Problems

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Total results29,413 problems

Palindromic Crossword
Medium6
Union-find, Simulation+2
No attempts yet
Time limit
60s
Memory limit
1024 MB
Judgeable
Increasing Sequence Card Game
Medium6
Probability, Math+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Prime Card Game
Medium6
Brute force, Backtracking+2
No attempts yet
Time limit
4.5s
Memory limit
512 MB
Judgeable
Parking Lot
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
15s
Memory limit
512 MB
Judgeable
Surprise~
Medium6
Prefix sum, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
I Want to Get Home Fast!
Medium6
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
CAN WIN
Medium6
Prefix sum, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Box Drawing Character
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
String Telephone
Medium6
Brute force, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Reverse the Big Number
Medium6
String, Math+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Baeknam's Travel Preparation
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Baeknam's Preparation for Travel Preparation
Medium6
Math, Number theory+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Aa
Medium6
Greedy, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Making Triangles 2
Medium6
Math, Combinatorics+2
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Aging
Medium6
Simulation, Heap+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Rescue Mission
Medium6
Array, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Offices
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bunch of Paper
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bruteforce
Medium6
Sorting, Brute force+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Making a Square
Medium6
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Typing Contest
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tracking Bio-bots
Medium6
Intervals, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Prime Spiral
Medium6
BFS, Number theory+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Towers of Powers 2: Power Harder
Medium6
Sorting, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Reversing Roads
Medium6
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
A Careful Approach
Medium6
Binary search, Greedy+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
How Many Subtrees?
Medium6
Tree, Brute force+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Ten
Medium6
Prefix sum, Two pointers+2
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Treasure Hunter
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Triangles
Medium6
Geometry, Combinatorics+2
No attempts yet
Time limit
1.2s
Memory limit
1024 MB
Judgeable
Hanoi Tower K
Medium6
Recursion, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
I'm a Final Exam Kind of Person
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Adult Game
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bitcoin Is God and I Am Invincible
Medium6
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Celebrity
Medium6
Graph, Hash map+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Staying Hydrated
Medium6
Math, Greedy+2
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Fortune From Folly
Medium6
Probability, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hurdle Jumping
Medium6
Graph, Sorting+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Web Browser 1
Medium6
Simulation, Stack+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Course Swap
Medium6
Graph, Greedy+2
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Team Battle
Medium6
Math, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
League of Legends
Medium6
Prefix sum, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Making a Chip 2
Medium6
Dynamic programming, Intervals+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Sorting Problem
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Mountaineers
Medium6
Dynamic programming, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Watering
Medium6
Greedy, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Escape Room
Medium6
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Buffered Buffet
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Candy Contribution
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
git mv
Medium6
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Kudzu Kniving
Medium6
Math, Tree+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Monarchy in Vertigo
Medium6
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Kamenčići
Medium6
Game theory, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Boxes on a Shelf
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Two Slicers
Medium6
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Accelerometer calibration
Medium6
Math, Geometry+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Painting roofs
Medium6
Graph, Matrix+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Mr. Panda and Typewriter
Medium6
Dynamic programming, String
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Spiral Matrix
Medium6
Combinatorics, Simulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
City
Medium6
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Construct Points
Medium6
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Aunts
Medium6
Math, Sorting+1
No attempts yet
Time limit
7s
Memory limit
128 MB
Judgeable
Divisible Inversions
Medium6
Array, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Negative Base
Medium6
Math, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Same Songs
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Template for Search
Medium6
String, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Easy Equation
Medium6
Math, Brute force+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Heracles
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Medicine
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Young Energy Is Not Enough
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Making a Digram
Medium6
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
1, 2, 3, 4
Medium6
Math, Greedy
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Double Rainbow
Medium6
Two pointers, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Trio
Medium6
Hash map, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Cabbage
Medium6
Binary search, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Chinese Remainder Theorem
Medium6
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Baking Pans
Medium6
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Identical Scarves
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Cookie Run: Kingdom
Medium6
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Fire Behind Leaf Village
Medium6
BFS, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Fizz and Buzz
Medium6
Probability, Math+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Red-Black Tree
Medium6
Dynamic programming, Tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Interstellar Fantasy
Medium6
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Moves You Need to Make
Medium6
Array, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Magneti
Medium6
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Chiaki Chain
Medium6
Graph, Topological sort+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Juke Artem
Medium6
Tree, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Guessing Answers
Medium6
Greedy, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Miswritten DFS
Medium6
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Reorganizing Bus Routes
Medium6
Sorting, Intervals+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Escape Room
Medium6
Minimum spanning tree, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
What Was My Rank??
