Problems

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Total results29,455 problems

Rock, Scissors, Paper
Medium5
Simulation, Matrix+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
String Exponentiation
Medium5
String, String matching+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Coprime
Medium5
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Multiplication Game
Medium5
Game theory, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Multiple Made Only of Ones
Medium5
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tight Words
Medium5
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Splitting Teams Fairly
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Building the Constellation
Medium5
Minimum spanning tree, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Snap
Medium5
Simulation, Queue+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Steps
Medium5
Math, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Old Wine Into New Bottles
Medium5
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ferry Loading
Medium5
Dynamic programming, Greedy
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Factovisors
Medium5
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Prime Distance
Medium5
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Chocolate Chip Cookies
Medium5
Geometry, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hippity Hopscotch
Medium5
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Painted Cube
Medium5
BFS, Graph+2
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Lightning Lessons
Medium5
Simulation, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Palindromic Primes Category in Jeopardy!
Medium5
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Games R Us
Medium5
Hash map, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Thinking Inside the Box
Medium5
Geometry, Intervals+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Frenemies
Medium5
DFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Know When to Hold Them
Medium5
Sorting, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Extent of the Problem
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
1 Is an Interesting Number
Medium5
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Sidewinder Sleeps Tonite
Medium5
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Blue Jeans
Medium5
String, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Plinko
Medium5
Dynamic programming, Probability+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
MisLED
Medium5
Brute force, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Crash and Go(relians)
Medium5
Simulation, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Egyptian Fractions
Medium5
Greedy, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
RIPOFF
Medium5
Dynamic programming, Sliding window
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Typesetting
Medium5
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rock Skipping
Medium5
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Overflowing Bookshelf
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Permutation Code
Medium5
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Safecracker
Medium5
Brute force, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Index Generation
Medium5
String, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sum It Up
Medium5
Backtracking, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Board Silly
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Another Puzzling Problem
Medium5
Implementation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mark-up Processor
Medium5
String, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dueling Philosophers
Medium5
Graph, Topological sort+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Balloons
Medium5
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Abstract Extract
Medium5
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Signal Strength
Medium5
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mobiles Alabama
Medium5
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Turn of the Shrew
Medium5
Bit manipulation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Auctions R Us
Medium5
Simulation, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tangled in Cables
Medium5
Minimum spanning tree, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Reverse Roman Notation
Medium5
Implementation, Stack+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The End of the World
Medium5
Recursion, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Juggler
Medium5
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Camping
Medium5
Math, Greedy
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fuel Stops
Medium5
Greedy, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Trees
Medium5
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Emergency Room
Medium5
Simulation, Heap+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Stock Prices
Medium5
Sorting, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Railroad
Medium5
Dynamic programming, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Range
Medium5
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shuffling
Medium5
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Trucking
Medium5
Graph, Shortest path+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Open and Close
Medium5
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Squares
Medium5
Geometry, Hash map+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
PERMS
Medium5
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sum of Squared Digits
Medium5
Hash map, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Normal Form
Medium5
Tree, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dividing the Land
Medium5
Sorting, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Einbahnstrasse
Medium5
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rotating Rings
Medium5
Array, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Walk Like an Egyptian
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sequence Walking
Medium5
Dynamic programming, Two pointers
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gift from the Goddess of Programming
Medium5
Simulation, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Introduction to Digital Circuits
Medium5
Recursion, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Analyzing Login/Logout Records
Medium5
Intervals, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cut the Cake
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Organize Your Train part II
Medium5
String, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Polygonal Line Shape Search
Medium5
Geometry, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Horror List
Medium5
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Robots on a Grid
Medium5
Dynamic programming, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
ls
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Royal Succession
Medium5
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dirty Driving
Medium5
Sorting, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Great Geek Game-show 3000!
