model Railroad
Medium6
Minimum spanning tree, Union-find+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Happy Kindergarten
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Dice Game Win Probability
Medium6
Dynamic programming, Probability+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Domain clusters
Medium6
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Flipping Coins
Medium6
Probability, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Big Truck
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Brackets
Medium6
Greedy, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Nine Packs
Medium6
Dynamic programming
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
A Typo in Floyd
Medium6
Shortest path, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Railroad
Medium6
Sorting, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
The sun goes down...
Medium6
Geometry, Brute force+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Daydreaming Stockbroker
Medium6
Greedy, Simulation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Carrot Farm
Medium6
Intervals, Tree+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Minimum turns on the number screws
Medium6
Greedy, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
School Tour
Medium6
Minimum spanning tree, Union-find+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Array Sum
Medium6
Sorting, Hash map+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Marble Escape 2
Medium6
BFS, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jetpack
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Maximum XOR of two numbers
Medium6
Bit manipulation, Trie
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Number of good substrings
Medium6
String, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Elegant Showroom
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Flipping Coins 3
Medium6
Bit manipulation, Brute force+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Go--
Medium6
Prefix sum, Matrix+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mosaic tiles
Medium6
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Even Number of Tolls
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Spiral
Medium6
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Consistent Letter Path
Medium6
BFS, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cards
Medium6
Dynamic programming, Game theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lost in the Night
Medium6
Probability, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Parking Lot
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cash Book
Medium6
Dynamic programming, Backtracking+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Come and Go
Medium6
Graph, DFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
XOR Sum 3
Medium6
Bit manipulation, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tavan
Medium6
Combinatorics, Greedy+2
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
Windy Path
Medium6
Geometry, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Painting the fence
Medium6
Sorting, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Step Step Evolution
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Headstrong Student
Medium6
Math, Number theory+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Rock Man
Medium6
Graph, Greedy+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Marathon
Medium6
Stack, Simulation+2
No attempts yet
Time limit
0.2s
Memory limit
256 MB
Judgeable
Gold snack sticks on Cebu
Medium6
Graph, Union-find+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Exam Redistribution
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hamiltonian Hypercube
Medium6
Bit manipulation, Recursion+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Pohlepko
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Cameras
Medium6
Greedy, Sliding window+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hard Refactoring
Medium6
Intervals, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Large PhD Restaurant
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Longest Travel Route
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Phonomenal Reviews
Medium6
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Paths in Multigraph
Medium6
Graph, Minimum spanning tree+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bees