Medium6
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
String Decompression
Medium6
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Children and Gift Boxes
Medium6
Greedy, Heap+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Picky Children and Gift Boxes
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Forming Badminton Doubles Teams
Medium6
Sorting, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Glossary Arrangement
Medium6
Dynamic programming, Binary search+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Cyanide Rivers
Medium6
Greedy, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Two-Step Shortest Path 1
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
0.3s
Memory limit
512 MB
Judgeable
Two-Step Shortest Path 2
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Palindromic CrosswordFill as many dots as possible in a crossword grid so that every maximal horizontal and vertical word is a palindrome, and report the count and final grid.	Medium6	Union-findSimulation+2	No attempts yet	60s	1024 MB	Judgeable
Increasing Sequence Card GameFor each N, compute the expected number of cards kept when a shuffled 1..N pile is scanned and a card is taken only if it exceeds the last taken card.	Medium6	ProbabilityMath+2	No attempts yet	20s	1024 MB	Judgeable
Prime Card GamePartition n cards into m nonempty groups minimizing the maximum over groups of the distance from the group sum to the nearest prime different from it.	Medium6	Brute forceBacktracking+2	No attempts yet	4.5s	512 MB	Judgeable
Parking LotAssign N drivers to distinct parking spaces among 1..M so that the total distance from each driver's preferred space is minimized.	Medium6	Dynamic programmingSorting+2	No attempts yet	15s	512 MB	Judgeable
Surprise~Split every contiguous subarray into two adjacent nonempty parts, minimize the absolute sum difference, and among ties maximize the total sum.	Medium6	Prefix sumBrute force+2	No attempts yet	1s	512 MB	Judgeable
I Want to Get Home Fast!Given directed subway lines with travel times and departure intervals, find the earliest arrival time at station N when departing station 1 at time 0.	Medium6	Shortest pathGraph+2	No attempts yet	1s	512 MB	Judgeable
CAN WINCount the subarrays of an array of page word counts whose average is at least P.	Medium6	Prefix sumBinary search+2	No attempts yet	2s	512 MB	Judgeable
Box Drawing CharacterGiven a 3N by 3M grid where cells at odd parity positions became dots, fill them back so every drawn line segment connects on both ends.	Medium6	ImplementationSimulation+2	No attempts yet	1s	1024 MB	Judgeable
String TelephoneGiven up to 10 straight strings between five burrows on a pentagon, find the fewest burrows to move so that no two strings overlap or pass over another burrow.	Medium6	Brute forceGraph+1	No attempts yet	1s	1024 MB	Judgeable
Reverse the Big NumberGiven a string of digit appends and hyphen reversals, find the total X, where each append adds the current string read as a decimal number to X.	Medium6	StringMath+1	No attempts yet	3s	1024 MB	Judgeable
Baeknam's Travel PreparationFor each bag capacity, choose a subset of items with total weight at most the capacity that maximizes the packed value, then output the bag whose value-to-capacity ratio is highest.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	512 MB	Judgeable
Baeknam's Preparation for Travel PreparationGiven moduli A, B, C and remainders a, b, c, find the smallest nonnegative integer satisfying all three congruences, or -1 if none exists.	Medium6	MathNumber theory+2	No attempts yet	3s	512 MB	Judgeable
AaGiven a list of words, decide whether some choice of aa pairs read as one letter Å (sorted after z) makes the whole list sorted.	Medium6	GreedyString+1	No attempts yet	1s	1024 MB	Judgeable
