Problems

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Total results29,441 problems

Estonian Number Words Sort
Medium5
String, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
End-Balanced Subarrays
Medium5
Prefix sum, Hash map
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Illuminated Lights II
Medium5
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Two Squares
Medium5
Math, Combinatorics
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
String Split
Medium5
String, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Wizard Junkeun and the Magic Workshop
Medium5
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Nothing Everything
Medium5
Graph, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dutch Pay
Medium5
Sorting, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Hungry Muto
Medium5
Graph, Number theory
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Training, Round 3
Medium5
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Word Game
Medium5
Brute force, String+2
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Number Assignment
Medium5
Backtracking, Math+1
No attempts yet
Time limit
0.1s
Memory limit
2048 MB
Judgeable
Triangle
Medium5
Number theory, Geometry+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Intergalactic Team
Medium5
Graph, Union-find
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Perfect Squares
Medium5
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Pianissimo
Medium5
Sorting, Array
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Unskippable subway game
Medium5
Game theory, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Comso Christmas
Medium5
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sequence and Queries HY
Medium5
Array, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Addition palindrome sequences and trees
Medium5
Tree, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Nayeon Sort
Medium5
Array, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Checker-Circle Property
Medium5
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Maximum Submatrix Sum
Medium5
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
0.2s
Memory limit
1024 MB
Judgeable
Evolving Etymology
Medium5
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Programmers and Stones
Medium5
Game theory, Math
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Minimization by Swaps
Medium5
Greedy, Queue+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Magnet Play
Medium5
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Strange Operation
Medium5
Math, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
U, Our Star!
Medium5
Dynamic programming, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Counting portal
Medium5
Matrix, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Extreme Job: The Dietitian
Medium5
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Morning Routine and Roll Call
Medium5
Dynamic programming, Array
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Choosing Chopsticks
Medium5
Binary search, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Strange Grid
Medium5
Sorting, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fun Pipe Puzzle
Medium5
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Corridor
Medium5
Dynamic programming, Prefix sum
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Area
Medium5
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Taking Medicine
Medium5
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Break the Tree
Medium5
Tree, BFS
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ribbon on the Christmas Present
Medium5
Divide and conquer, Recursion+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
The Sparsest Number in Between
Medium5
Bit manipulation, Greedy+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Odd and Even Game
Medium5
Game theory, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fix Flooded Floor
Medium5
Dynamic programming, Implementation
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Mahjong Giant Robot 1
Medium5
Math, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Not East Two in This Match! 1
Medium5
Combinatorics, Backtracking+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Job Completion
Medium5
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Double Derangement
Medium5
Dynamic programming, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sum at Most K
Medium5
Sorting, Two pointers