Medium6
Bit manipulation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
JOI ParkPick a distance X from square 1 to minimize C times X plus the total length of roads not fully inside the X radius.	Medium6	Shortest pathSorting+1	No attempts yet	1s	256 MB	Judgeable
Maximum Average SegmentFind the largest average over all contiguous subarrays of length at least K and print it truncated to six decimals.	Medium6	Binary searchPrefix sum	No attempts yet	1s	64 MB	Judgeable
King of penaltyPick the largest set of jobs that finishes before minute P, then order them longest first with idle waiting so the submission times sum to the maximum.	Medium6	GreedySorting	No attempts yet	1s	16 MB	Judgeable
Apples and BananasPick a path from the top left to the bottom right using right, down, and diagonal steps to maximize apples left below plus bananas left above.	Medium6	Dynamic programmingPrefix sum	No attempts yet	1s	256 MB	Judgeable
Safe PassageMove all students from the gate to the dorm alone or in pairs at the slower pace, with someone carrying the cloak back each time, in minimum total time.	Medium6	GreedySorting+1	No attempts yet	2s	256 MB	Judgeable
Zig Zag NametagGiven k, print the shortest lowercase string with adjacent letter differences summing to k, smallest alphabetically on ties.	Medium6	GreedyString+1	No attempts yet	1s	256 MB	Judgeable
Uniting the Three KingdomsFill the fewest sea cells so the three land groups on the grid join into one connected region.	Medium6	BFSGraph+1	No attempts yet	1s	256 MB	Judgeable
Addition AfflictionReorder each sum so numbers that pair to a multiple of 10 come first in adjacent pairs, using the most pairs and the smallest lexicographic order.	Medium6	GreedyMath+1	No attempts yet	1s	256 MB	Judgeable
Red RectanglesCount the subrectangles of an N by M red and blue grid that contain only red cells.	Medium6	StackDynamic programming+1	No attempts yet	1s	512 MB	Judgeable
Farthest node in a weighted treeFor every node of a weighted tree with up to 50000 nodes, print its distance to the farthest node.	Medium6	TreeDFS	No attempts yet	1s	256 MB	Judgeable
Guessing CamelsCount the camel pairs ranked in the same relative order in all three given bets.	Medium6	Segment treeSorting+1	No attempts yet	10s	512 MB	Judgeable
SchoolsChoose M cities for music schools and S other cities for sports schools to maximize the total number of attending students.	Medium6	GreedySorting	No attempts yet	2s	256 MB	Judgeable
Multi-pianoChoose a nonnegative step K so the walk that starts at the first pitch and moves by K on each rise or fall matches the true pitches in the most positions.	Medium6	Hash mapPrefix sum+1	No attempts yet	1s	64 MB	Judgeable
Closing the FarmAfter each barn closure in the given order, report whether the remaining open barns stay connected by open paths.	Medium6	Union-findGraph	No attempts yet	2s	512 MB	Judgeable
262144Merge adjacent equal numbers into a number one larger in any order to build the largest value possible.	Medium6	Dynamic programmingIntervals	No attempts yet	2s	512 MB	Judgeable
Splitting the FieldCompute how much fenced area is saved by covering all points with two disjoint axis-aligned rectangles instead of one.	Medium6	SortingPrefix sum+1	No attempts yet	2s	512 MB	Judgeable
Revenge of the Hot Dogs (Small)Vendors on a line move at speed 1 and must end at least D apart, so find the smallest time that allows such positions.	Medium6	Binary searchGreedy+1	No attempts yet	5s	512 MB	Judgeable
Radio Receiver (Small)Choose a walking path at speed at most one so every timed message on a line is within the smallest possible reception distance.	Medium6	Binary searchIntervals+1	No attempts yet	5s	512 MB	Judgeable
Radio ReceiverFind the smallest radius D that lets a person moving at speed one stay within D of each broadcast at its sending time.	Medium6	Binary searchIntervals+1	No attempts yet	5s	512 MB	Judgeable
Polygraph (Small)With at most 10 people, decide for each whether every satisfying assignment of truth-teller and liar types forces Truthtown, Liarville, or leaves it undecided.	Medium6	Brute forceSimulation+2	No attempts yet	5s	512 MB	Judgeable
Football Team PhotoEach player must differ in color from the next player to the right within one row of their row; find the minimum number of colors.	Medium6	GraphSorting+1	No attempts yet	5s	512 MB	Judgeable