Making Triangles 2Count the number of distinct triangles whose three sides are positive integers summing to n, up to congruence, where each side is a whole number of matchsticks.	Medium6	MathCombinatorics+2	No attempts yet	0.5s	1024 MB	Judgeable
AgingSimulate a priority scheduler with aging: at each step run the available process with highest current priority, breaking ties by running time then index, and report the run order.	Medium6	SimulationHeap+2	No attempts yet	2s	1024 MB	Judgeable
Rescue MissionFor each starting coach, find the shortest prefix of coaches whose prisoner counts can be split into 10 equal nonnegative integer parts; output the prefix length or -1.	Medium6	ArrayMath+2	No attempts yet	2s	1024 MB	Judgeable
OfficesAfter each request adds a new office wired by the stated rules, report the sum of shortest distances from office 0 to every office it can reach.	Medium6	GraphShortest path+1	No attempts yet	2s	1024 MB	Judgeable
Bunch of PaperCount non-decreasing sequences that pick one value from each of N sorted lists of K integers, modulo 1e9+7.	Medium6	Dynamic programmingSorting+2	No attempts yet	2s	512 MB	Judgeable
BruteforceAfter each point update to an array, report the sum over sorted values of floor(b_i * i^k / w), with k and w at most 5, modulo 998244353.	Medium6	SortingBrute force+2	No attempts yet	5s	512 MB	Judgeable
Making a SquareGiven n distinct positive integers, count ordered pairs (i, j) such that a_i^2 + a_j is a perfect square.	Medium6	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Typing ContestChoose a subset of students so that the total effective typing speed is maximized, where each pair's noise f_i and f_j reduces both speeds by s_i f_i f_j.	Medium6	Dynamic programmingSorting+1	No attempts yet	2s	512 MB	Judgeable
Tracking Bio-botsGiven a grid room with horizontal walls, count the squares from which a robot moving only north or east can never reach the northeast exit.	Medium6	IntervalsSorting+1	No attempts yet	2s	1024 MB	Judgeable
Prime SpiralGiven two numbers in the Ulam spiral, find the shortest path between their cells moving only through composite cells, or report impossible.	Medium6	BFSNumber theory+2	No attempts yet	2s	1024 MB	Judgeable
Towers of Powers 2: Power HarderSort M integers given as power towers a1^a2^...^an from smallest to largest, keep input order for equal values, and print each in its original form.	Medium6	SortingMath+1	No attempts yet	2s	1024 MB	Judgeable
Reversing RoadsGiven a directed graph, decide if it is strongly connected; if not, find the earliest input edge whose reversal makes it strongly connected, or report that no single reversal works.	Medium6	GraphDFS+2	No attempts yet	2s	1024 MB	Judgeable
A Careful ApproachGiven up to 8 planes each with a landing window, choose landing times and an order that maximize the smallest gap between consecutive landings.	Medium6	Binary searchGreedy+2	No attempts yet	2s	1024 MB	Judgeable
How Many Subtrees?For each unrooted tree with up to 10 vertices, count how many distinct subtrees (connected subgraphs that are trees) it contains.	Medium6	TreeBrute force+2	No attempts yet	2s	1024 MB	Judgeable
TenCount the rectangular submatrices of a positive-integer matrix whose entries sum to exactly 10, with dimensions up to 300 by 300.	Medium6	Prefix sumTwo pointers+2	No attempts yet	0.5s	1024 MB	Judgeable
Treasure HunterGiven k treasure cells in an m by n grid, find the minimum number of monotone right/down paths from (1,1) to (m,n) that together cover every treasure.	Medium6	SortingGreedy+2	No attempts yet	1s	1024 MB	Judgeable
TrianglesCount triangles formed by n points, no three collinear, that contain at least one other point strictly inside.	Medium6	GeometryCombinatorics+2	No attempts yet	1.2s	1024 MB	Judgeable
Hanoi Tower KGiven n disks on the first peg, print the peg pair moved at step K in the minimal Tower of Hanoi solution.	Medium6	RecursionDivide and conquer+2	No attempts yet	1s	1024 MB	Judgeable
