Interview warm-up

Short whiteboard warmups

Under construction

Still being built. Things may change

Total results4,880 problems

Triangle
Medium4
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Seed Bags
Medium4
Brute force, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Checkpoint
Medium4
BFS, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bags
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bomb
Medium4
Shortest path, BFS
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Exam
Medium4
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Greedy Scheduler
Medium4
Heap, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Spaces
Medium4
Dynamic programming, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Trail
Medium4
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Treasure
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Colored paper craft
Medium4
BFS, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Piggy Bank
Medium4
Bit manipulation, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Increasing Median Sequence
Medium4
Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
XOR Hashing
Medium4
Probability, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Toys
Medium4
String, Hash map
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Palindrome
Medium4
String, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Remote Work
Medium4
Sorting, Greedy
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Gifts
Medium4
Math, Greedy+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Pawns
Medium4
Matrix, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Digit Sum Process
Medium4
Simulation, Sorting+1
No attempts yet
Time limit
30s
Memory limit
1024 MB
Judgeable
Qualification threshold
Medium4
Sorting, Prefix sum+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Speedrun
Medium4
Graph, DFS
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Stock Price Records
Medium4
Array, Prefix sum
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Estate
Medium4
Math, Greedy
No attempts yet
Time limit
15s
Memory limit
1024 MB
Judgeable
Walks on a binary tree
Medium4
Tree, Math
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Colorful Snake
Medium4
Simulation, Hash map+1
No attempts yet
Time limit
32s
Memory limit
1024 MB
Judgeable
Druk
Medium4
Math, String matching
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Kinomani
Medium4
Greedy, Intervals+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Competition Hall
Medium4
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Translation
Medium4
Hash map, String
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Miniröj
Medium4
Dynamic programming, Array
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Buying Books
Medium4
Brute force, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Library
Medium4
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Backward Digit Sums
Medium4
Backtracking, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DNA Assembly
Medium4
Brute force, String matching
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Cow Prom
Medium4
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dollar Dayz
Medium4
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Water Bowls
Medium4
Bit manipulation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
City Skyline
Medium4
Stack, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Moo University Team Tryouts
Medium4
Brute force, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Lying Livestock
Medium4
Graph, Topological sort+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cow Parade
Medium4
Simulation, Hash map
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fence Height
Medium4
Sorting, Sliding window+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Big Game
Medium4
Greedy, Prefix sum
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sweet Butter
Medium4
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Golf
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bonbons
Medium4
Math, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Six Degrees of Cowvin Bacon
Medium4
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pasture Fences
Medium4
Prefix sum, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dessert
Medium4
Backtracking, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Card Drawing
Medium4
Hash map, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stamps
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gift Giving
Medium4
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Building Blocks
Medium4
Sorting, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cow Calisthenics
Medium4
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Equal Summed Subsets
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Garage Sailing
Medium4
Dynamic programming, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ordered Fractions
Medium4