Triangle AreasGiven N, M, A, find three lattice points in an N by M grid forming a triangle of area exactly A/2, printing the lexicographically smallest coordinate sequence or IMPOSSIBLE.	Medium6	GeometryMath+2	No attempts yet	5s	512 MB	Judgeable
Don't be lateGiven an undirected weighted graph with per-edge time and fare, find the minimum total fare of a path from node 1 to node N whose total time is at most T.	Medium6	Shortest pathGraph+2	No attempts yet	2s	128 MB	Judgeable
Junha at the Internet LoungeGiven N people each using a lounge over a fixed interval and always taking the lowest-numbered free seat, find the minimum number of seats so nobody waits, and the usage count of each seat.	Medium6	SortingHeap+2	No attempts yet	1s	128 MB	Judgeable
Binary string restorationGiven counts of each of the four adjacent pairs, build the lexicographically smallest binary string of length a+b+c+d+1 that realizes them, or report impossible.	Medium6	StringGreedy+2	No attempts yet	2s	256 MB	Judgeable
A Scary Part-Time JobGiven daily wages, choose a contiguous range maximizing (length of range) times (minimum wage in that range).	Medium6	StackGreedy	No attempts yet	1s	512 MB	Judgeable
MutaliskGiven the health of at most 3 SCVs, find the fewest attacks that deal 9, 3, 1 damage in some order to distinct SCVs and destroy them all.	Medium6	Dynamic programmingBrute force	No attempts yet	2s	512 MB	Judgeable
PlaylistCount length-P sequences over N songs where every song appears at least once and any two copies of the same song are separated by at least M other songs.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	2s	512 MB	Judgeable
Royal DecreeGiven a friendship graph and bound d, find the largest possible difference between richest and poorest that satisfies the friend-difference constraint, or -1 if unbounded.	Medium6	GraphShortest path+1	No attempts yet	2s	512 MB	Judgeable
Stone GroupsStarting from stone counts A, B, C, repeatedly double the smaller of two unequal groups and subtract it from the larger; decide whether all three can become equal.	Medium6	BFSMath+2	No attempts yet	2s	512 MB	Judgeable
Path GameGiven a 2 by M grid of white and black cells with a guaranteed left-right white path, find the maximum number of white cells that can be turned black while keeping some left-right path.	Medium6	Dynamic programmingGraph+2	No attempts yet	2s	512 MB	Judgeable
Equivalent StringsDecide whether two equal-length strings are equivalent under recursive splitting and optional swap of halves.	Medium6	Divide and conquerString+2	No attempts yet	2s	512 MB	Judgeable
Colorful VillageMaintain N houses under range repaint operations and answer queries counting how many of the T colors appear in a range.	Medium6	Segment treeBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
A and BGiven two strings of A and B, decide whether S can be turned into T using only: append A, or reverse then append B.	Medium6	GreedyString+2	No attempts yet	2s	512 MB	Judgeable
Favorite ArrayCount length-N arrays with entries from 1 to K where no earlier element is a larger multiple of the next.	Medium6	Dynamic programmingCombinatorics+1	No attempts yet	2s	512 MB	Judgeable
Paths of length KCount the number of length-K walks in a directed graph given its adjacency matrix, where K can be as large as 10^9, and output the count modulo 10^9+7.	Medium6	MatrixGraph+2	No attempts yet	2s	512 MB	Judgeable
Ordinary Knapsack 2Given N item types with weight, satisfaction, and a copy count, choose a multiset whose total weight is at most M and whose total satisfaction is largest.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	512 MB	Judgeable
Fun box packingGiven N box sizes, nest a box inside another when the outer size is at least twice the inner, each box holds at most one, and minimize the number of visible (unnested) boxes.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Number LockGiven two equal-length digit strings S and T, find the minimum number of turns where each turn adds 1 or subtracts 1 (mod 10) to every dial in some contiguous range.	Medium6	Dynamic programmingGreedy+2	No attempts yet	2s	512 MB	Judgeable
Time Travel and MultisetProcess insert, delete, and count operations on a time-indexed multiset, where each value's count at time t depends on prior operations with time at most t.	Medium6	Dynamic programmingBinary search+2	No attempts yet	2s	512 MB	Judgeable