I'm a Final Exam Kind of PersonDistribute 24N study hours across M subjects; subject i starts at a_i, each whole hour adds b_i, capped at 100. Maximize the total score.	Medium6	GreedySorting+2	No attempts yet	1s	1024 MB	Judgeable
Adult GameCount the ways to tile a staircase-like blade shape of N overlapping 2x2 squares with 1x1 and 2x1 dominoes, modulo 1e9+7.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Bitcoin Is God and I Am InvincibleChoose exactly M values from N given numbers, repetition allowed, to maximize the bitwise XOR of the chosen values.	Medium6	Dynamic programmingBit manipulation+1	No attempts yet	1s	1024 MB	Judgeable
CelebrityGiven up to 10000 simple graphs on 5 labeled vertices, count how many have an isomorphism class that occurs exactly once.	Medium6	GraphHash map+2	No attempts yet	1s	1024 MB	Judgeable
Staying HydratedChoose integer coordinates minimizing the sum of Manhattan distances to K axis-aligned rectangles, breaking ties by smallest x then smallest y.	Medium6	MathGreedy+2	No attempts yet	Not set	1024 MB	Judgeable
Fortune From FollyGiven n, k, and success probability p, find the expected number of independent Bernoulli trials until the last n trials contain k successes.	Medium6	ProbabilityDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Hurdle JumpingFor each of T queries on a directed weighted graph, find a path from s to e that minimizes the maximum edge weight, or report -1.	Medium6	GraphSorting+2	No attempts yet	2s	1024 MB	Judgeable
Web Browser 1Simulate a browser's back, forward, access, and compress operations on a bounded cache, then report the current page and the back and forward stacks.	Medium6	SimulationStack+2	No attempts yet	1s	512 MB	Judgeable
Course SwapEach student holds course A_i and wants B_i; two students can swap their courses, and chains of swaps are allowed. Find the minimum number of students who cannot get their desired course.	Medium6	GraphGreedy+2	No attempts yet	4s	512 MB	Judgeable
Team BattleGiven two n-member teams with integer skills, compute the expected value of A's score minus B's score over a uniformly random pairing, where the winner of a match scores the squared skill difference.	Medium6	MathSorting+2	No attempts yet	1s	1024 MB	Judgeable
League of LegendsFor each query range of popularity values, compute the sum of pairwise products of the values in that range.	Medium6	Prefix sumMath+2	No attempts yet	1s	1024 MB	Judgeable
Making a Chip 2Connect N components to at most K power lines, pairing at most two per line without crossing wires, to maximize the total importance and print the assignment.	Medium6	Dynamic programmingIntervals+1	No attempts yet	1s	128 MB	Judgeable
A Sorting ProblemGiven a permutation of 1 to n, you may swap two elements only when their values differ by 1; find the minimum number of such swaps to sort the array.	Medium6	SortingGreedy+2	No attempts yet	3s	1024 MB	Judgeable
MountaineersTwo climbers start at opposite ends of a mountain range of N peaks and must keep equal heights while crossing. Find the minimum total height they travel.	Medium6	Dynamic programmingArray	No attempts yet	2s	1024 MB	Judgeable
WateringEach day water A consecutive pots adding B moisture, then every pot loses 1; find the latest day the first plant can die with optimal watering.	Medium6	GreedySliding window+2	No attempts yet	1s	512 MB	Judgeable
Escape RoomOn a grid of digits where 0 cells are walls, find two reachable cells whose shortest-path distance is maximum and report the largest sum of their digits, or 0 if none exists.	Medium6	BFSGraph+2	No attempts yet	1s	512 MB	Judgeable
Buffered BuffetPlace n people around a circular table, each with a minimum required distance to every other person measured along the circumference, and find the smallest possible circumference.	Medium6	GreedySorting+2	No attempts yet	1s	1024 MB	Judgeable