Number theory, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Subset Sums
Medium4
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Score Inflation
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Lazy to Win
Medium4
Sliding window, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
kex
Medium4
Binary search, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Donut Planet
Medium4
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Meeting
Medium4
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Chaotic Partitions
Medium4
Backtracking, Recursion+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Square-Free Pairs
Medium4
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sum
Medium4
Backtracking, Recursion+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Arrangements Without Steep Descents
Medium4
Backtracking, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dyck Paths
Medium4
Simulation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Candies for first graders
Medium4
Math, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fibonacci Sums
Medium4
Backtracking, Recursion
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Prizes
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Diagonal Numbering
Medium4
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sum of Minimums
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Talent Show
Medium4
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Camp Circular Bus
Medium4
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Selfish Parallel Bar Exercise (Easy)
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Meeting in Manhattan
Medium4
Sorting, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Time Moves Again
Medium4
Greedy, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mini BINGO
Medium4
Backtracking, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Chamsalgi Road
Medium4
Sorting, Simulation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
MazeMan
Medium4
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Toll Roads
Medium4
Union-find, Minimum spanning tree+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Matrix
Medium4
Hash map, Prefix sum
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Padovan Sequence 2
Medium4
Matrix, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stop Saying That Flag Line
Medium4
Greedy, Prefix sum
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Love Revolution
Medium4
Minimum spanning tree, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Coin Collecting 2
Medium4
Math, Brute force+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Vrsta
Medium4
Segment tree, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Creative Accounting
Medium4
Prefix sum, Brute force+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Everything Is A Nail
Medium4
Dynamic programming, Implementation
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Beppa and SwerChat
Medium4
Greedy, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Road To Savings
Medium4
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Solitaire
Medium4
Simulation, Implementation
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Town
Medium4
Math, Binary search+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Two covers
Medium4
Array, Prefix sum+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Boredom Buster (Hard)
Medium4
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gems in the maze
Medium4
Graph, DFS+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Easy representation
Medium4
String, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Adding the Exponents
Medium4
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
TriangleGiven side lengths of two triangles, decide whether one straight cut of a rectangle, followed by rotating and flipping the pieces, can produce both triangles.	Medium4	GeometryMath+1	No attempts yet	1s	1024 MB	Judgeable
Seed BagsGiven a garden grid with marked cells, find the fewest 3x3 seed bags, each centered on a garden cell, that cover every marked cell.	Medium4	Brute forceMatrix+1	No attempts yet	1s	1024 MB	Judgeable
CheckpointFind the length of the shortest path that starts at S, visits checkpoints 1 through d in order, and ends at E in a maze grid.	Medium4	BFSShortest path+1	No attempts yet	1s	1024 MB	Judgeable
BagsFor each data set, find the fewest items whose weights sum exactly to the target, or report Not possible if no such subset exists.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
BombGiven 3D mazes where each destructible wall costs one bomb, find the fewest bombs needed to get from S to E.	Medium4	Shortest pathBFS	No attempts yet	1s	1024 MB	Judgeable
ExamGiven your answers and your friend's answers on a true/false exam, find the most questions you could have gotten right if the friend scored k.	Medium4	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Greedy SchedulerAssign each customer to the cashier who becomes free first, breaking ties by the smaller cashier number, and print that cashier's number for each customer.	Medium4	HeapGreedy+1	No attempts yet	1s	1024 MB	Judgeable
