Problems

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Total results29,458 problems

Toll Roads
Medium4
Union-find, Minimum spanning tree+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Matrix
Medium4
Hash map, Prefix sum
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Padovan Sequence 2
Medium4
Matrix, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stop Saying That Flag Line
Medium4
Greedy, Prefix sum
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Love Revolution
Medium4
Minimum spanning tree, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Coin Collecting 2
Medium4
Math, Brute force+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Vrsta
Medium4
Segment tree, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Creative Accounting
Medium4
Prefix sum, Brute force+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Everything Is A Nail
Medium4
Dynamic programming, Implementation
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Beppa and SwerChat
Medium4
Greedy, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Controllers
Medium4
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Pea Pattern
Medium4
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Road To Savings
Medium4
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Simple Solitaire
Medium4
Simulation, Stack
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Konstrukcija Special Judge
Medium4
Implementation, Graph
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Qizz Quzz (Easy)
Medium4
Implementation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Queue Skipping (Hard)
Medium4
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Solitaire
Medium4
Simulation, Implementation
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Town
Medium4
Math, Binary search+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Two covers
Medium4
Array, Prefix sum+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Boredom Buster (Hard)
Medium4
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gems in the maze
Medium4
Graph, DFS+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Easy representation
Medium4
String, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Adding the Exponents
Medium4
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Manhattan Crepe Cart
Medium4
Matrix, Prefix sum+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Nesting Depth
Medium4
Greedy, String+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Parenting Partnering Returns
Medium4
Greedy, Sorting+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Anti-Blot System
Medium4
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Paradox With Averages
Medium4
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Biased Standings
Medium4
Sorting, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stamp Grid
Medium4
Brute force, Matrix+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Counting Pythagorean Triples
Medium4
Number theory, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Caravan Trip Plans
Medium4
Dynamic programming, Array
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
aFan Event Planning
Medium4
Prefix sum, Binary search
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Gahee and Chords
Medium4
Implementation, Hash map+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Gold Mine
Medium4
Tree, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Shoulder Buddy
Medium4
Binary search, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Picking Hyper Branches
Medium4
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dancing Eggplant
Medium4
Simulation, Greedy+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Shooting Practice
Medium4
Brute force, Simulation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
The score is just a helper
Medium4
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Treasure Hunt 2
Medium4
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mentoring Matching
Medium4
Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Clear the Game
Medium4
Dynamic programming, Greedy
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Horse Race
Medium4
Topological sort, Graph+1
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
I Love Geometry
Medium4
Brute force, Geometry+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Conveyor Belt Sushi
Medium4
Array, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Safe Construction Plan
Medium4
Graph, Union-find
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Number Tower and Queries
Medium4
Binary search, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Interesting Modulo Operation
Medium4
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Another Goose Goose Duck Problem
Medium4
Math, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Shelters
Medium4
Brute force, Implementation
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Grid Game
Medium4
Dynamic programming, Game theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Iranian Hazfi Cup
Medium4
Tree, Hash map+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bullet Marks to Numbers
Medium4
Stack, Tree
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Study Cafe
Medium4
Sorting, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Redstone
Medium4
BFS, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fractal
Medium4
Math, Geometry
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
More Common Tile Coloring
Medium4
Array, Implementation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Magnet
Medium4
Array, Dynamic programming
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
CCC Word Hunt
Medium4
Brute force, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Symmetric Mountains
Medium4
Brute force, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
White Collar
Medium4
Shortest path, BFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Distributing Candy
Medium4
Binary search, Sorting
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Metro Construction
Medium4
Binary search, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Composite Functions for the Chairman
Medium4
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Multiplication and Queries
Medium4
Hash map, Math
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Game
Medium4
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tricknology
Medium4
Number theory, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Avoiding Multiples
Medium4
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sketch
Medium4
Implementation, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Artifacts (Basic)
Medium4
Tree, BFS
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Rick's Robe (Basic)
Medium4
Graph, BFS
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Faction Standoff
Medium4
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
We need fewer roads!