Medium5
Combinatorics, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Playfair Cipher
Medium5
Simulation, Matrix+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shopaholic
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Constellations
Medium5
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Image Segmentation
Medium5
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bat Positioning
Medium5
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Manito Chains
Medium5
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Going to the Movies
Medium5
Bit manipulation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Road Trip
Medium5
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rig Placement
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Seymour the Seal
Medium5
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Foreclosure Borough
Medium5
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Stimulus Package
Medium5
Brute force, Implementation+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Clue
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Perfect Alibi
Medium5
Implementation, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Problem-Free Problem Set
Medium5
Bit manipulation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Overlap!
Medium5
Implementation, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Rock, Scissors, PaperGiven a grid of Rock, Scissors, and Paper cells, simulate simultaneous battles each day and print the grid after n days.	Medium5	SimulationMatrix+1	No attempts yet	1s	128 MB	Judgeable
String ExponentiationGiven a string, find the largest exponent n such that the string is a repetition of some base string a raised to n.	Medium5	StringString matching+1	No attempts yet	1s	256 MB	Judgeable
CoprimeFor each n up to 1e9, count how many positive integers less than n share no common factor with n, handling several test cases until a 0.	Medium5	Number theoryMath+1	No attempts yet	1s	128 MB	Judgeable
Multiplication GameAlice and Bob multiply a running product by 2 to 9 in turn; find who forces the product to reach n first with optimal play.	Medium5	Game theoryDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
A Multiple Made Only of OnesGiven n not divisible by 2 or 5, find the number of digits of the smallest repunit (all ones) that n divides.	Medium5	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Tight WordsCount words of length n over digits 0..k where adjacent digits differ by at most 1, then print that count as a percentage rounded to five decimals.	Medium5	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Splitting Teams FairlySplit N people into two teams differing in size by at most one so their total weight difference is minimized, then print both totals in increasing order.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
Building the ConstellationGiven n points in the plane, connect all of them with straight segments of Euclidean length so the total cost is minimized.	Medium5	Minimum spanning treeGraph+2	No attempts yet	1s	128 MB	Judgeable
SnapSimulate the two-player Snap card game with card flipping, pile recycling, and a fixed random tie-breaker for up to 1000 turns.	Medium5	SimulationQueue+1	No attempts yet	1s	128 MB	Judgeable
StepsFind the minimum number of steps from x to y when consecutive step lengths differ by at most 1 and the first and last lengths are 1.	Medium5	MathGreedy+1	No attempts yet	1s	128 MB	Judgeable
Old Wine Into New BottlesGiven a wine volume and bottle sizes with min and max capacities, maximize the bottled amount and print the leftover in millilitres.	Medium5	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
Ferry LoadingLoad the longest prefix of cars onto two lanes of bounded total length, choosing lanes to maximize cars loaded and break ties lexicographically.	Medium5	Dynamic programmingGreedy	No attempts yet	1s	128 MB	Judgeable
FactovisorsFor each pair n and m, decide whether m divides n! by comparing the prime factors of m against those of n!.	Medium5	Number theoryMath	No attempts yet	1s	128 MB	Judgeable
Prime DistanceFor each query range [L, U], find the closest and farthest pairs of consecutive primes inside it.	Medium5	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Chocolate Chip CookiesGiven up to 200 points, find the maximum number that fit inside any circle of radius 2.5 cm, allowing the circle to extend past the dough edge.	Medium5	GeometryBrute force+1	No attempts yet	1s	128 MB	Judgeable
Hippity HopscotchOn an n by n grid of penny stacks, starting at (0,0) and jumping up to k cells in a row or column to a strictly larger stack, find the maximum total collected.	Medium5	Dynamic programmingSorting+1	No attempts yet	1s	128 MB	Judgeable