SpacesGiven a dictionary and a string with its spaces removed, output the zero-based indices where spaces belong so the string splits into dictionary words.	Medium4	Dynamic programmingString+1	No attempts yet	1s	1024 MB	Judgeable
TrailGiven a grid where entering land, forest, or water costs 3, 5, or 8 days, find the fastest route to the far left column and compare it with the deadline.	Medium4	Shortest pathGraph+1	No attempts yet	1s	1024 MB	Judgeable
TreasureGiven items with values and weights and a capacity, the task finds the maximum total value of items that fit in one trip, for several data sets.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Colored paper craftGiven a grid of letters, decide whether every connected region of equal letters forms a filled rectangle.	Medium4	BFSMatrix+1	No attempts yet	1s	1024 MB	Judgeable
Piggy BankGiven n coins worth 2 raised to each a_i, find the largest exponent b such that a coin worth 2^b can be made by exchanging coins.	Medium4	Bit manipulationMath	No attempts yet	2s	1024 MB	Judgeable
Increasing Median SequenceGiven three subject scores per exam, decide whether changing at most one score per exam can make the sequence of medians strictly increase.	Medium4	Greedy	No attempts yet	1s	1024 MB	Judgeable
XOR HashingEach hash value 0 to 2^N-1 is equally likely for a random point, and the task asks for the chance that M random picks contain two with the same value, modulo 10^9+7.	Medium4	ProbabilityMath+1	No attempts yet	1s	1024 MB	Judgeable
ToysGiven two equal-length strings, decides whether reversing odd-length substrings can turn the first into the second.	Medium4	StringHash map	No attempts yet	1s	1024 MB	Judgeable
PalindromeGiven a string of a and b, find the fewest adjacent swaps that turn it into a palindrome, or -1 if that is impossible.	Medium4	StringGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Remote WorkPick the start hour of a one-hour meeting that minimizes total overtime, given each employee's work window [A_i, B_i].	Medium4	SortingGreedy	No attempts yet	0.5s	1024 MB	Judgeable
GiftsSplit candy packages numbered 1 to N into the largest number of children who each receive the same total candy count.	Medium4	MathGreedy+1	No attempts yet	5s	1024 MB	Judgeable
PawnsGiven a board of pawns that move any distance along a row or column, find the fewest moves needed to gather all pawns onto one square.	Medium4	MatrixImplementation	No attempts yet	1s	1024 MB	Judgeable
Digit Sum ProcessFor each query M up to 5e9, decide whether M appears in the sequence 1, g(1), g(g(1)), ... where g(n) = n + (digit sum of n)^2.	Medium4	SimulationSorting+1	No attempts yet	30s	1024 MB	Judgeable
Qualification thresholdGiven N problem scores and Q thresholds, find for each threshold the fewest problems to solve, taking the highest-scoring ones first.	Medium4	SortingPrefix sum+1	No attempts yet	5s	1024 MB	Judgeable
SpeedrunGiven N levels where each level points to a next level, find the minimum total time (sum of level numbers) to complete levels until entering a completed one.	Medium4	GraphDFS	No attempts yet	6s	1024 MB	Judgeable
Stock Price RecordsFor each K, count the segments of K consecutive days in which the share price rose strictly every day.	Medium4	ArrayPrefix sum	No attempts yet	1s	1024 MB	Judgeable
EstateGiven a range of house numbers from A to B, find the largest sum of decimal digits of any number in that range.	Medium4	MathGreedy	No attempts yet	15s	1024 MB	Judgeable
Walks on a binary treeGiven Q queries on a binary tree numbered level by level (node values up to 10^18), print the edge distance between each pair of nodes.	Medium4	TreeMath	No attempts yet	20s	1024 MB	Judgeable
Colorful SnakeSimulate a snake that moves on an m by m board, eats colored snacks, and report the color of the segment in a queried cell after each query.	Medium4	SimulationHash map+1	No attempts yet	32s	1024 MB	Judgeable
DrukFind every stencil length k that tiles the n by m letter grid exactly, with horizontal and vertical stencils spelling the same text.	Medium4	MathString matching	No attempts yet	4s	1024 MB	Judgeable
KinomaniGiven N film screening intervals, find the fewest members needed to cover every film with non-overlapping viewings, and list each member's films.	Medium4	GreedyIntervals+2	No attempts yet	4s	1024 MB	Judgeable
Competition HallGiven N participants on an axis-aligned unit grid with walls at least 1 away, find the minimum area of the hall.	Medium4	MathBrute force	No attempts yet	1s	1024 MB	Judgeable
TranslationGiven a word-pair dictionary and a text, print the text after repeatedly translating A to B and back to A until it stops changing.	Medium4	Hash mapString	No attempts yet	4s	1024 MB	Judgeable