Medium4
Union-find, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Interval
Medium4
Intervals, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Component Chemistry
Medium4
Hash map, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Magic Clock (Basic)
Medium4
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
An Important Scientific Number
Medium4
Number theory, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Big Trampoline
Medium4
Brute force, Geometry
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Coins
Medium4
Simulation, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Lemur Parties (Prime)
Medium4
Math, Combinatorics
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Black and White
Medium4
Math, Number theory
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Defusing the Bomb
Medium4
Hash map, Greedy
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
It
Medium4
Sliding window, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Maleficent Sum
Medium4
Prefix sum, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Fibonacci Squares
Medium4
Math, Recursion
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Jerry's Trap
Medium4
Sorting, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Commemorative Photos
Medium4
Sorting, Dynamic programming
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Headshot
Medium4
Greedy, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Archery Club
Medium4
Greedy, Simulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Chariot Race
Medium4
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
String Game
Medium4
Sliding window, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Household Errands
Medium4
Brute force, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Going Home
Medium4
Greedy, Bit manipulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sea Battle
Medium4
Math, Binary search
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Great Comebacks
Medium4
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Breaking into the Reliquary
Medium4
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Non-decreasing array
Medium4
Greedy, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Gift for Luigi
Medium4
Sorting, Greedy
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Toll RoadsFor each city pair, find the lowest possible maximum toll on a route between them and the number of cities reachable from the first city under that toll.	Medium4	Union-findMinimum spanning tree+1	No attempts yet	3s	1024 MB	Judgeable
MatrixSupport range +1 updates on single rows and point queries on an N by M matrix with N, M up to 1e18, handled online.	Medium4	Hash mapPrefix sum	No attempts yet	1.5s	1024 MB	Judgeable
Padovan Sequence 2Given N up to 10^18, compute P(N) modulo 998244353, where each term is the sum of the terms two and three positions before it.	Medium4	MatrixDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Stop Saying That Flag LineFind the fewest shouts, each adding a boost that shrinks with distance from the shouter's spot, so every minion reaches its target strength.	Medium4	GreedyPrefix sum	No attempts yet	1s	1024 MB	Judgeable
Love RevolutionRemove the cheapest set of unestablished relationships so that no cycle remains, keeping all established ones, and report the minimum total affection lost.	Medium4	Minimum spanning treeGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Coin Collecting 2Aoi flips one row and Rin flips one column, each trying to collect more coins. Find both players' counts under optimal play.	Medium4	MathBrute force+1	No attempts yet	2s	1024 MB	Judgeable
VrstaAfter each statement adds a_i students of height v_i, output the height of the middle student, choosing the shorter one when the count is even.	Medium4	Segment treeSorting+1	No attempts yet	1s	1024 MB	Judgeable
Creative AccountingGiven daily profits and a range of segment sizes, find the minimum and maximum count of profitable segments over all sizes and starting days.	Medium4	Prefix sumBrute force+1	No attempts yet	5s	1024 MB	Judgeable
Everything Is A NailGiven a sequence of nail, screw, and bolt tasks, find the most tasks you can complete when switching tools permanently loses the old one.	Medium4	Dynamic programmingImplementation	No attempts yet	5s	1024 MB	Judgeable
Beppa and SwerChatGiven two recorded orderings of n members, find the minimum number of members who must have gone online between the two snapshots.	Medium4	GreedyTwo pointers+1	No attempts yet	2s	1024 MB	Judgeable