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cooking Steaks
Medium5
Greedy, Implementation+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Powers of Two
Medium5
Bit manipulation, Math+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Plus or Times
Medium5
Dynamic programming, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Horse Carts
Medium5
Greedy, Heap+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Chocolate Bar
Medium5
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Double Chunks
Medium5
Dynamic programming, Hash map
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Counting DFS Trees
Medium5
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Feng Shui
Medium5
Array, Greedy
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
GCDDCG
Medium5
Math
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Star Wars
Medium5
Dynamic programming, Matrix
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Monster Warehouse
Medium5
Simulation, Tree+2
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Conference Rides
Medium5
Binary search, Graph
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Old Orhei
Medium5
Segment tree, Array
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
AI Armagedon
Medium5
Greedy, Array+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Inspiring Professors
Medium5
Greedy, Sorting
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Bitcoin Bubble
Medium5
Stack, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Coatis and Owls
Medium5
Simulation, Stack+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Efficient Grading
Medium5
Greedy, Math
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Fraud Checking
Medium5
Hash map, String+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Heraldic Prediction
Medium5
Math, Number theory
No attempts yet
Time limit
0.5s
Memory limit
2048 MB
Judgeable
Banitsa
Medium5
Graph, BFS+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Family Tree
Medium5
Tree, BFS
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Sangheon's Course Registration Challenge
Medium5
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Integration of Lines and Poker
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Lights-Out Time
Medium5
Bit manipulation, Hash map+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Centrifuge
Medium5
Tree, DFS+1
No attempts yet
Time limit
1.5s
Memory limit
2048 MB
Judgeable
Periodic Sequence
Medium5
String, String matching
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Scheduling
Medium5
Greedy, Heap+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
The Great Lever Challenge
Medium5
Simulation, BFS+1
No attempts yet
Time limit
20s
Memory limit
2048 MB
Judgeable
Remove Exactly Two
Medium5
Tree, Greedy+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Particle Accelerator
Medium5
Tree, DFS
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
The Interview Problem
Medium5
Greedy, String+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Average Value
Medium5
Array, Math
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Permutations and Cycles (Minimum Version)
Medium5
Array, Greedy+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Make a Palindrome
Medium5
Hash map, String+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Except One
Medium5
Combinatorics, Number theory+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Easily Broadcastable Tensors
Medium5
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Benzinska
Medium5
Greedy, Heap
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Proof of the Pythagorean Theorem
Medium5
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Art Class
Medium5
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Painting Exchange
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Fractal Plane
Medium6
Divide and conquer, Recursion+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Decreasing Number
Medium6
Combinatorics, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Nonconsecutive Sort
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Matrix Transformation
Medium6
Greedy, Matrix+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Park Seongwon's Probability
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Catching Mice
Medium6
Geometry, Binary search+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Checkers
Medium6
Math, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Card Shuffling
Medium6
