Problems

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Total results29,450 problems

Youngest Boss
Medium5
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Short Story Contest
Medium5
Greedy, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Focus
Medium5
Greedy, Intervals+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Laser Sculpting
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Erasing and Winning
Medium5
Greedy, Stack+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Winner of the Bubble Game
Medium5
Combinatorics, Game theory+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Vampires
Medium5
Probability, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
University Course
Medium5
Topological sort, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sentence Reduction
Medium5
Dynamic programming, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Strange Bar
Medium5
Binary search, Array+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sum Decomposition 2
Medium5
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Good Positions in a Permutation
Medium5
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Making the Array Palindromic
Medium5
Two pointers, Greedy+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Postal Delivery
Medium5
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Alphabet String
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Minimum number of islands
Medium5
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Project Panoptes
Medium5
Array, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Make One Square
Medium5
Geometry, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Chinese Classics
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Two-Wheel Buggy
Medium5
Geometry, Simulation+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
For the Peace
Medium5
Greedy, Implementation
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Champernowne Constant
Medium5
Math, String matching+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Space Coconut Crab II
Medium5
Math, Number theory
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Autocorrelation Function
Medium5
Math, Geometry+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Gather on the Clock
Medium5
Dynamic programming, Intervals
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Letters
Medium5
Combinatorics, Math
No attempts yet
Time limit
0.2s
Memory limit
256 MB
Judgeable
Cutting into three pieces
Medium5
String, Brute force+1
No attempts yet
Time limit
0.2s
Memory limit
256 MB
Judgeable
m-ary Partitions
Medium5
Dynamic programming, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
A Rational Sequence 3
Medium5
Tree, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Smoothed Gardens
Medium5
Geometry, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Robot
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Opening Day 2
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Assignments
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Tax
Medium5
Shortest path, Graph+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Password
Medium5
Combinatorics, Math
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Grand Opening
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
It's Raining, Man
Medium5
Graph, DFS
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jupiter Orbiter
Medium5
Simulation, Queue+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Key Knocking
Medium5
Greedy, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Within Arm's Reach
Medium5
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Binomial coefficient queries
Medium5
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Abbreviation
Medium5
String, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Weird Measurements (Medium)
Medium5
Array, Two pointers+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Large Weird Measurements
Medium5
Array, Two pointers+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Broadcast Tower
Medium5
Stack, Array
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Caki
Medium5
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cubes
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Spreadsheet Calculator
Medium5
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Reading List
Medium5
Array, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
HNL
Medium5
Brute force, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Credit Card Recovery
Medium5
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Watermelon bags
Medium5
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hacker
Medium5
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ćevapi
Medium5
Simulation, Sorting+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Snake
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
4s
Memory limit
64 MB
Judgeable
Calendar Fragment
Medium5
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Moocast
Medium5
Graph, Union-find+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cities and States
Medium5
Hash map, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Block Game
Medium5
Brute force, Bit manipulation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Base Stations
Medium5
Geometry, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Banknotes and Roulette
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Graph Search 2
Medium5
BFS, Graph
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Smallest sum no subsequence can make
Medium5
Backtracking, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Emoticons
Medium5
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
DNA string
Medium5
String, String matching+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Ruthless Boss
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Score of a Subsequence
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Segments greater than K
Medium5
Two pointers, Prefix sum
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jump Jump 2
Medium5
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Company Culture 2
Medium5
Tree, DFS+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Arithmetic and Geometric Sequences
Medium5
Math, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Connecting Edges 2
Medium5
Graph, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Company Culture 3
Medium5
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Vote (Large)
Medium5
Combinatorics, Probability+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Sitting (Large)
Medium5
Greedy, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Codejamon Cipher (Small)
Medium5
Dynamic programming, Hash map+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Sherlock and Parentheses (Small)
Medium5
Greedy, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Watson and Intervals (Small)
Medium5
Intervals, Sorting+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Rain (Small)
Medium5
Graph, BFS+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Jane's Flower Shop (Large)
Medium5
Binary search, Math
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Slides! (Small)
Medium5
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Phone Number Riddle (Small)
Medium5
String, Hash map+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Phone Number Riddle (Large)
Medium5
String, Hash map+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
The Last Word (Small)
Medium5
Greedy, String+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
BFFs (Small)
Medium5
Graph, Brute force+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Paper Pieces
Medium5
Brute force, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Four Operations
Medium5
BFS, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Convenience Store 2
Medium5
Math, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sprinklers
Medium5
Sorting, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Pareto
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Finding Prefixes
Medium5
Trie, String
No attempts yet
Time limit
1s
Memory limit
1536 MB
Judgeable
Sequence and Queries 15
Medium5
Segment tree, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Integer Sequence
Medium5
Math, Dynamic programming+2
No attempts yet
Time limit
0.25s
Memory limit
512 MB
Judgeable
Cow Dance Show
Medium5
Binary search, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Why Did the Cow Cross the Road 6
Medium5
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bulbs
Medium5
Greedy, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Flight Plan
Medium5
Geometry, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Junoh Lives for Lunch!!