ControllersGiven a string of + and - round symbols, decide for each pair of button values whether pressing one button per round can bring the final score to exactly 0.	Medium4	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Pea PatternGiven a start number and a target, generate the look-and-say style sequence (digits with no occurrences are skipped) and report the target's 1-based position, or whether it never appears within 100 terms.	Medium4	StringSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Road To SavingsGiven a road network, find the total length of roads that lie on no shortest path between the mayor's house a and office b.	Medium4	Shortest pathGraph	No attempts yet	1s	1024 MB	Judgeable
Simple SolitaireSimulate a solitaire game where each turned-over card is compared with the card three positions earlier, and report the cards left after all cascades.	Medium4	SimulationStack	No attempts yet	1s	1024 MB	Judgeable
Konstrukcija Special JudgeGiven the output of problem 19232 as input, print the original input of that problem, namely tns(1, N) of the graph.	Medium4	ImplementationGraph	No attempts yet	1s	1024 MB	Judgeable
Qizz Quzz (Easy)Given label sequences, find the longest prefix that a Fizz Buzz variant with at most two rules, each string of length 4, could have produced.	Medium4	ImplementationBrute force+1	No attempts yet	1s	1024 MB	Judgeable
Queue Skipping (Hard)Given the order in which people skip to the front of a queue, find the person who is last in line when the store opens.	Medium4	ArrayImplementation	No attempts yet	2s	1024 MB	Judgeable
SolitaireGiven a shuffled deck of 4n cards across four suits, count how many passes through the deck are needed to place every card on its suit slot.	Medium4	SimulationImplementation	No attempts yet	3s	1024 MB	Judgeable
TownGiven how many of each digit 0 to 9 you have, find the largest x such that the numbers 1 through x can all be written with those digits.	Medium4	MathBinary search+1	No attempts yet	1s	1024 MB	Judgeable
Two coversCount positions x that lack both a piece reaching k letters left of x and a different piece reaching k letters right of x.	Medium4	ArrayPrefix sum+1	No attempts yet	3s	1024 MB	Judgeable
Boredom Buster (Hard)Split an integer into two parts until n ones remain, earning the product of the parts at each split. Find the maximum hazelnuts.	Medium4	MathCombinatorics	No attempts yet	1s	1024 MB	Judgeable
Gems in the mazeFind the longest run of distinct chambers reachable by repeatedly following the tunnel from v to (av^2 + bv + c) mod n.	Medium4	GraphDFS+1	No attempts yet	3s	2048 MB	Judgeable
Easy representationGiven a correct bracket sequence, find the area of the black regions in its geometric representation, where regions alternate colors starting with black outside.	Medium4	StringMath	No attempts yet	1s	1024 MB	Judgeable
Adding the ExponentsGiven N distinct primes and K up to 10^12, find the sum over i from 1 to K of how many times the primes in P divide i, counted with multiplicity.	Medium4	Number theoryMath	No attempts yet	1s	128 MB	Judgeable
Manhattan Crepe CartGiven people on a grid, each with a position and compass direction, find the intersection that the most people are heading toward, breaking ties by smallest x then smallest y.	Medium4	MatrixPrefix sum+1	No attempts yet	20s	1024 MB	Judgeable
Nesting DepthGiven a digit string, insert the fewest parentheses so each digit equals its nesting depth and every parenthesis is matched.	Medium4	GreedyString+1	No attempts yet	20s	1024 MB	Judgeable
Parenting Partnering ReturnsAssign each activity time interval to one of two people so that no person has overlapping intervals, or report IMPOSSIBLE if that cannot be done.	Medium4	GreedySorting+1	No attempts yet	20s	1024 MB	Judgeable
Anti-Blot SystemGiven an addition equation where one part is replaced by the string machula, fill in the missing digits to recover the full equation.	Medium4	ImplementationString+1	No attempts yet	1s	1024 MB	Judgeable
Paradox With AveragesCount the Computer Science students whose departure raises the CS average and whose arrival raises the Economics average.	Medium4	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Biased StandingsGiven N teams with preferred places, assign each team a distinct place from 1 to N so the sum of absolute differences is minimal, and print that minimum.	Medium4	SortingGreedy	No attempts yet	1s	1024 MB	Judgeable
Stamp GridDecide whether a K x K stamp, rotated as needed, can be placed on an empty N x N canvas to match a target pattern without inking any blank cell.	Medium4	Brute forceMatrix+1	No attempts yet	2s	1024 MB	Judgeable
Counting Pythagorean TriplesGiven n, count the primitive and non-primitive Pythagorean triples where n is the hypotenuse and where n is a leg.	Medium4	Number theoryMath+1	No attempts yet	2s	1024 MB	Judgeable