Painted CubeA cube rolls on a grid swapping paint with squares; find the minimum rolls to reach the goal with all six faces painted.	Medium5	BFSGraph+2	No attempts yet	10s	512 MB	Judgeable
Lightning LessonsSimulate repeatedly replacing each sequence by consecutive differences until it turns all zero, fizzles, or becomes a negative single value.	Medium5	SimulationMath+1	No attempts yet	1s	128 MB	Judgeable
Palindromic Primes Category in Jeopardy!Count n-digit numbers that are palindromic primes in a given base and below 2^31, reading digit/base pairs until 0 0.	Medium5	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Games R UsGroup users into equivalence classes by identical directory access sets, then report classes of size 2 or more.	Medium5	Hash mapSorting+2	No attempts yet	1s	128 MB	Judgeable
Thinking Inside the BoxFor each test case, report every stored Data Box that intersects, touches, or overlaps at least one Query Box, accounting for longitude wraparound.	Medium5	GeometryIntervals+1	No attempts yet	1s	128 MB	Judgeable
FrenemiesFor each dataset, sum the signed scores of all simple paths without neutral links between a given person and every other person.	Medium5	DFSGraph+2	No attempts yet	1s	128 MB	Judgeable
Know When to Hold ThemRank a set of five-card poker hands from most to least valuable, using nine standard hand categories and their tie-breakers.	Medium5	SortingImplementation+2	No attempts yet	1s	128 MB	Judgeable
The Extent of the ProblemSimulate RADDD's two-step defragmentation passes over disk blocks and output the final extent layout of every file.	Medium5	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
1 Is an Interesting NumberFor each set of up to 100 integers, count how many of 13 listed properties each number satisfies and print all numbers with the maximum count.	Medium5	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
The Sidewinder Sleeps ToniteGiven a drawn grid of segments and cell numbers, decide whether the drawing is a single closed loop matching every numbered cell.	Medium5	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Blue JeansGiven up to 10 DNA strings of length 60, find the longest substring that appears in all of them, breaking ties alphabetically, or report none of length 3 or more.	Medium5	StringBrute force+2	No attempts yet	1s	128 MB	Judgeable
PlinkoGiven rigged Plinko boards with per-peg right-move probabilities, compute for each start and end column the number of distinct paths and the truncated percentage chance.	Medium5	Dynamic programmingProbability+2	No attempts yet	1s	128 MB	Judgeable
MisLEDGiven two observed 7-segment displays with the same unknown burnt-out segments, find the second observed time in 12-hour format.	Medium5	Brute forceBit manipulation+1	No attempts yet	1s	128 MB	Judgeable
Crash and Go(relians)After each Gorelian lands in order, groups merge when one radio reaches another, meeting at the unweighted average of group positions and combining ranges by root sum of squares; report the final group count.	Medium5	SimulationUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Egyptian FractionsApply the greedy Egyptian fraction algorithm to M/N, capping each remainder's denominator below 1,000,000, and print the unit fraction denominators.	Medium5	GreedyNumber theory+2	No attempts yet	1s	128 MB	Judgeable
RIPOFFA token moves 1 to S squares per turn and must exit a board of N labeled squares within T turns; maximize the total of the squares landed on.	Medium5	Dynamic programmingSliding window	No attempts yet	1s	128 MB	Judgeable
TypesettingPack bitmap glyphs as tightly as possible so no visible pixels from different glyphs touch horizontally, then print the result.	Medium5	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
Rock SkippingFor each lake map, find the throw (start, skip distance) that maximizes count, then length, then start, then smallest distance, and print it.	Medium5	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
Overflowing BookshelfSimulate a fixed-width shelf through add (push books leftward) and remove events; at End list the surviving books left to right.	Medium5	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Permutation CodeGiven a cipher key (S, P, x) and ciphertext C, invert the described encryption to recover the plaintext M.	Medium5	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
SafecrackerGiven a target T and up to 12 distinct uppercase letters, find five distinct letters whose signed power sum equals T; if several work, print the lexicographically greatest string.	Medium5	Brute forceBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Index GenerationParse markers in a multi-page document, collect page references for primary and secondary index entries, and print the index sorted case-insensitively.	Medium5	StringSimulation+2	No attempts yet	1s	128 MB	Judgeable