Candy ContributionGiven an undirected graph where crossing a border costs a percentage of candies rounded up, find the maximum candies reachable from start to home.	Medium6	GraphShortest path+2	No attempts yet	3s	1024 MB	Judgeable
git mvGiven two Unix paths, output the shortest string of the form A{B => C}D that rewrites the source path into the destination path.	Medium6	StringImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Kudzu KnivingGiven the age of a kudzu tree whose vertices double each year, report for each requested root how many vertices its subtree holds, modulo 1e9+7, accounting for earlier removals.	Medium6	MathTree+2	No attempts yet	3s	1024 MB	Judgeable
Monarchy in VertigoProcess births and deaths in a royal family tree, and after each death report the living person found by a preorder walk from the root that visits children before siblings and older before younger.	Medium6	TreeDFS+2	No attempts yet	1s	1024 MB	Judgeable
KamenčićiTwo players take pebbles from either end of a row until one collects k red pebbles and loses. Decide whether the first player can force a win.	Medium6	Game theoryDynamic programming+1	No attempts yet	1s	512 MB	Judgeable
Boxes on a ShelfChoose which boxes to place on a shelf of length L so that each box's center lies strictly inside the shelf, maximizing the count.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Two SlicersTwo slicers cut a unit circular cake into a and b equal sectors; rotate one relative to the other to minimize the gap between the largest and smallest of the a+b pieces, and print that gap as an irreducible fraction.	Medium6	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Accelerometer calibrationRecover each accelerometer's sinusoidal error model from four calibration readings, then invert the two readings to compute the device rotation angle.	Medium6	MathGeometry+1	No attempts yet	1s	256 MB	Judgeable
Painting roofsGiven a grid of two colors, recolor the fewest cells so that the grid becomes bipartite by parity, i.e. every side-adjacent pair differs.	Medium6	GraphMatrix+2	No attempts yet	1s	256 MB	Judgeable
Mr. Panda and TypewriterFind the minimum total time to type string S by appending single characters, copying substrings to a clipboard, and pasting the clipboard with costs X, Y, and Z.	Medium6	Dynamic programmingString	No attempts yet	10s	512 MB	Judgeable
Spiral MatrixCount the paths that visit every cell of an n x m grid exactly once, where each move goes straight or turns only right.	Medium6	CombinatoricsSimulation	No attempts yet	1s	256 MB	Judgeable
CityCount the segments whose endpoints and midpoint are all grid points of an (n+1) by (m+1) lattice.	Medium6	MathNumber theory+2	No attempts yet	1s	256 MB	Judgeable
Construct PointsOutput four integer points within 10^9 whose two lines meet at a point whose coordinates exceed 10^27 in absolute value.	Medium6	MathGeometry+2	No attempts yet	1s	1024 MB	Judgeable
AuntsGiven altitude reports on an A by B grid where adjacent cells differ by exactly 1, find the first report that makes a consistent assignment impossible.	Medium6	MathSorting+1	No attempts yet	7s	128 MB	Judgeable
Divisible InversionsGiven a permutation of 1 to n, count pairs i < j where p[i] is a multiple of p[j].	Medium6	ArrayMath+2	No attempts yet	2s	512 MB	Judgeable
Negative BaseFind the integer of least absolute value whose negabinary (base -2) representation contains at least k consecutive zeroes, breaking ties by shortest representation.	Medium6	MathBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Same SongsRemove songs from a fixed playlist so that the remaining list has the maximum number of adjacent equal pairs, and output one such list.	Medium6	Dynamic programmingGreedy+2	No attempts yet	2s	512 MB	Judgeable
Template for SearchGiven a template of lowercase letters, ?, and *, find the shortest lowercase palindrome that matches it, or print -1 if none exists.	Medium6	StringDynamic programming	No attempts yet	1s	256 MB	Judgeable