Medium5
Binary search, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
What Is Dynamic Programming?
Medium5
Dynamic programming, Matrix+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tetromino
Medium5
Brute force, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Youngest BossGiven a directed acyclic chain of command, process swaps of two employees and report the age of the youngest superior of a queried employee, or * if none exists.	Medium5	GraphDFS+1	No attempts yet	1s	512 MB	Judgeable
Short Story ContestGiven words, a max line width C, and max lines per page L, find the fewest pages when each line is packed greedily left to right.	Medium5	GreedyString+1	No attempts yet	2s	512 MB	Judgeable
FocusGiven N closed intervals, find the minimum number of points needed so that every interval contains at least one chosen point.	Medium5	GreedyIntervals+2	No attempts yet	2s	512 MB	Judgeable
Laser SculptingGiven a block's height profile, count the number of horizontal 1 mm laser sweeps needed to carve it into the target shape.	Medium5	SimulationImplementation+1	No attempts yet	2s	512 MB	Judgeable
Erasing and WinningGiven an N-digit number and D, erase exactly D digits so the remaining digits, in order, form the largest possible number. Multiple test cases until 0 0.	Medium5	GreedyStack+2	No attempts yet	2s	512 MB	Judgeable
Winner of the Bubble GameTwo players alternately swap adjacent out-of-order pairs until the permutation is sorted; the one who cannot move loses. Decide the winner.	Medium5	CombinatoricsGame theory+1	No attempts yet	2s	512 MB	Judgeable
VampiresGiven two life totals, a hit threshold and a fixed damage, find the probability that vampire 1 wins a turn-based drain fight.	Medium5	ProbabilityDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
University CourseSimulate course selection each semester: from courses whose prerequisites are done, take up to M with highest priority, and report the schedule.	Medium5	Topological sortGreedy+2	No attempts yet	2s	512 MB	Judgeable
Sentence ReductionGiven tasks with weekday, start and end times, and point values, pick a non-overlapping set that maximizes total points, and report the per-day breakdown.	Medium5	Dynamic programmingSorting+2	No attempts yet	2s	512 MB	Judgeable
Strange BarGiven N kettle volumes and K people, find the largest integer amount X such that the sum over all kettles of floor(volume / X) is at least K.	Medium5	Binary searchArray+2	No attempts yet	1s	512 MB	Judgeable
Sum Decomposition 2Count ordered K-tuples of integers between 0 and N whose sum is N, modulo 1,000,000,000.	Medium5	Dynamic programmingCombinatorics+1	No attempts yet	1s	512 MB	Judgeable
Good Positions in a PermutationCount permutations of 1..N whose number of positions i with \|P_i - i\| = 1 equals a given K, modulo 1e9+7.	Medium5	CombinatoricsDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
Making the Array PalindromicMerge adjacent elements (each merge sums them) so the resulting array reads the same forwards and backwards, using the fewest merges. All values are positive.	Medium5	Two pointersGreedy+2	No attempts yet	1s	64 MB	Judgeable
Postal DeliveryGiven delivery counts at coordinates on a line and a truck capacity K, find the minimum total distance to deliver all letters and return to the origin.	Medium5	GreedySorting+1	No attempts yet	2s	512 MB	Judgeable
Alphabet StringInsert the fewest lowercase letters into s so that deleting some letters leaves exactly a through z in order.	Medium5	Dynamic programmingString+2	No attempts yet	2s	512 MB	Judgeable
Minimum number of islandsGiven a grid of land, water, and cloud cells, find the minimum possible number of 4-connected land islands if every cloud can be either land or water.	Medium5	GraphDFS+2	No attempts yet	2s	512 MB	Judgeable
Project PanoptesGiven n brightness readings and a lower bound p, find the smallest k >= p such that some arithmetic progression with step k lands only on dim days, where dim means below 0.8 times the average; output -1 if none exists.	Medium5	ArrayBrute force+2	No attempts yet	2s	512 MB	Judgeable