Array, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Card Organization 1
Medium6
Greedy, Implementation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Power Plants
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Search Engine
Medium6
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Estonian Number Words SortSort N integers given as Estonian number words, where the words are first converted to values and then ordered in non-decreasing order.	Medium5	StringSorting+1	No attempts yet	1s	1024 MB	Judgeable
End-Balanced SubarraysCount the subarrays with l < r where the sum of the two endpoint elements equals the sum of the elements strictly between them.	Medium5	Prefix sumHash map	No attempts yet	1s	1024 MB	Judgeable
Illuminated Lights IICount the subsets of lights, each pointing L or R, that illuminate every light in the row, modulo 1e9+7.	Medium5	Dynamic programmingString	No attempts yet	1s	1024 MB	Judgeable
Two SquaresCount the ways to place a red and a blue k by k square on an n by m grid without overlap, modulo 10^9+7.	Medium5	MathCombinatorics	No attempts yet	2s	1024 MB	Judgeable
String SplitGiven strings s and t, decide whether repeatedly deleting all odd-indexed or all even-indexed characters of s can turn s into t.	Medium5	StringMath+1	No attempts yet	1s	1024 MB	Judgeable
Wizard Junkeun and the Magic WorkshopGiven N merge steps where each new stone is the sum of the two largest stones so far, print the last stone's value modulo 1e9+7.	Medium5	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Nothing EverythingDecide whether a graph can be built by adding each vertex either isolated or joined to all earlier vertices, and output the operations if it can.	Medium5	GraphGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Dutch PaySplit each dish's price evenly among the diners present at its order time, then output the average amount paid per person.	Medium5	SortingPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
The Hungry MutoGiven an evolution map on n ingredients, answer Q queries: count starting ingredients x where one evolution step gives the same result as c evolution steps.	Medium5	GraphNumber theory	No attempts yet	1.5s	512 MB	Judgeable
Training, Round 3Given n problems, k weeks, and p problems picked per week, find the probability that some two weekly sets share a problem, modulo 998244353.	Medium5	MathCombinatorics	No attempts yet	1s	2048 MB	Judgeable
Word GameGiven up to 5 lowercase words, merge them pairwise by overlapping suffix and prefix to get the shortest possible single word, breaking ties lexicographically, or output -1 if impossible.	Medium5	Brute forceString+2	No attempts yet	2s	2048 MB	Judgeable
Number AssignmentCount the ways to assign distinct numbers 1 to 13 to cells a through m so that each row and column total matches the given values A through H.	Medium5	BacktrackingMath+1	No attempts yet	0.1s	2048 MB	Judgeable
TrianglePick one interior lattice point on each side of a lattice triangle and find the largest and smallest doubled area of the triangle they form, or -1.	Medium5	Number theoryGeometry+1	No attempts yet	1s	2048 MB	Judgeable
Intergalactic TeamGiven directed wish lists, count the teams of exactly k competitors where every pair names each other and mutual pairs stay together.	Medium5	GraphUnion-find	No attempts yet	3s	2048 MB	Judgeable
Perfect SquaresGiven n up to 10^12, find three integers whose squares sum to n, or print -1 if no such triple exists by Legendre's three-square condition.	Medium5	MathNumber theory+1	No attempts yet	1s	2048 MB	Judgeable
PianissimoGiven each note's played power and the sheet's dynamic markings, count the unordered pairs of notes with different dynamics whose power order breaks the dynamic order.	Medium5	SortingArray	No attempts yet	1s	2048 MB	Judgeable
Unskippable subway gameGiven N stations where some are transfer stops, two players take turns advancing a subway model, and whoever places it at station N wins. Find the winner.	Medium5	Game theoryArray+1	No attempts yet	1s	1024 MB	Judgeable
Comso ChristmasDecide if N problems, each needing s_i wrong answers before its accepted verdict, can be submitted so that verdicts alternate, starting with Accepted.	Medium5	GreedySorting+1	No attempts yet	2s	1024 MB	Judgeable
Sequence and Queries HYGiven a sequence A of length N, answer each query m by printing the minimum and maximum of the remainders A_i mod m, with m up to 300000.	Medium5	ArrayMath+1	No attempts yet	2s	1024 MB	Judgeable