Sum It UpGiven a target and up to 12 numbers, list every distinct subset sum equal to the target, sorted in decreasing lexicographic order.	Medium5	BacktrackingSorting+2	No attempts yet	1s	128 MB	Judgeable
Board SillyGiven an 8x8 board of X and O pieces, list all legal moves for one player, where each piece moves exactly as many squares as pieces line its direction.	Medium5	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Another Puzzling ProblemEach jigsaw piece carries four integer edge labels; match opposite labels to place every piece in the N by N grid, then print the assembled picture.	Medium5	ImplementationBrute force+2	No attempts yet	1s	128 MB	Judgeable
Mark-up ProcessorStrip a small mark-up language from text: handle bold, italic, size, and a toggle that turns processing off, printing only the plain characters.	Medium5	StringSimulation+2	No attempts yet	1s	128 MB	Judgeable
Dueling PhilosophersGiven m precedence edges among n essays, decide whether the es-says have zero, exactly one, or more than one valid topological ordering.	Medium5	GraphTopological sort+2	No attempts yet	2s	128 MB	Judgeable
BalloonsAssign each team's balloons from rooms A and B, respecting supply limits, to minimize total travel distance.	Medium5	GreedySorting	No attempts yet	1s	128 MB	Judgeable
Abstract ExtractFor each article, pick the topic sentence of every paragraph with three or more sentences and print them in order.	Medium5	StringSimulation+1	No attempts yet	1s	128 MB	Judgeable
Signal StrengthFind the maximum signal strength reaching switch N-1 from switch 0 through a switch network with gain or loss multipliers on nodes and edges.	Medium5	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Mobiles AlabamaParse a nested mobile description and compute, for each bar, the tie point that balances the weights hanging from its two sides.	Medium5	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
The Turn of the ShrewEach child's code must differ from the bitwise OR of some male and female adult code; find the minimum Hamming distance over all pairs.	Medium5	Bit manipulationBrute force+2	No attempts yet	1s	128 MB	Judgeable
Auctions R UsSimulate one day of auctions: process auctions by end time, deduct each winning bid from the bidder's balance, and report winners or unmet reserves.	Medium5	SimulationSorting+1	No attempts yet	1s	128 MB	Judgeable
Tangled in CablesCompute the minimum spanning tree of a town map and compare its total length against the available spool of cable.	Medium5	Minimum spanning treeGraph+2	No attempts yet	1s	128 MB	Judgeable
Reverse Roman NotationSimulate a stack calculator where operands are Roman numerals; parse and print them, and handle underflow, division by zero, and out-of-range errors.	Medium5	ImplementationStack+2	No attempts yet	1s	128 MB	Judgeable
The End of the WorldGiven a valid intermediate state of the Towers of Hanoi, compute how many more moves remain in the optimal solution.	Medium5	RecursionDivide and conquer+2	No attempts yet	1s	128 MB	Judgeable
JugglerBalls sit in a circle with one in hand; rotate either way or drop the held ball, which brings its clockwise neighbor into hand. Find the fewest moves to drop all balls in a given order.	Medium5	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
CampingGiven limits L, P, V, find the most days out of V that satisfy using at most L days in any window of P consecutive days.	Medium5	MathGreedy	No attempts yet	1s	128 MB	Judgeable
Fuel StopsFind all valid starting cities in a circular tour where fuel supply matches demand, and the tank never goes negative.	Medium5	GreedyPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
TreesGiven an undirected graph, count its connected components that contain no cycle and report the count per test case.	Medium5	GraphUnion-find+2	No attempts yet	1s	256 MB	Judgeable
Emergency RoomSimulate an emergency room where doctors pick the waiting patient with the highest-priority next treatment, and report each patient's release time.	Medium5	SimulationHeap+2	No attempts yet	1s	128 MB	Judgeable
Stock PricesFor each test case, report the days with the k1 lowest prices (days ascending) and the k2 highest prices (days descending), breaking ties by a stated rule.	Medium5	SortingGreedy+1	No attempts yet	2s	128 MB	Judgeable
RailroadGiven two sequences, decide whether a target sequence can be formed by repeatedly taking the front car of either train; once one train empties, the rest follow in order.	Medium5	Dynamic programmingTwo pointers+2	No attempts yet	1s	128 MB	Judgeable