Make One SquareGiven three rectangles that can each be rotated 90 degrees, decide whether they can tile one square exactly with no overlaps or gaps.	Medium5	GeometryImplementation+2	No attempts yet	2s	512 MB	Judgeable
Chinese ClassicsGiven letters with returning marks (Re marks and numbered jump marks), simulate the reading rules and print the order in which letters are read.	Medium5	SimulationImplementation+1	No attempts yet	8s	512 MB	Judgeable
Two-Wheel BuggySimulate a two-wheeled buggy through N timed wheel-speed instructions and print the final axle position to five decimals.	Medium5	GeometrySimulation+1	No attempts yet	8s	512 MB	Judgeable
For the PeaceDecide whether n countries can each discard their missiles oldest-first so the gap between the largest and smallest remaining war potential never exceeds d.	Medium5	GreedyImplementation	No attempts yet	8s	512 MB	Judgeable
Champernowne ConstantFor each query, print the K digits of the Champernowne constant starting at decimal position N, where integers are concatenated in order.	Medium5	MathString matching+1	No attempts yet	8s	512 MB	Judgeable
Space Coconut Crab IIFor each T, count the triangles whose three sides are prime numbers summing to T, counting only congruence classes.	Medium5	MathNumber theory	No attempts yet	8s	512 MB	Judgeable
Autocorrelation FunctionA piecewise linear function is given by its endpoints; compute the integral of f(x)f(x+r) over the whole line for a given shift r.	Medium5	MathGeometry+2	No attempts yet	8s	512 MB	Judgeable
Gather on the ClockCards sit on a ring; repeatedly stack a card onto its clockwise neighbor for the value difference, and maximize the total score when one card remains.	Medium5	Dynamic programmingIntervals	No attempts yet	8s	512 MB	Judgeable
LettersGiven index i, return the uppercase letter at position i in the concatenation of all uppercase strings ordered by length then lexicographically.	Medium5	CombinatoricsMath	No attempts yet	0.2s	256 MB	Judgeable
Cutting into three piecesDecide whether the second string can be cut into three non-empty pieces and reordered to equal the first string, printing the shortest-first valid split.	Medium5	StringBrute force+1	No attempts yet	0.2s	256 MB	Judgeable
m-ary PartitionsCount the partitions of n into powers of m, for up to 1000 queries with n up to 10000.	Medium5	Dynamic programmingMath+2	No attempts yet	2s	512 MB	Judgeable
A Rational Sequence 3Find the rational number at position N in the breadth-first level-order traversal of the Calkin-Wilf-style binary tree rooted at 1/1, where left and right children are p/(p+q) and (p+q)/q.	Medium5	TreeMath+2	No attempts yet	2s	512 MB	Judgeable
Smoothed GardensGiven a triangle and a rope loop longer than its perimeter, find the area traced by a stake held tight in the loop.	Medium5	GeometryMath	No attempts yet	2s	512 MB	Judgeable
RobotGiven a grid with obstacles, a start cell, and a fixed cycling order of the four directions, simulate the robot that moves straight until blocked and report where it stops.	Medium5	SimulationImplementation+2	No attempts yet	1s	256 MB	Judgeable
Opening Day 2Given wok sizes, each cooking uses one or two distinct woks and produces the sum of their sizes; find the minimum number of cookings summing to exactly N.	Medium5	Dynamic programmingGreedy+2	No attempts yet	1s	256 MB	Judgeable
AssignmentsGiven deadlines and scores for N assignments, pick a subset schedulable within their deadlines to maximize total score.	Medium5	GreedySorting+2	No attempts yet	1s	256 MB	Judgeable
TaxFind the shortest path from S to D in a weighted undirected graph, then report it again after each tax rise adds p to every edge.	Medium5	Shortest pathGraph+2	No attempts yet	2s	256 MB	Judgeable
PasswordCount n-digit strings over 0-9 that contain every one of the m given digits at least once.	Medium5	CombinatoricsMath	No attempts yet	1s	64 MB	Judgeable
Grand OpeningGiven N bowls to produce and a multiset of wok sizes, each round uses one wok or two distinct woks of equal size, and you must reach exactly N bowls with the fewest rounds.	Medium5	Dynamic programmingGreedy+2	No attempts yet	1s	256 MB	Judgeable