Addition palindrome sequences and treesCount the leaf-to-leaf paths in a full binary tree whose values can be merged by adding adjacent pairs into a palindrome of length 2 or more.	Medium5	TreeDFS+1	No attempts yet	1s	1024 MB	Judgeable
Nayeon SortGiven an array, find the minimum number of stacks needed to sort it in ascending order using Nayeon sort.	Medium5	ArrayBinary search+1	No attempts yet	2s	1024 MB	Judgeable
Checker-Circle PropertyGiven N points on a circle of radius R, decide whether they all lie on two opposite quarter arcs cut by perpendicular lines through the origin.	Medium5	GeometrySorting+1	No attempts yet	1s	1024 MB	Judgeable
Maximum Submatrix SumGiven an N by M integer matrix, find the maximum sum of any contiguous rectangular submatrix, where the empty submatrix counts as 0.	Medium5	Dynamic programmingPrefix sum+1	No attempts yet	0.2s	1024 MB	Judgeable
Evolving EtymologyGiven a word s of length n, apply the every-second-letter transform k times (k up to 10^18) and print the resulting word.	Medium5	MathNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Programmers and StonesTwo players alternately pick any nonempty set of nonempty piles and remove one stone from each; determine the winner under optimal play.	Medium5	Game theoryMath	No attempts yet	2s	2048 MB	Judgeable
Minimization by SwapsGiven a digit string s and at most k swaps of adjacent digits, find the smallest number that can be formed.	Medium5	GreedyQueue+1	No attempts yet	2s	2048 MB	Judgeable
Magnet PlayFind the maximum sum of card values a magnet can collect on a 2xN grid while moving from the top-left to the bottom-right cell, counting each card once.	Medium5	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Strange OperationEach operation sets one element to the negative of the current sum; find the maximum sum reachable by repeating it.	Medium5	MathArray	No attempts yet	1s	1024 MB	Judgeable
U, Our Star!Given products with limited counts and prices, find the smallest payment that maximizes points, where points are floor(payment / X) times Y, capped at D.	Medium5	Dynamic programmingMath	No attempts yet	1s	1024 MB	Judgeable
Counting portalCount the rectangles (r1, c1, r2, c2) that can become a Nether portal after placing obsidian, where border cells contain no 2 and interior cells are all 0.	Medium5	MatrixPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Extreme Job: The DietitianStudents with eating times b_i can be ordered in any line, and each sits at its position minute. Find the maximum number seated at the same minute.	Medium5	GreedySorting	No attempts yet	1s	1024 MB	Judgeable
Morning Routine and Roll CallChoose actions whose stage prerequisites are met and whose total time is at most T, then output the maximum total satisfaction.	Medium5	Dynamic programmingArray	No attempts yet	1.5s	1024 MB	Judgeable
Choosing ChopsticksGiven N colors with A_i chopsticks each, find the minimum number X of chopsticks that guarantees K same-color pairs for any selection, or print -1 if no X works.	Medium5	Binary searchGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Strange GridGiven N people on a grid where each direction has its own movement cost, find the minimum total cost for everyone to gather at one cell.	Medium5	SortingPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Fun Pipe PuzzleGiven a 2-row grid of I and L pipes, decide whether rotating them can connect a path from cell (1, 1) to cell (2, N).	Medium5	Dynamic programmingGreedy+1	No attempts yet	1s	2048 MB	Judgeable
CorridorGiven N corridor segments with one-use teleporters that send David back to earlier segments, find his total walking time to exit, modulo 10^9+7.	Medium5	Dynamic programmingPrefix sum	No attempts yet	1s	2048 MB	Judgeable
AreaGiven the areas of the long and short diagonal plots in an N by N grid, find the area of the plot at column X, row Y as a prime factorization.	Medium5	MathNumber theory	No attempts yet	1s	2048 MB	Judgeable
Taking MedicineDecide whether three doses a day, each taken right after a meal within a fixed window, can keep the effect of K minutes active without a gap for N days.	Medium5	GreedyMath+1	No attempts yet	1s	1024 MB	Judgeable
Break the TreeGiven a tree rooted at node 0, find the XOR of all f(x), where each f(x) records which nodes stay connected to 0 after node x's edges are removed.	Medium5	TreeBFS	No attempts yet	1s	1024 MB	Judgeable