Caravan Trip PlansCount the distinct day-by-day camp sequences that start at camp 0, never move backward, and reach a given oasis on a given day.	Medium4	Dynamic programmingArray	No attempts yet	5s	1024 MB	Judgeable
aFan Event PlanningGiven daily token gains, process reset boundaries and, for each query, report the token sum from the last reset inside the range up to day e.	Medium4	Prefix sumBinary search	No attempts yet	2s	1024 MB	Judgeable
Gahee and ChordsGiven measures of notes, pick one chord per measure by counting note names while skipping chords used k or more times in the previous p measures.	Medium4	ImplementationHash map+1	No attempts yet	1.5s	1024 MB	Judgeable
Gold MineGiven a rooted tree, find the fewest groups of rooms so that any two rooms in the same group are at odd distance from each other.	Medium4	TreeMath	No attempts yet	2s	1024 MB	Judgeable
Shoulder BuddyFind the smallest H so that at most k students have a height gap greater than H with at least one neighbor.	Medium4	Binary searchArray	No attempts yet	1s	1024 MB	Judgeable
Picking Hyper BranchesGiven 2047 of the 2048 corners of an 11-dimensional box, find the one corner that is missing.	Medium4	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Dancing EggplantSimulate a branch that starts in the center 2x2 block and grows one row or column per step toward the direction with the largest nutrient sum, then report the total and the moves.	Medium4	SimulationGreedy+1	No attempts yet	2s	1024 MB	Judgeable
Shooting PracticeGiven an N by N board and K bullets, find the maximum score by choosing a row for each shot, where a destroyed target spawns smaller neighbors.	Medium4	Brute forceSimulation+1	No attempts yet	1s	512 MB	Judgeable
The score is just a helperGiven pitches in playing order, find the minimum N so that consecutive notes can be numbered from 1 to N while keeping each up, down, or equal relation.	Medium4	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Treasure Hunt 2Find the minimum fuel for a ship to reach the treasure on a grid, where moves to the three cells in the next column are free and all other moves cost 1.	Medium4	GraphShortest path+2	No attempts yet	1s	512 MB	Judgeable
Mentoring MatchingGiven each Hangwayeong student's ranking of KAIST students and a fixed KAIST preference by number distance, find a stable one-to-one matching.	Medium4	Greedy	No attempts yet	1s	1024 MB	Judgeable
Clear the GamePick one weapon per run so that consecutive runs never share a weapon, minimizing the total clear time over N runs.	Medium4	Dynamic programmingGreedy	No attempts yet	1s	512 MB	Judgeable
Horse RaceGiven the placement of each small race's winner, the task is to output one full-race finishing order that satisfies every winner constraint.	Medium4	Topological sortGraph+1	No attempts yet	0.1s	1024 MB	Judgeable
I Love GeometryCount the non-degenerate triangles with lattice-point vertices in an N by M yard, where triangles that match after rotation or reflection count once.	Medium4	Brute forceGeometry+1	No attempts yet	3s	1024 MB	Judgeable
Conveyor Belt SushiCount how many sushi pieces each customer eats, given each customer's wish list and the order the pieces pass down the belt.	Medium4	ArraySimulation	No attempts yet	1s	1024 MB	Judgeable
Safe Construction PlanGiven N columns and M existing beams, find the minimum total cost of triangle jobs that connect every pair of columns.	Medium4	GraphUnion-find	No attempts yet	2s	1024 MB	Judgeable
Number Tower and QueriesGiven a, d, and x, find the floor holding block number x and its position from the left on that floor, where floor i has a + (i-1)d blocks.	Medium4	Binary searchMath	No attempts yet	2s	1024 MB	Judgeable
Interesting Modulo OperationGiven N and R, find the sum of all positive integers m for which N mod m equals R.	Medium4	MathNumber theory	No attempts yet	1s	1024 MB	Judgeable
Another Goose Goose Duck ProblemChoose an integer cooldown a in [l, r] and find the minimum time to kill k geese that arrive every b seconds.	Medium4	MathGreedy	No attempts yet	1s	1024 MB	Judgeable
SheltersPick K of the N houses as shelters to minimize the largest Manhattan distance from any house to its nearest shelter.	Medium4	Brute forceImplementation	No attempts yet	3s	1024 MB	Judgeable
Grid GameFor each start cell on a grid with blocked cells, decide the winner of a game that moves a piece to the bottom-right corner with down, right, or diagonal moves of up to K cells.	Medium4	Dynamic programmingGame theory	No attempts yet	1s	1024 MB	Judgeable
Iranian Hazfi CupGiven the results of a knockout tournament in arbitrary order, find the round in which two queried teams could first meet, with penalty shootouts deciding winners.	Medium4	TreeHash map+1	No attempts yet	2s	1024 MB	Judgeable