MiniröjGiven the bottom row of a 2xN Minesweeper board with its clue numbers, label each top cell as safe, certain mine, or undetermined.	Medium4	Dynamic programmingArray	No attempts yet	3s	1024 MB	Judgeable
Buying BooksGiven N books sold at up to 15 stores, each with a postage fee, find the minimum total cost of buying every book, postage included.	Medium4	Brute forceBit manipulation	No attempts yet	1s	1024 MB	Judgeable
LibraryGiven N shelf positions on a line and a carry limit K, find the minimum total distance walked from 0 to return all books.	Medium4	GreedySorting+1	No attempts yet	1s	1024 MB	Judgeable
Backward Digit SumsGiven N and a target sum, find the lexicographically smallest permutation of 1 to N whose repeated adjacent-sum reduction ends at that sum.	Medium4	BacktrackingBrute force	No attempts yet	1s	1024 MB	Judgeable
DNA AssemblyGiven N DNA fragments (2 to 7 strings, each 1 to 7 characters), find the shortest string that merges all of them using maximal end-to-start overlaps.	Medium4	Brute forceString matching	No attempts yet	1s	1024 MB	Judgeable
The Cow PromGiven N cows and M directed ropes, count the groups of two or more cows where every cow can reach every other cow along the ropes.	Medium4	GraphDFS	No attempts yet	1s	1024 MB	Judgeable
Dollar DayzCount the ways to spend exactly N dollars on unlimited tools priced $1 to $K, where the order of purchases does not matter.	Medium4	Dynamic programming	No attempts yet	1s	1024 MB	Judgeable
The Water BowlsGiven 20 bowls in a row, each 0 or 1, find the fewest flips (each flip toggles a bowl and its neighbors) that make every bowl 0.	Medium4	Bit manipulationBrute force+1	No attempts yet	1s	1024 MB	Judgeable
City SkylineGiven N points where a city skyline changes height, find the minimum number of box-shaped buildings that produce that skyline.	Medium4	StackGreedy	No attempts yet	1s	1024 MB	Judgeable
Moo University Team TryoutsGiven N calves with heights and weights, find the largest team where every calf satisfies A(H-h)+B(W-w)<=C, with h and w the team's minimum height and weight.	Medium4	Brute forceSorting+1	No attempts yet	1s	1024 MB	Judgeable
Lying LivestockFor each cow, check whether the other cows' statements about food amounts can all be true, and count the cows that pass.	Medium4	GraphTopological sort+1	No attempts yet	1s	1024 MB	Judgeable
Cow ParadeGiven D directions with block counts on a city grid, count the distinct streets the cows walk on, where a street walked twice counts once.	Medium4	SimulationHash map	No attempts yet	1s	1024 MB	Judgeable
Fence HeightGiven cow height preferences, find the narrowest range of post heights that covers strictly more than half of the cows' preferences.	Medium4	SortingSliding window+1	No attempts yet	1s	1024 MB	Judgeable
The Big GameSplit a line of N cows marked J or H into the fewest contiguous buses so each bus has a Jersey-Holstein gap of at most I, unless it is one-sided.	Medium4	GreedyPrefix sum	No attempts yet	1s	1024 MB	Judgeable
Sweet ButterFind the pasture whose total shortest-path distance from all cow pastures is smallest, counting each cow separately.	Medium4	Shortest pathGraph+1	No attempts yet	1s	1024 MB	Judgeable
GolfGiven a distance D and C club distances, find the fewest strokes that sum to exactly D, or 0 if impossible.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
BonbonsGiven N cows in a circle where every second remaining cow leaves, find the number of the last cow standing.	Medium4	MathSimulation	No attempts yet	1s	1024 MB	Judgeable
Six Degrees of Cowvin BaconFind the cow with the smallest average degree of separation to the others in a graph built from movie casts, and print 100 times that mean.	Medium4	Shortest pathGraph	No attempts yet	1s	1024 MB	Judgeable
Pasture FencesGiven N signed pole labels, find the longest contiguous segment whose sum has the smallest absolute value, and report its endpoints and that absolute sum.	Medium4	Prefix sumArray+1	No attempts yet	1s	1024 MB	Judgeable
DessertInsert +, -, or . between cows numbered 1 to N so the expression evaluates to 0, then list the first 20 expressions and count all of them.	Medium4	BacktrackingBrute force+1	No attempts yet	1s	1024 MB	Judgeable
Card DrawingGiven N cards with values, count the nonempty subsets of cards whose values are all distinct, modulo 10^9+7.	Medium4	Hash mapCombinatorics	No attempts yet	1s	1024 MB	Judgeable
StampsGiven stamp values and a limit on how many stamps fit on an envelope, find the longest run of consecutive postage values that can be made.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Gift GivingAssign one gift to each cow from her wish list so that the most cows are pleased, given the limited copies of each gift.	Medium4	GraphDFS	No attempts yet	1s	1024 MB	Judgeable
Building BlocksGiven blocks that may be rotated, find the height of the tallest tower where each block fits within the width and length of the block below.	Medium4	SortingDynamic programming	No attempts yet	1s	1024 MB	Judgeable