Ribbon on the Christmas PresentGiven n ribbon sections with target shade levels, find the fewest dyeing steps, where each step dyes a contiguous range and can only overdye with a darker shade.	Medium5	Divide and conquerRecursion+1	No attempts yet	2s	2048 MB	Judgeable
The Sparsest Number in BetweenGiven positive integers a and b with a at most b, find the integer in that range with the fewest 1 bits in binary, choosing the smallest if there is a tie.	Medium5	Bit manipulationGreedy+1	No attempts yet	2s	2048 MB	Judgeable
Odd and Even GameTwo players alternately take cards, and after each player's first card, every card they take must share its parity. Determine the winner under optimal play.	Medium5	Game theoryDynamic programming	No attempts yet	1s	1024 MB	Judgeable
Fix Flooded FloorGiven a 2xn grid where '#' marks blocked cells and '.' marks empty cells, decide if the empty cells have exactly one, multiple, or no tilings with 1x2 dominoes.	Medium5	Dynamic programmingImplementation	No attempts yet	3s	2048 MB	Judgeable
Mahjong Giant Robot 1Fill an H by W grid with C ones and D nines so every row sum is strictly larger than the row above it, or report -1 if that is impossible.	Medium5	MathGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Not East Two in This Match! 1Count the ways to pick 14 of the N drawn tiles that split into 1 pair and 4 sets, or into 7 distinct pairs.	Medium5	CombinatoricsBacktracking+1	No attempts yet	1s	1024 MB	Judgeable
Job CompletionGiven jobs with start deadlines s_i and durations t_i, find the most jobs that can be finished when they run one at a time from time 0.	Medium5	GreedySorting+1	No attempts yet	2s	2048 MB	Judgeable
Double DerangementGiven two permutations a and b of length N (up to 16), count the permutations c where c_i differs from both a_i and b_i at every index.	Medium5	Dynamic programmingBit manipulation	No attempts yet	1s	1024 MB	Judgeable
Sum at Most KGiven N pairs (a, b), find the largest b_i + b_j at most K over index pairs whose a values differ, or print NO if none exists.	Medium5	SortingTwo pointers	No attempts yet	1s	1024 MB	Judgeable
Cooking SteaksGiven steaks at each doneness level and cook times between adjacent levels, find the minimum total time to match all orders by moving steaks upward, or report -1.	Medium5	GreedyImplementation+1	No attempts yet	1s	2048 MB	Judgeable
Powers of TwoStarting from N = 0, apply Q queries that add or subtract a power of two, and print YES after each query where N is 0.	Medium5	Bit manipulationMath+1	No attempts yet	1s	2048 MB	Judgeable
Plus or TimesGiven a starting value P and N rounds where each round offers either adding c or multiplying by c, find the maximum final value.	Medium5	Dynamic programmingImplementation	No attempts yet	1s	2048 MB	Judgeable
Horse CartsGiven N treasures with weights and values and M carts with weight limits, each cart carries one treasure, so find the maximum total value you can take.	Medium5	GreedyHeap+1	No attempts yet	1s	2048 MB	Judgeable
Chocolate BarGiven an N by M chocolate bar and a target area K, find the fewest splits needed so that some pieces total exactly K.	Medium5	MathBrute force	No attempts yet	1s	2048 MB	Judgeable
Double ChunksSplit an array of N chunk values into consecutive pieces so all two-chunk pieces share one sum, and find the maximum number of such pieces.	Medium5	Dynamic programmingHash map	No attempts yet	1s	2048 MB	Judgeable
Counting DFS TreesCount the distinct preorder depth sequences of trees with n nodes whose leaves all sit at depth K, then multiply f(A_i) for all queries modulo 998244353.	Medium5	Dynamic programmingPrefix sum+1	No attempts yet	1s	2048 MB	Judgeable
Feng ShuiGiven a permutation of 1 to N, find the minimum number of adjacent swaps to make it decrease and then increase.	Medium5	ArrayGreedy	No attempts yet	1s	2048 MB	Judgeable
GCDDCGFor each round i, count ways to pick two disjoint non-empty decks whose GCDs both equal i, then sum i times that count modulo 998244353.	Medium5	Math	No attempts yet	1s	2048 MB	Judgeable
Star WarsPick one white piece on a grid so that, moving up one row at a time without landing on other white pieces, it captures the most black pieces.	Medium5	Dynamic programmingMatrix	No attempts yet	1s	2048 MB	Judgeable
Monster WarehouseSimulate a warehouse of nested containers under BUY, SELL, UNPACK, and PACK requests, then answer COUNT, CONTAINS, and MIN queries about goods.	Medium5	SimulationTree+2	No attempts yet	1s	2048 MB	Judgeable
Conference RidesAssign each carless attendee to one driver so that the time until every attendee reaches home is minimized.	Medium5	Binary searchGraph	No attempts yet	1s	2048 MB	Judgeable