Bullet Marks to NumbersGiven the DFS preorder levels of a tree's items, print each item's sibling index, or -1 if no tree matches the levels.	Medium4	StackTree	No attempts yet	2s	1024 MB	Judgeable
Study CafeGiven seat fees and customer stay intervals, find the minimum and maximum total revenue when each day every active customer takes a distinct seat.	Medium4	SortingPrefix sum+1	No attempts yet	2s	1024 MB	Judgeable
RedstoneGiven a grid of redstone dust, redstone blocks, and lamps, decide whether every lamp can be lit at the same moment as signals spread outward.	Medium4	BFSMatrix+1	No attempts yet	1s	1024 MB	Judgeable
FractalGiven N and a, the task is to find the perimeter of the N-gon fractal built until the side reaches 1, modulo 1000000007.	Medium4	MathGeometry	No attempts yet	1s	1024 MB	Judgeable
More Common Tile ColoringGiven an N by M letter grid, find the fewest cells to repaint so every K by K block matches one shared K by K pattern, and print the result.	Medium4	ArrayImplementation+1	No attempts yet	2s	1024 MB	Judgeable
MagnetPick two different cells for the N and S poles to maximize a_i minus a_j minus K times the distance between them.	Medium4	ArrayDynamic programming	No attempts yet	2s	1024 MB	Judgeable
CCC Word HuntCount how many ways a word can be hidden in a letter grid, either along one straight line or along two segments that meet at a right angle.	Medium4	Brute forceMatrix+1	No attempts yet	1s	1024 MB	Judgeable
Symmetric MountainsFor each crop length, finds the minimum sum of height differences between mirrored mountain pairs over all consecutive crops of that length.	Medium4	Brute forceArray	No attempts yet	1s	1024 MB	Judgeable
White CollarGiven a map of one-way roads, list every city that lies on some shortest path from city 1 to city N.	Medium4	Shortest pathBFS+1	No attempts yet	1s	1024 MB	Judgeable
Distributing CandyFind the smallest non-negative X so that the sum of (A_i - X) over all scores above X does not exceed K.	Medium4	Binary searchSorting	No attempts yet	2s	1024 MB	Judgeable
Metro ConstructionFind the smallest integer voltage x so that the total power of n two-mode engines reaches at least p.	Medium4	Binary searchMath	No attempts yet	1s	1024 MB	Judgeable
Composite Functions for the ChairmanGiven an integer quadratic f and a linear g, count the x-values where f(g(x)) equals g(f(x)) and report the matching phrase.	Medium4	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Multiplication and QueriesGiven a sequence where some elements are set to zero, answer whether two different elements multiply to x for each query.	Medium4	Hash mapMath	No attempts yet	1.5s	1024 MB	Judgeable
GameSum g(N) for every N from L to R, where g is 1 if repeatedly applying f reaches a fixed point, 0 if it never does, and -1 if a value exceeds 100000.	Medium4	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
TricknologyFor each query L R, count pairs x < y within [L, R] where the sum of all integers from x to y is prime.	Medium4	Number theoryPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Avoiding MultiplesCount subsets of size two or more where no two elements sum to a multiple of K, modulo 1,000,000,007.	Medium4	CombinatoricsMath+1	No attempts yet	1s	1024 MB	Judgeable
SketchDecide whether a grid of red and white pixels can be painted using only circle and cross brushes that may extend past the edge.	Medium4	ImplementationBrute force	No attempts yet	1s	1024 MB	Judgeable
Artifacts (Basic)Given a tree where each site holds artifact kind 0, 1, or 2, find the shortest walk that collects every required kind, or print -1 if one is missing.	Medium4	TreeBFS	No attempts yet	1.5s	1024 MB	Judgeable
Rick's Robe (Basic)Given an undirected graph with soaked vertices and hole vertices, find the maximum over soaked vertices of the distance to the nearest hole.	Medium4	GraphBFS	No attempts yet	1s	1024 MB	Judgeable
Faction StandoffGiven each city's faction and which cities can be flipped, find the fewest flips so that every road joins two cities of different factions, or -1 if impossible.	Medium4	GraphBFS+1	No attempts yet	1s	1024 MB	Judgeable
We need fewer roads!Given n houses and m roads, delete the fewest non-essential roads so no cycle remains, keeping every must-keep road, or report NO if impossible.	Medium4	Union-findGreedy+1	No attempts yet	1s	1024 MB	Judgeable
IntervalGiven two lists of natural number intervals with open or closed ends, find the sum of numbers in the first list that are missing from the second.	Medium4	IntervalsSorting+1	No attempts yet	1s	1024 MB	Judgeable
Component ChemistryAfter each add or remove query, print how many pairs of current components have efficiencies whose sum is divisible by m.	Medium4	Hash mapMath	No attempts yet	1s	1024 MB	Judgeable