Cow CalisthenicsFind the length of the shortest directed cycle in a weighted graph with at most 400 points and 2000 directed edges.	Medium4	Shortest pathGraph	No attempts yet	1s	1024 MB	Judgeable
Equal Summed SubsetsCount the ways to split {1, ..., N} into two disjoint subsets with equal sums, counting a swapped pair once.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Garage SailingPick at most K of N objects to maximize the total gap between market value and garage sale price, and print that maximum profit.	Medium4	Dynamic programmingSorting	No attempts yet	1s	1024 MB	Judgeable
Ordered FractionsGiven N, count the reduced fractions between 0 and 1 with denominators up to N, then print them all in increasing order.	Medium4	Number theorySorting	No attempts yet	1s	1024 MB	Judgeable
Subset SumsCount the ways to split the integers 1 to N into two subsets with equal sums, where swapping the two subsets gives the same partition.	Medium4	Dynamic programmingCombinatorics	No attempts yet	1s	1024 MB	Judgeable
Score InflationGiven a contest length of M minutes and N problem categories with points and solve times, find the maximum total points using unlimited problems from each category within M minutes.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Lazy to WinGiven the point values of n problems, find the fewest consecutive problems, skipping at most one, needed to reach at least half of the total score.	Medium4	Sliding windowPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
kexGiven a set A and several values k, find for each k the k-th smallest non-negative integer that is not in A.	Medium4	Binary searchSorting+1	No attempts yet	2s	1024 MB	Judgeable
Donut PlanetCount the connected regions of empty cells on an N by M grid whose opposite edges wrap around, so the grid acts as a torus.	Medium4	GraphBFS+1	No attempts yet	1s	1024 MB	Judgeable
MeetingGiven the personalities of students from two universities, find non-crossing handshake pairs that maximize the total satisfaction W[a][b].	Medium4	Dynamic programming	No attempts yet	1s	512 MB	Judgeable
Chaotic PartitionsGiven n, list every partition of n into distinct increasing summands where no three consecutive summands form an arithmetic progression.	Medium4	BacktrackingRecursion+1	No attempts yet	1s	1024 MB	Judgeable
Square-Free PairsCount pairs a < b in the range [l, r] where a, b, and their product ab are all square-free, with r - l at most 1000.	Medium4	Number theoryMath+1	No attempts yet	1s	1024 MB	Judgeable
SumList every sequence of k integers that sums to n, where adjacent terms differ by at most 1, in lexicographic order.	Medium4	BacktrackingRecursion+1	No attempts yet	1s	1024 MB	Judgeable
Arrangements Without Steep DescentsPrint every ordered selection of k distinct numbers from 1 to n where no adjacent pair drops by more than 1, sorted lexicographically.	Medium4	BacktrackingCombinatorics	No attempts yet	1s	1024 MB	Judgeable
Dyck PathsGiven a correct bracket sequence, draw its Dyck path on a grid of unit squares using / and \ with the fewest possible lines.	Medium4	SimulationString	No attempts yet	1s	1024 MB	Judgeable
Candies for first gradersGiven n, a, and b, find how many candies Andrei and Anya each buy so the total leaves the smallest remainder mod n, with ties going to the largest x.	Medium4	MathGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Fibonacci SumsFind every way to write n as a sum of Fibonacci numbers 1, 2, 3, 5, ... in non-decreasing order, using each value at most k times.	Medium4	BacktrackingRecursion	No attempts yet	1s	1024 MB	Judgeable
PrizesGiven prize values in order, find the maximum sum of a subsequence whose values are strictly increasing.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Diagonal NumberingGiven an r by c table numbered along upper-right to lower-left diagonals, find the row and column of each of q given cell numbers.	Medium4	MathImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Sum of MinimumsSplit an array of n numbers into k contiguous parts so the sum of each part's minimum is as large as possible, and output the split points.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Talent ShowGiven N skill levels, arrange the soldiers so that the first full skill plus each rise over the previous performer totals as much as possible.	Medium4	GreedySorting	No attempts yet	1s	1024 MB	Judgeable
Camp Circular BusFind when the last soldier alights from a circular bus that never stops, where each soldier boards at the first bus pass after their wait starts.	Medium4	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Selfish Parallel Bar Exercise (Easy)Split N trainees into M contiguous groups to maximize the sum, over all groups, of the strengths of each group's tallest members.	Medium4	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Meeting in ManhattanGiven M points in N dimensions, find a point that minimizes the total Manhattan distance to all of them, and print that minimum sum and the point.	Medium4	SortingMath	No attempts yet	1s	1024 MB	Judgeable