Folding PaperStarting from a W by H sheet, each fold keeps the longer of the two pieces along one axis; find the minimum number of folds that yields area exactly A, or -1.	Medium6	MathGreedy+2	No attempts yet	2s	512 MB	Judgeable
Packing BallsGiven counts of red, green, and blue balls, pack them all into minimum boxes where each box holds 1 to 3 balls of one color or three distinct colors.	Medium6	GreedyMath+2	No attempts yet	2s	512 MB	Judgeable
Colorful Village 2For each query range in a nondecreasing brightness array, report how many times the most frequent value appears.	Medium6	ArrayBinary search+1	No attempts yet	2s	512 MB	Judgeable
Happy CowRemove portions from either end of a row over N days; on day d a portion with value H gives H times d. Maximize total happiness.	Medium6	Dynamic programmingIntervals	No attempts yet	2s	512 MB	Judgeable
Candy DensityChoose a candy density d minimizing the sum of \|W_i - d*C_i\|, and print the minimum as an exact reduced fraction.	Medium6	MathGreedy+2	No attempts yet	2s	512 MB	Judgeable
Chain DetonationPlace one extra bomb past the last one with unlimited power to destroy as many not-yet-detonated bombs, minimizing the duds among the original bombs.	Medium6	GreedyIntervals+1	No attempts yet	2s	512 MB	Judgeable
Zeroes and OnesInvert two adjacent characters of either of two binary strings to make them equal, using the fewest operations, or report -1.	Medium6	MathString+2	No attempts yet	2s	512 MB	Judgeable
History Cleanable DFAGiven a binary DFA, decide whether some input string drives every state to one common state.	Medium6	GraphBFS+1	No attempts yet	2s	512 MB	Judgeable
M and ADecide whether S can be interleaved character by character from a subsequence of S and a subsequence of T, both of the same length as S.	Medium6	Dynamic programmingString	No attempts yet	5s	512 MB	Judgeable
Model RailroadDecide if the existing tracks can be replaced, within the same total length budget, so that all stations become connected.	Medium6	Minimum spanning treeUnion-find+1	No attempts yet	2s	512 MB	Judgeable
Happy KindergartenSplit a non-decreasing array of heights into K contiguous groups to minimize the sum of each group's max-minus-min.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	512 MB	Judgeable
Dice Game Win ProbabilityA token moves on states 0 to N, stepping down with probability Q/P and up otherwise; find the probability of ending at N and print it modulo 1e9+7 as a reduced fraction.	Medium6	Dynamic programmingProbability+1	No attempts yet	1s	512 MB	Judgeable
Domain clustersGiven a directed graph of domains, find the size of the largest set in which every domain can reach every other domain.	Medium6	GraphDFS+2	No attempts yet	2s	512 MB	Judgeable
Flipping CoinsEach step flips a uniformly random set of A_i coins; find the expected number of heads after all K steps.	Medium6	ProbabilityDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
Big TruckFind a shortest path from node 1 to node n in an undirected weighted graph, and among all shortest paths maximize the total items collected at visited nodes.	Medium6	GraphShortest path+2	No attempts yet	2s	512 MB	Judgeable
BracketsGiven a bracket string, decide whether flipping the brackets in at most one contiguous segment can turn the whole string into a balanced, valid bracket sequence.	Medium6	GreedyPrefix sum+2	No attempts yet	2s	512 MB	Judgeable
Nine PacksGiven multiset pile sizes of hotdog and bun packs, buy the fewest total packs so the chosen hotdogs and buns sum to the same number.	Medium6	Dynamic programming	No attempts yet	2s	512 MB	Judgeable
A Typo in FloydCount ordered pairs whose shortest-path values differ when Floyd's outer loop skips vertex N as an intermediate.	Medium6	Shortest pathDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
RailroadGiven n intervals with distinct endpoint positions, find the maximum number of intervals fully contained in some segment of fixed length d.	Medium6	SortingSliding window+2	No attempts yet	1s	512 MB	Judgeable
The sun goes down...Given up to 100000 distinct points in the plane, decide whether two straight lines can cover all of them.	Medium6	GeometryBrute force+2	No attempts yet	5s	512 MB	Judgeable
Daydreaming StockbrokerGiven daily stock prices and a 100000 share cap, find the maximum money starting from $100 when whole shares can be bought and sold.	Medium6	GreedySimulation	No attempts yet	1s	512 MB	Judgeable