Easy EquationCount the number of positive integer 5-tuples (x,y,z,w,t) with x^5 + y^4 + z^3 + w^2 + t = n, for n up to 1e9.	Medium6	MathBrute force+2	No attempts yet	1s	64 MB	Judgeable
HeraclesFind the shortest closed walk from city 1 that visits each of the 12 required cities at least once and returns to city 1, in a weighted undirected graph.	Medium6	GraphShortest path+2	No attempts yet	2s	64 MB	Judgeable
MedicineCount the ways to remove 3N packets from either end when the morning and evening packets are interchangeable but the noon packet is fixed.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	1s	512 MB	Judgeable
Young Energy Is Not EnoughPartition 3N ages into N triples; each triple's energy is its median age. Minimize the spread between the largest and smallest median.	Medium6	SortingGreedy+2	No attempts yet	1s	256 MB	Judgeable
Making a DigramPlace one of the seven-square digram shapes on an n by m grid to minimize the cost of adding and erasing cells so the black cells match the shape.	Medium6	Brute forceImplementation+2	No attempts yet	1s	256 MB	Judgeable
1, 2, 3, 4For each test case, count the distinct sums obtainable from up to a copies of 1, b copies of 2, c copies of 3, and d copies of 4.	Medium6	MathGreedy	No attempts yet	1s	256 MB	Judgeable
Double RainbowGiven a color sequence and k colors, find the shortest contiguous block that contains every color and whose complement also contains every color, or print 0.	Medium6	Two pointersSliding window+2	No attempts yet	1s	1024 MB	Judgeable
TrioCount the sets of three numbers from a list of four-digit numbers (no zero digits) where each digit position is either all equal or all distinct across the three.	Medium6	Hash mapCombinatorics+1	No attempts yet	2s	1024 MB	Judgeable
CabbageEach child eats only one cabbage variety; given initial stocks, per-variety prices, and a shared budget, find the largest equal portion each child can receive.	Medium6	Binary searchGreedy+2	No attempts yet	1s	256 MB	Judgeable
Chinese Remainder TheoremGiven pairs (a_i, b_i), find the largest m such that a_i is congruent to b_i modulo m for every i; since a_i >= b_i, m must divide all differences a_i - b_i.	Medium6	Number theoryMath+2	No attempts yet	1s	256 MB	Judgeable
Baking PansFor each of up to 1000 triples of pan areas, decide whether two circular cakes from the first two pans fit inside the third pan with a nonzero gap between them.	Medium6	GeometryMath+2	No attempts yet	1s	256 MB	Judgeable
Identical ScarvesGiven n scarf lengths and k moments (one row knit or unravelled per moment), find the largest count of scarves that can be made equal in length within k total operations.	Medium6	SortingGreedy+2	No attempts yet	1s	256 MB	Judgeable
Cookie Run: KingdomGiven which resource types each building produces and which resources each unbuilt building needs, count the buildings constructible within T seconds starting from the M already-built ones.	Medium6	GraphBFS+2	No attempts yet	1s	512 MB	Judgeable
Fire Behind Leaf VillageGiven a grid of trees, stones, and fires, find the day when all fires that can meet have merged and the number of burning cells at that moment.	Medium6	BFSSimulation+1	No attempts yet	2s	512 MB	Judgeable
Fizz and BuzzGiven a sequence of numbers each divisible by 3 or 5, guess for each position whether Fizz (divisible by 3) or Buzz (divisible by 5) produced it, allowing at most 1200 errors.	Medium6	ProbabilityMath+2	No attempts yet	2s	256 MB	Judgeable
Red-Black TreeColor the vertices of a binary rooted tree red or black so no red-red edge exists and every root-to-void path has the same black count, or say Impossible.	Medium6	Dynamic programmingTree+1	No attempts yet	2s	1024 MB	Judgeable
Interstellar FantasyGiven a sphere obstacle and two points outside or on it, find the shortest path length from s to t that never enters the sphere.	Medium6	GeometryMath+2	No attempts yet	1s	256 MB	Judgeable