RangeGiven fuel and odometer readings over time, compute average consumption from intervals where fuel decreased, then estimate remaining driving range.	Medium5	ImplementationMath+1	No attempts yet	1s	128 MB	Judgeable
ShufflingGiven a fixed permutation of N cards and a target order, find the minimum number of times to apply the permutation to reach the target, or -1 if impossible.	Medium5	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
TruckingFor each graph case, find the largest cargo height allowing a route, then the shortest route length among routes that allow it.	Medium5	GraphShortest path+2	No attempts yet	3s	128 MB	Judgeable
Open and CloseCompute the morphological opening and closing of a binary image by a small structuring element for each test case.	Medium5	ImplementationSimulation+1	No attempts yet	1s	128 MB	Judgeable
SquaresCount the number of squares whose four corners all come from a given set of integer-coordinate points, allowing tilted squares.	Medium5	GeometryHash map+1	No attempts yet	1s	128 MB	Judgeable
PERMSFor each query (n, k), count permutations of 1..n having exactly k inversions, with n up to 18 and k up to 200.	Medium5	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Sum of Squared DigitsFor two starting numbers, follow the sum-of-squared-digits map and report the smallest total length until a value appears in both sequences, or 0 if they never meet.	Medium5	Hash mapSimulation+2	No attempts yet	1s	128 MB	Judgeable
Normal FormEvaluate a fully parenthesized AND/OR tree where odd levels are AND and even levels are OR, for several long test cases.	Medium5	TreeImplementation+2	No attempts yet	1s	128 MB	Judgeable
Dividing the LandFor each test case, split N cities with K-1 evenly spaced vertical or horizontal cuts, avoid cuts through cities, and print the minimum average \|count - N/K\| as a reduced fraction.	Medium5	SortingMath+2	No attempts yet	1s	128 MB	Judgeable
EinbahnstrasseFor each case, sum the shortest round-trip garage-to-car distances over all cars in a directed weighted city graph.	Medium5	Shortest pathGraph+1	No attempts yet	1s	128 MB	Judgeable
Rotating RingsGiven square grids, decide whether each can be turned into row-major sorted order using only independent rotations of each concentric ring.	Medium5	ArraySimulation+2	No attempts yet	1s	128 MB	Judgeable
Walk Like an EgyptianStones fill an N by N grid along a spiraling quarter-circle path; find the number placed in the top-right cell. Multiple N values per input.	Medium5	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Sequence WalkingGiven two ascending integer sequences, find the maximum sum of a forward walk that may switch sequences at shared values.	Medium5	Dynamic programmingTwo pointers	No attempts yet	1s	128 MB	Judgeable
Gift from the Goddess of ProgrammingEach log line records the entrance or exit of a visitor or the goddess (ID 000). Find the visitor who spends the most time at the altar while the goddess is present.	Medium5	SimulationSorting+2	No attempts yet	1s	128 MB	Judgeable
Introduction to Digital CircuitsParse three-valued logic expressions over P, Q, R and count how many of the 27 assignments make the expression evaluate to 2.	Medium5	RecursionImplementation+2	No attempts yet	1s	128 MB	Judgeable
Analyzing Login/Logout RecordsGiven login and logout records on PCs, compute for each query how many minutes a student used at least one PC during a time interval.	Medium5	IntervalsSimulation+2	No attempts yet	1s	128 MB	Judgeable
Cut the CakeSimulate n vertical cuts on a rectangular cake, tracking each rectangular piece and reassigning ids by area, then print all final piece areas sorted.	Medium5	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Organize Your Train part IICount distinct strings obtainable by splitting an input string at any point, optionally reversing each part, and concatenating the two parts in either order.	Medium5	StringBrute force+2	No attempts yet	1s	128 MB	Judgeable
Polygonal Line Shape SearchGiven a template orthogonal polygonal line, report which of up to 50 other lines match its shape under rotation and translation.	Medium5	GeometryImplementation+1	No attempts yet	1s	128 MB	Judgeable
Horror ListEach movie gets a level: 0 if on the horror list, else one plus the best level among similar movies; output the movie with the highest finite level, breaking ties by smallest ID.	Medium5	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Robots on a GridCount monotone right/down paths from the top-left to the bottom-right of an n by n grid with blocked cells, modulo 2^31-1, and report whether the goal is reachable at all, or reachable only with up and left moves allowed.	Medium5	Dynamic programmingDFS+2	No attempts yet	1s	128 MB	Judgeable