Magic Clock (Basic)Given a 720-division clock whose minute hand teleports to 0 when it catches the hour hand, find the minutes needed to go from one state to another, or -1 if unreachable.	Medium4	SimulationImplementation	No attempts yet	2s	1024 MB	Judgeable
An Important Scientific NumberGiven gear sizes a and b, find the smallest non-negative x so that b divides a+x and a divides b+x.	Medium4	Number theoryMath	No attempts yet	2s	1024 MB	Judgeable
Big TrampolineGiven n points, find the vertex order that gives a simple polygon of maximum area, or report No when all points are collinear.	Medium4	Brute forceGeometry	No attempts yet	2s	1024 MB	Judgeable
CoinsCount the moves until no coins are heads up, where each move flips coin k and k is the current heads count, or print -1 if the game never ends.	Medium4	SimulationDynamic programming	No attempts yet	1s	1024 MB	Judgeable
Lemur Parties (Prime)Count the distinct multisets of n lemurs from k species, where each species contributes at most two lemurs, modulo 1000000007.	Medium4	MathCombinatorics	No attempts yet	2s	1024 MB	Judgeable
Black and WhiteGiven n turns up to 10^18, output the irreducible fraction for the probability that Alex never guesses the black-with-white zebra.	Medium4	MathNumber theory	No attempts yet	2s	1024 MB	Judgeable
Defusing the BombGiven n button values and a target k, find the fewest buttons to deactivate so that no two active values sum to k.	Medium4	Hash mapGreedy	No attempts yet	2s	1024 MB	Judgeable
ItCount the substrings of s whose letter counts do not exceed the letter counts of t, using each letter of t at most once.	Medium4	Sliding windowTwo pointers+1	No attempts yet	2s	1024 MB	Judgeable
Maleficent SumGiven n nonnegative integers, compute the sum of a_i * a_j * a_k over all index triples i < j < k, modulo 1000000007.	Medium4	Prefix sumMath+1	No attempts yet	2s	1024 MB	Judgeable
Fibonacci SquaresGiven n up to 10^18, compute the sum of squares of f_0 through f_n for the sequence with f_0 = f_1 = 1, modulo 998244353.	Medium4	MathRecursion	No attempts yet	2s	1024 MB	Judgeable
Jerry's TrapGiven platform heights, after each uniform shift x, print the sum of absolute values of all heights, with shifts accumulating.	Medium4	SortingPrefix sum+1	No attempts yet	2s	1024 MB	Judgeable
Commemorative PhotosSplit heights into the fewest groups of up to three, where a triple spans at most 10 cm and a pair at most 20 cm.	Medium4	SortingDynamic programming	No attempts yet	2s	1024 MB	Judgeable
HeadshotGiven n shots, magazine size m, full reload time a, and per-round load time b, find the minimum total time to fire exactly n shots.	Medium4	GreedyMath	No attempts yet	2s	1024 MB	Judgeable
Archery ClubGiven students on a line, each with a bow range and power, find the fewest students to order to shoot so that the chain of hits makes everyone shoot.	Medium4	GreedySimulation	No attempts yet	2s	1024 MB	Judgeable
Chariot RaceSplit n coins into a bet on victory and the rest on defeat so Kratos profits in both outcomes, and list the splits with the largest winnings.	Medium4	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
String GameCheck whether some substring of s of length k has letter counts that t can supply using k of its characters in any order.	Medium4	Sliding windowString+1	No attempts yet	2s	1024 MB	Judgeable
Household ErrandsFind the minimum time for Miles to buy groceries at the store, pick up a package at the post office, and walk home over three roads.	Medium4	Brute forceGraph+1	No attempts yet	2s	1024 MB	Judgeable
Going HomeGiven buttons that OR-combine with the current universe number, find at most 100 presses that turn universe A into B, or report -1 if impossible.	Medium4	GreedyBit manipulation	No attempts yet	2s	1024 MB	Judgeable
Sea BattleFind the largest k such that one ship of size k, two of size k-1, up to k ships of size 1 fit non-touching on a 1 x n field.	Medium4	MathBinary search	No attempts yet	2s	1024 MB	Judgeable
Great ComebacksGiven the final powerful strike counts of Thor and Hulk, find the largest possible number of times a trailing fighter goes on to lead.	Medium4	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Breaking into the ReliquaryGiven a sequence where each value may be off by at most 1, decide whether it could be a cyclic shift of 1 to n, and output a possible position of 1.	Medium4	ArrayImplementation	No attempts yet	2s	1024 MB	Judgeable
Non-decreasing arrayEach element may be negated; decide the signs so the array becomes non-decreasing, or report that it is impossible.	Medium4	GreedyArray	No attempts yet	2s	1024 MB	Judgeable
Gift for LuigiGiven four stick lengths, find the two side lengths of the largest-area rectangle that can be cut from the sticks.	Medium4	SortingGreedy	No attempts yet	2s	1024 MB	Judgeable