Moves You Need to MakeGiven a permutation, find the fewest moves to sort it using adjacent swaps plus at most one swap of the first and last elements.	Medium6	ArrayMath+1	No attempts yet	2s	512 MB	Judgeable
MagnetiCount the ways to place n magnets with radii r_i on l slots so that each pair of neighboring magnets is at least max(r_i, r_j) cm apart, modulo 1e9+7.	Medium6	Dynamic programmingCombinatorics+1	No attempts yet	1s	512 MB	Judgeable
Chiaki ChainDecide whether a given graph is a k-th order Chiaki Chain: a main chain with k sub-chains, each ending in a simple cycle of length 3 to k+2.	Medium6	GraphTopological sort+1	No attempts yet	1s	256 MB	Judgeable
Juke ArtemGiven a tree and a permutation on its vertices, find the minimum total cost of edge swaps needed to put every number in its place.	Medium6	TreeGreedy+1	No attempts yet	2s	512 MB	Judgeable
Guessing AnswersGiven the correct answers and the set of problems guessed correctly, build an answer sequence where consecutive answers differ and exactly the listed problems are correct.	Medium6	GreedyImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Miswritten DFSGiven a binary tree and a huge K, find the K-th node visited by a buggy pre-order DFS that recurses into the left child twice, without simulating all visits.	Medium6	TreeDFS+2	No attempts yet	1s	1024 MB	Judgeable
Reorganizing Bus RoutesMerge overlapping intervals into their union, keeping the cheaper fare, then output the surviving intervals sorted by start.	Medium6	SortingIntervals+2	No attempts yet	2s	1024 MB	Judgeable
Escape RoomGiven N rooms with per-room exit costs and M candidate warps with costs, choose warps and exits so every room reaches the outside, minimizing the total installation time.	Medium6	Minimum spanning treeGraph+2	No attempts yet	2s	1024 MB	Judgeable
What Was My Rank??Given students' scores and some remembered grade orderings, decide for each query whether one student's final grade is higher, lower, equal, or undetermined.	Medium6	GraphBFS+1	No attempts yet	1s	1024 MB	Judgeable
String DecompressionGiven patterns mapped to uppercase letters and a compressed string, expand it and print characters S through E of the original string.	Medium6	StringImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Children and Gift BoxesGiven N boxes of gifts and M children with desired amounts in a fixed order, decide if each child in turn can take their amount from the currently fullest box.	Medium6	GreedyHeap+2	No attempts yet	1s	1024 MB	Judgeable
Picky Children and Gift BoxesEach child in order takes w_i gifts from the box ranked b_i-th largest by current count; decide if every child can succeed.	Medium6	SortingGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Forming Badminton Doubles TeamsPartition some people into groups of four to minimize the total skill gap per group, and list anyone left out; output any valid choice.	Medium6	SortingDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Glossary ArrangementSplit a sorted list of filenames into columns of variable height so the table fits in width w using the fewest lines.	Medium6	Dynamic programmingBinary search+1	No attempts yet	5s	1024 MB	Judgeable
Cyanide RiversGiven a binary string whose first and last digits are 1, each 0 needs a neighboring tower certified at least one day earlier; find the minimum number of days to certify all towers.	Medium6	GreedyDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Two-Step Shortest Path 1Given a weighted directed graph, find the shortest X to Z distance that passes through vertex Y and the shortest one that avoids Y.	Medium6	GraphShortest path+2	No attempts yet	0.3s	512 MB	Judgeable
Two-Step Shortest Path 2Given an undirected weighted graph, find the shortest distance from X to Z that passes through at least one of P given intermediate vertices.	Medium6	GraphShortest path+2	No attempts yet	1s	512 MB	Judgeable