Old OrheiWalk a one-way graph by the edge indices in a range of an array, answering range queries for the final vertex and supporting point updates.	Medium5	Segment treeArray	No attempts yet	3s	2048 MB	Judgeable
AI ArmagedonGiven the order in which T-shirts arrive for K piles, find the fewest times the script must move off a pile that is about to receive a shirt.	Medium5	GreedyArray+1	No attempts yet	1s	2048 MB	Judgeable
Inspiring ProfessorsAssign each lecture a hall with capacity at least its attendance, giving the friendliest lecturers the nicest halls first, or report impossible.	Medium5	GreedySorting	No attempts yet	3s	2048 MB	Judgeable
Bitcoin BubbleGiven price segments of consecutive days, find the maximum of the longest window around a day x where no price drops below the price on x, times that price.	Medium5	StackPrefix sum+1	No attempts yet	2s	2048 MB	Judgeable
Coatis and OwlsCoati and owl squads meet in a line, and each fight costs the winner ceil(l^2/w) pikemen. Simulate the battles and report the winning army and its remaining size.	Medium5	SimulationStack+1	No attempts yet	2s	2048 MB	Judgeable
Efficient GradingGiven n exams and a time t per grading or training step, find the minimum total time to grade all exams and the fewest graders needed to meet it.	Medium5	GreedyMath	No attempts yet	1s	2048 MB	Judgeable
Fraud CheckingGiven two code listings of n lines each, decide whether one can be turned into the other by consistent whole-word renames, and if so, print the sorted list of renames.	Medium5	Hash mapString+1	No attempts yet	1s	2048 MB	Judgeable
Heraldic PredictionGiven n, output an even m with n < m < n+50 such that p^2 + m is composite for every prime p.	Medium5	MathNumber theory	No attempts yet	0.5s	2048 MB	Judgeable
BanitsaGiven pairs of pieces on a circle whose connecting chords never cross, find the fewest toppings so that every paired pieces get different toppings.	Medium5	GraphBFS+1	No attempts yet	3s	2048 MB	Judgeable
Family TreeGiven a family tree of n people, find the minimum width of a drawing where children sit one level below parents and pictures in a level may shift sideways.	Medium5	TreeBFS	No attempts yet	3s	2048 MB	Judgeable
Sangheon's Course Registration ChallengeGiven N courses with preference and credits, choose a subset of at least one course with total credits at most M that maximizes total preference, and print the chosen indices.	Medium5	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Integration of Lines and PokerSimulate swaps on a grid of colored pieces with special effects and gravity, then total the elimination, chain, combo, pattern, and endgame scores.	Medium5	SimulationImplementation+1	No attempts yet	1s	2048 MB	Judgeable
Lights-Out TimeCount the row-flip subsets that leave at most one lit bulb in each column of an N by M grid of bulbs.	Medium5	Bit manipulationHash map+1	No attempts yet	2s	1024 MB	Judgeable
CentrifugeGiven a tree with fluid in each node, find each node's expected final fluid when a random node is the center and fluid flows outward, mod 998244353.	Medium5	TreeDFS+1	No attempts yet	1.5s	2048 MB	Judgeable
Periodic SequenceGiven two repeating digit blocks, decide whether one can match the other after repetition and cyclic shifting.	Medium5	StringString matching	No attempts yet	1s	2048 MB	Judgeable
SchedulingGiven n meetings with time windows, find integer start times so each one-hour meeting has at least one hour free before and after, or report -1 if impossible.	Medium5	GreedyHeap+1	No attempts yet	3s	2048 MB	Judgeable
The Great Lever ChallengeGiven a maze and levers that move the robot along the x or y axis with a flipping direction, print the lever indices that take the robot from @ to $.	Medium5	SimulationBFS+1	No attempts yet	20s	2048 MB	Judgeable
Remove Exactly TwoGiven a tree, remove exactly two vertices (each with its incident edges) to find the maximum number of connected components that remain.	Medium5	TreeGreedy+1	No attempts yet	2s	2048 MB	Judgeable
Particle AcceleratorThe accelerator is a tree of N rooms, and the task makes Q calls to generate with distinct room values v, but the statement never says what generate must return.	Medium5	TreeDFS	No attempts yet	5s	2048 MB	Judgeable
The Interview ProblemGiven a string of brackets and digits, can each digit delete that many earlier characters so the remaining brackets form a balanced sequence?	Medium5	GreedyString+1	No attempts yet	1s	2048 MB	Judgeable