Carrot FarmMaintain a set of disjoint planted intervals under plant and harvest operations; after each, report the empty or planted area directly left and right of the affected span. Each area is (number of columns) times L.	Medium6	IntervalsTree+2	No attempts yet	3s	512 MB	Judgeable
Minimum turns on the number screwsEach left turn on a screw also rotates every screw below it; find the fewest total notches to reach the wanted digit string.	Medium6	GreedyMath	No attempts yet	1s	128 MB	Judgeable
School TourChoose a spanning tree of the graph rooted at the entrance that contains the fixed edge to building 1, find the min and max possible number of uphill edges among its edges, and print (max)^2 - (min)^2.	Medium6	Minimum spanning treeUnion-find+2	No attempts yet	1s	256 MB	Judgeable
Array SumReorder two arrays to make some sum value repeat as often as possible; report the maximum repeat count and the largest such sum.	Medium6	SortingHash map+1	No attempts yet	5s	512 MB	Judgeable
Marble Escape 2Find the minimum number of tilts that roll the red marble into the hole while the blue marble never falls in.	Medium6	BFSSimulation+1	No attempts yet	2s	512 MB	Judgeable
JetpackFind the lexicographically smallest schedule of screen holds that moves Barry right across N columns through a 10-row grid while avoiding obstacles.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	64 MB	Judgeable
Maximum XOR of two numbersGiven N non-negative integers, find the maximum XOR over all pairs of distinct elements.	Medium6	Bit manipulationTrie	No attempts yet	2s	512 MB	Judgeable
Number of good substringsCount how many distinct substrings of s contain at most k bad letters, counting equal substrings once.	Medium6	StringHash map+1	No attempts yet	2s	512 MB	Judgeable
Elegant ShowroomA car on a grid needs a path to a border door; every car cell on the path must be moved, so find the path with the fewest car cells.	Medium6	GraphShortest path+2	No attempts yet	2s	512 MB	Judgeable
Flipping Coins 3Flip whole rows or columns of an N by M grid of coins to leave as few tails as possible, with N at most 20.	Medium6	Bit manipulationBrute force+1	No attempts yet	5s	512 MB	Judgeable
Go--Given a board with black and white stones, count the square sub-areas that contain stones of only one color and report the two totals.	Medium6	Prefix sumMatrix+1	No attempts yet	1s	512 MB	Judgeable
Mosaic tilesGiven an H by L grid with holes (0), fill every hole with one chosen color so that the smallest connected monochromatic region is as large as possible, and report that size.	Medium6	GraphUnion-find+2	No attempts yet	1s	512 MB	Judgeable
Even Number of TollsFind the cheapest walk from city 1 to city C in a weighted undirected graph where the number of edges traversed (tolls paid) must be even, counting repeated edges each time.	Medium6	GraphShortest path+2	No attempts yet	1s	512 MB	Judgeable
SpiralPlace B beans in a clockwise inward spiral on an N by N board and report the row and column of the B-th bean.	Medium6	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Consistent Letter PathFind the shortest path on an N by N letter grid from top-left to bottom-right where no letter appears in both lowercase and uppercase along the path.	Medium6	BFSBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
CardsGiven an even row of cards with integers, two players alternately take an end card; the first player maximizes his total sum while the second minimizes it. Report the best score the first player can guarantee.	Medium6	Dynamic programmingGame theory+2	No attempts yet	2s	512 MB	Judgeable
Lost in the NightOn a tree, a walker starting at node A repeatedly picks a uniformly random neighbor until reaching hotel B or C; find the probability of hitting B first.	Medium6	ProbabilityGraph+2	No attempts yet	2s	512 MB	Judgeable
Parking LotSimulate a single-line parking lot where each arriving vehicle takes the first free gap from the entrance that fits, and total the fees for vehicles that park.	Medium6	SimulationImplementation+2	No attempts yet	2s	512 MB	Judgeable
Cash BookGiven N amounts and a signed total F, decide for each amount whether it is forced to be added, forced to be subtracted, or free, over all sign choices summing to F.	Medium6	Dynamic programmingBacktracking+2	No attempts yet	2s	512 MB	Judgeable