Time Moves AgainGiven obstacle arrival times, decide whether uses of the power with lengths 1, 2, 3, ... and i-second cooldowns can cover every obstacle.	Medium4	GreedySimulation	No attempts yet	1s	1024 MB	Judgeable
Mini BINGOGiven a 3x3 letter grid and a seed order, find the lexicographically smallest order that yields the same per-cell BINGO score string.	Medium4	BacktrackingImplementation	No attempts yet	1s	512 MB	Judgeable
Chamsalgi RoadGiven a road of n meters with k traffic lights at integer positions, each on a red-green cycle, find the total time for a car moving at 1 m/s to reach the end.	Medium4	SortingSimulation+1	No attempts yet	1s	512 MB	Judgeable
MazeManFind the fewest maze entrances needed to eat all reachable dots, and count the dots that no entrance can reach.	Medium4	GraphBFS+1	No attempts yet	1s	1024 MB	Judgeable
Toll RoadsFor each city pair, find the lowest possible maximum toll on a route between them and the number of cities reachable from the first city under that toll.	Medium4	Union-findMinimum spanning tree+1	No attempts yet	3s	1024 MB	Judgeable
MatrixSupport range +1 updates on single rows and point queries on an N by M matrix with N, M up to 1e18, handled online.	Medium4	Hash mapPrefix sum	No attempts yet	1.5s	1024 MB	Judgeable
Padovan Sequence 2Given N up to 10^18, compute P(N) modulo 998244353, where each term is the sum of the terms two and three positions before it.	Medium4	MatrixDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Stop Saying That Flag LineFind the fewest shouts, each adding a boost that shrinks with distance from the shouter's spot, so every minion reaches its target strength.	Medium4	GreedyPrefix sum	No attempts yet	1s	1024 MB	Judgeable
Love RevolutionRemove the cheapest set of unestablished relationships so that no cycle remains, keeping all established ones, and report the minimum total affection lost.	Medium4	Minimum spanning treeGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Coin Collecting 2Aoi flips one row and Rin flips one column, each trying to collect more coins. Find both players' counts under optimal play.	Medium4	MathBrute force+1	No attempts yet	2s	1024 MB	Judgeable
VrstaAfter each statement adds a_i students of height v_i, output the height of the middle student, choosing the shorter one when the count is even.	Medium4	Segment treeSorting+1	No attempts yet	1s	1024 MB	Judgeable
Creative AccountingGiven daily profits and a range of segment sizes, find the minimum and maximum count of profitable segments over all sizes and starting days.	Medium4	Prefix sumBrute force+1	No attempts yet	5s	1024 MB	Judgeable
Everything Is A NailGiven a sequence of nail, screw, and bolt tasks, find the most tasks you can complete when switching tools permanently loses the old one.	Medium4	Dynamic programmingImplementation	No attempts yet	5s	1024 MB	Judgeable
Beppa and SwerChatGiven two recorded orderings of n members, find the minimum number of members who must have gone online between the two snapshots.	Medium4	GreedyTwo pointers+1	No attempts yet	2s	1024 MB	Judgeable
Road To SavingsGiven a road network, find the total length of roads that lie on no shortest path between the mayor's house a and office b.	Medium4	Shortest pathGraph	No attempts yet	1s	1024 MB	Judgeable
SolitaireGiven a shuffled deck of 4n cards across four suits, count how many passes through the deck are needed to place every card on its suit slot.	Medium4	SimulationImplementation	No attempts yet	3s	1024 MB	Judgeable
TownGiven how many of each digit 0 to 9 you have, find the largest x such that the numbers 1 through x can all be written with those digits.	Medium4	MathBinary search+1	No attempts yet	1s	1024 MB	Judgeable
Two coversCount positions x that lack both a piece reaching k letters left of x and a different piece reaching k letters right of x.	Medium4	ArrayPrefix sum+1	No attempts yet	3s	1024 MB	Judgeable
Boredom Buster (Hard)Split an integer into two parts until n ones remain, earning the product of the parts at each split. Find the maximum hazelnuts.	Medium4	MathCombinatorics	No attempts yet	1s	1024 MB	Judgeable
Gems in the mazeFind the longest run of distinct chambers reachable by repeatedly following the tunnel from v to (av^2 + bv + c) mod n.	Medium4	GraphDFS+1	No attempts yet	3s	2048 MB	Judgeable
Easy representationGiven a correct bracket sequence, find the area of the black regions in its geometric representation, where regions alternate colors starting with black outside.	Medium4	StringMath	No attempts yet	1s	1024 MB	Judgeable
Adding the ExponentsGiven N distinct primes and K up to 10^12, find the sum over i from 1 to K of how many times the primes in P divide i, counted with multiplicity.	Medium4	Number theoryMath	No attempts yet	1s	128 MB	Judgeable