Average ValueGiven an array of n integers (each at least 1, with very large values allowed), output one index whose element equals the geometric mean of the other elements.	Medium5	ArrayMath	No attempts yet	2s	2048 MB	Judgeable
Permutations and Cycles (Minimum Version)Given n and x, build a permutation of 1 to n where each adjacent pair sums to at most x, using the fewest cycles.	Medium5	ArrayGreedy+1	No attempts yet	2s	2048 MB	Judgeable
Make a PalindromeGiven a lowercase string, decide whether swapping characters two positions apart can turn it into a palindrome.	Medium5	Hash mapString+1	No attempts yet	2s	2048 MB	Judgeable
Except OneGiven a prime p and integers k and t, find the sum of products of all t-element subsets of {1, ..., p-1} without k, modulo p.	Medium5	CombinatoricsNumber theory+1	No attempts yet	1s	2048 MB	Judgeable
Easily Broadcastable TensorsFind the fewest 1s to insert into two size lists so that, aligned from the right, every overlapping pair is equal or contains a 1.	Medium5	Dynamic programmingArray	No attempts yet	1s	2048 MB	Judgeable
BenzinskaFind the fewest restaurants Malnar must dine at to cycle from x=0 to x=X with starting energy D without energy going negative, or -1 if impossible.	Medium5	GreedyHeap	No attempts yet	1s	2048 MB	Judgeable
Proof of the Pythagorean TheoremCount the ordered pairs (a, b) of positive integers up to N for which the yellow square's area is an integer multiple of one blue triangle's area.	Medium5	MathNumber theory	No attempts yet	1s	1024 MB	Judgeable
Art ClassGiven N points above the x-axis, count the distinct intersection points of the slope +1 and slope -1 lines drawn through them, on or above the axis.	Medium5	GeometrySorting+1	No attempts yet	1s	1024 MB	Judgeable
Painting ExchangeGiven who can sell to whom at what price, find the longest chain of distinct buyers starting from artist 1 where each resale price never drops below the purchase price.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	2s	128 MB	Judgeable
Fractal PlanePrint a rectangular window of the grid at time s, where each step splits every cell into N x N and blacks out a centered K x K block.	Medium6	Divide and conquerRecursion+2	No attempts yet	2s	128 MB	Judgeable
Decreasing NumberGiven N, find the N-th smallest non-negative integer whose digits strictly decrease from left to right, or output -1 if none exists.	Medium6	CombinatoricsGreedy+2	No attempts yet	1s	512 MB	Judgeable
Nonconsecutive SortRearrange up to 50 integers into the lexicographically smallest sequence where no value is immediately followed by the value one greater than it.	Medium6	GreedySorting+2	No attempts yet	2s	128 MB	Judgeable
Matrix TransformationGiven two binary matrices, find the minimum number of 3x3 submatrix bit-flips needed to turn matrix A into matrix B, or report impossibility.	Medium6	GreedyMatrix+1	No attempts yet	2s	128 MB	Judgeable
Park Seongwon's ProbabilityCount permutations of up to 15 numbers whose concatenation is divisible by K, and output the probability as a reduced fraction.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	2s	128 MB	Judgeable
Catching MiceGiven moving mice with initial positions and velocities, find the largest square cage side length for which no drop time can enclose all mice simultaneously.	Medium6	GeometryBinary search+1	No attempts yet	2s	128 MB	Judgeable
CheckersFor each k, find the fewest single-cell moves to bring at least k checkers onto one cell. Manhattan distances decide the cost.	Medium6	MathSorting+1	No attempts yet	2s	128 MB	Judgeable
Card ShufflingGiven a permutation of card positions and a target assignment of each card to a player, find the minimum number of shuffles so every card reaches its target player, or -1.	Medium6	ArrayMath+2	No attempts yet	2s	128 MB	Judgeable
Card Organization 1Each box lists counts per card color; find the minimum number of box-to-box transfers so at most one mixed box remains and every other color sits in a single box.	Medium6	GreedyImplementation+2	No attempts yet	2s	128 MB	Judgeable
Power PlantsGiven restart costs between plants and which plants are already on, find the minimum total cost to reach at least P working plants, or -1.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	2s	128 MB	Judgeable
Search EngineGiven directed links between websites, compute one website's trust score by summing scores of linking sites only when no cycle would result.	Medium6	GraphDFS+2	No attempts yet	2s	128 MB	Judgeable