Come and GoGiven a mixed graph of one-way and two-way streets, decide whether every pair of intersections is mutually reachable.	Medium6	GraphDFS+1	No attempts yet	2s	512 MB	Judgeable
XOR Sum 3Compute the XOR of every contiguous subsequence of A and print the sum of all those XOR values.	Medium6	Bit manipulationPrefix sum+1	No attempts yet	2s	512 MB	Judgeable
TavanGiven a pattern with # placeholders, each replaced by one of K given letters, find the Xth resulting string in alphabetical order.	Medium6	CombinatoricsGreedy+2	No attempts yet	1s	32 MB	Judgeable
Windy PathGiven N points and a string of L/R turns, build the non-crossing path by repeatedly picking the unused point that is extreme (leftmost or rightmost) relative to the last point.	Medium6	GeometryGreedy+2	No attempts yet	2s	512 MB	Judgeable
Painting the fencePick a pairwise non-overlapping set of intervals to cover as many of the n slats as possible, then report the number left unpainted.	Medium6	SortingDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Step Step EvolutionGiven a sequence of dance-pad arrows, find the minimum number of adjacent pairs pressed by the same foot, respecting the left/right column rule.	Medium6	Dynamic programmingGreedy+2	No attempts yet	8s	512 MB	Judgeable
Headstrong StudentFor each fraction x/y, report how many decimal digits come before the repeating part starts and how long that repeating part is (0 if the decimal terminates).	Medium6	MathNumber theory+2	No attempts yet	8s	512 MB	Judgeable
Rock ManEach tool takes day1 days normally or day2 if its support tool is finished first; order the tools to minimize total days.	Medium6	GraphGreedy+2	No attempts yet	8s	512 MB	Judgeable
MarathonGroups at distinct coordinates move right at speed 100/size and merge on contact; simulate until stable and report final sizes left to right.	Medium6	StackSimulation+2	No attempts yet	0.2s	256 MB	Judgeable
Gold snack sticks on CebuGiven a weighted undirected graph, find the maximum over all routes from s to e of the minimum edge weight on the route.	Medium6	GraphUnion-find+1	No attempts yet	1s	256 MB	Judgeable
Exam RedistributionFind the lexicographically smallest order to visit rooms so the exam pile never runs out and no room 1 student can end up with their own exam.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Hamiltonian HypercubeGiven two binary strings in Gray Code order, count how many code words lie strictly between them on the n-bit Gray Code path.	Medium6	Bit manipulationRecursion+1	No attempts yet	2s	512 MB	Judgeable
PohlepkoFind the lexicographically smallest string read along a monotone path from the top-left to the bottom-right cell of a grid of lowercase letters.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	64 MB	Judgeable
CamerasGiven houses that already have cameras, add the minimum number of cameras so every window of r consecutive houses holds at least two cameras.	Medium6	GreedySliding window+1	No attempts yet	1s	512 MB	Judgeable
Hard RefactoringMerge a union of integer intervals given as comparisons, then reprint the merged ranges using the fewest possible constants, with special handling for saturated ends and all-true or all-false cases.	Medium6	IntervalsSorting+2	No attempts yet	2s	512 MB	Judgeable
Large PhD RestaurantGiven N tasks each with a cost and a reward, and starting money M, choose an order to run tasks (paying cost first, then gaining reward) that maximizes the final money.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
The Longest Travel RouteGiven a directed weighted graph with at most 18 cities, find the maximum total length of a simple path from city 0 to city n-1.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Phonomenal ReviewsGiven a tree and a set of M marked nodes, find the minimum number of edges Jo must walk to visit every marked node, starting anywhere.	Medium6	TreeDFS+2	No attempts yet	2s	512 MB	Judgeable
Paths in MultigraphFind the minimum number of edges to delete from an undirected multigraph so the remaining graph becomes disconnected.	Medium6	GraphMinimum spanning tree+1	No attempts yet	2s	512 MB	Judgeable
BeesGiven an n by m hexagonal honeycomb's initial honey pattern, apply the rule that each cell fills next day exactly when an odd number of its neighbors were filled, and print the state after k days.	Medium6	Bit manipulationSimulation+2	No attempts yet	1s	512 MB	Judgeable