lsGiven a wildcard pattern where * matches any run of characters, print the input file names that match it, keeping input order.	Medium5	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable
Royal SuccessionGiven parent pairs for N people, compute each claimant's inherited fraction of the founder's blood and print the claimant with the largest fraction.	Medium5	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Dirty DrivingGiven distances to n cars ahead and a constant p, find the minimum gap to the nearest car so every car x ahead is at least p*(k+1) away, where k counts cars between.	Medium5	SortingGreedy+1	No attempts yet	1s	128 MB	Judgeable
Great Geek Game-show 3000!Given a random permutation of N names, each contestant follows its cycle up to K steps; find the probability every cycle has length at most K.	Medium5	CombinatoricsMath+2	No attempts yet	1s	128 MB	Judgeable
Playfair CipherBuild a 5x5 Playfair key table from a key phrase, split the plaintext into digraphs with X padding, and apply the row, column, or rectangle substitution rules. Output the uppercase ciphertext.	Medium5	SimulationMatrix+2	No attempts yet	1s	128 MB	Judgeable
ShopaholicGiven item prices, group them into triples so that the cheapest item in each triple is free, and maximize the total discount.	Medium5	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
ConstellationsGiven up to 500 star coordinates, connect each star to its nearest neighbor(s) and count the connected components of the resulting graph.	Medium5	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Image SegmentationGiven an H by W color image, band each RGB value by dividing by S, then count 8-connected regions of equal band triples whose pixel size is at least L.	Medium5	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Bat PositioningFind the point that equals the centroid of exactly the pointers lying at least 100 units away from it, rounding coordinates to the nearest integer.	Medium5	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
Manito ChainsGiven a permutation of N people, count the number of cycles in its functional graph. The input ends when N is 0.	Medium5	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Going to the MoviesGiven M movies each covering a subset of P preferences, find the smallest number of movies whose coverage includes all P preferences.	Medium5	Bit manipulationBrute force+2	No attempts yet	2s	128 MB	Judgeable
Road TripGiven a weighted tree rooted at city 1, remove exactly one non-root vertex so the round trip from city 1 covering all remaining cities is shortest, and report that length.	Medium5	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
Rig PlacementGiven n oil fields, a per-field investment cap m, and a total budget B, pick an investment amount for each field so total oil is maximized.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
Seymour the SealCount herring squares reachable from S when at most 3 goo squares may be crossed between visits to a cleaner.	Medium5	GraphBFS+1	No attempts yet	1s	128 MB	Judgeable
Foreclosure BoroughFor each polygon borough, compute the percentage of houses inside it that are in foreclosure, sort boroughs by rate, and print two-decimal rates with tie-breaking by borough number.	Medium5	GeometrySorting+1	No attempts yet	1s	128 MB	Judgeable
Stimulus PackageChoose a subset of at most 20 projects within budget B whose combined jobs meet every yearly target, maximizing total infrastructure gain.	Medium5	Brute forceImplementation+2	No attempts yet	5s	128 MB	Judgeable
ClueGiven the cards you were dealt and the responses to your own Clue queries, determine which locations, weapons, and suspects could still be the hidden cards.	Medium5	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
The Perfect AlibiEach witness gives a suspect, a place, and a time interval; conflicting pairs are discarded, and we list suspects with no surviving witness covering the crime time.	Medium5	ImplementationSorting+2	No attempts yet	1s	128 MB	Judgeable
Problem-Free Problem SetGiven N problems, each covering some of M required algorithms, find the smallest subset of problems covering all M algorithms, breaking ties by lexicographic order of problem names.	Medium5	Bit manipulationBrute force+2	No attempts yet	1s	128 MB	Judgeable
Overlap!Given each course's exam day and time slot and each student's course list, count students who have two or more finals that overlap in time.	Medium5	ImplementationSorting+2	No attempts yet	1s	128 MB	Judgeable