It's Raining, ManGiven a set of distinct cards, decide whether they can be ordered in a row so that each neighbouring pair shares a rank or a suit.	Medium5	GraphDFS	No attempts yet	2s	512 MB	Judgeable
Jupiter OrbiterGiven queues with capacities, sensor writes between downlink windows, and per-window downlink limits, decide whether every queue can be emptied.	Medium5	SimulationQueue+1	No attempts yet	2s	512 MB	Judgeable
Key KnockingGiven a binary string of length 3n, greedily pick operations in each 3-bit block to reach a weight of at least 2n within n moves.	Medium5	GreedyImplementation+1	No attempts yet	1s	512 MB	Judgeable
Within Arm's ReachGiven segment lengths of a planar robotic arm and a target point, find where the tip lands when bent as close to the target as possible.	Medium5	GeometryMath+1	No attempts yet	2s	512 MB	Judgeable
Binomial coefficient queriesGiven M pairs N and K, print the binomial coefficient C(N, K) modulo 1,000,000,007.	Medium5	CombinatoricsMath+1	No attempts yet	1s	512 MB	Judgeable
AbbreviationScan a text and replace each maximal run of two or more single-capitalized words separated by single spaces with their initials followed by the original run in parentheses.	Medium5	StringSimulation+2	No attempts yet	1s	512 MB	Judgeable
Weird Measurements (Medium)Count the contiguous subarrays whose consecutive differences alternate in sign, with no zero differences allowed.	Medium5	ArrayTwo pointers+2	No attempts yet	2s	512 MB	Judgeable
Large Weird MeasurementsCount all contiguous intervals whose consecutive differences strictly alternate in sign, with any length-1 interval counting as weird.	Medium5	ArrayTwo pointers+2	No attempts yet	2s	512 MB	Judgeable
Broadcast TowerPlace a tower of height H in a row of buildings; a building west of it receives its signal if no taller building blocks the path. Maximize receivers.	Medium5	StackArray	No attempts yet	2s	512 MB	Judgeable
CakiGiven a list of overtake events, track car positions on a loop to find the final top six finishers.	Medium5	SimulationImplementation	No attempts yet	1s	512 MB	Judgeable
CubesDraw a 3D ASCII picture of an m by n grid of cube towers, painting cubes back to front and bottom to top so nearer cubes cover farther ones, then trim to the smallest bounding rectangle.	Medium5	SimulationImplementation+1	No attempts yet	1s	512 MB	Judgeable
Spreadsheet CalculatorCompute the value of every cell in a spreadsheet where cells hold either a non-negative number or a sum formula referring to other cell addresses, with no circular references.	Medium5	GraphDFS+1	No attempts yet	1s	512 MB	Judgeable
Reading ListTotal lifted books over a sequence of assignments, where each assigned book moves to the top of the tower.	Medium5	ArraySorting+2	No attempts yet	1s	128 MB	Judgeable
HNLGiven N clubs with points and one final round of matches, list every club that can still finish first under some set of results.	Medium5	Brute forceSorting+1	No attempts yet	1s	128 MB	Judgeable
Credit Card RecoveryGiven a 16-digit encrypted string, find all original card numbers that the given encrypt rule (bump min up, max down, swap) would produce, printed in ascending order or banana.	Medium5	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
Watermelon bagsGiven counts of 1 kg to 5 kg watermelons, find the minimum number of 5 kg capacity bags needed to carry them all.	Medium5	GreedyMath+1	No attempts yet	1s	128 MB	Judgeable
HackerBuild the minimal list of URLs that covers every known parameter with every malicious value, packing pairs into queries of at most P parameters by the given grouping rule.	Medium5	ImplementationString+2	No attempts yet	1s	128 MB	Judgeable
ĆevapiEach day a new raft joins; simulate Goran's run across both banks under L meters and report meters on each bank and the portions eaten.	Medium5	SimulationSorting+1	No attempts yet	3s	128 MB	Judgeable
SnakeSimulate snakes that move forward, or turn right then left, given a board with obstacles for T seconds.	Medium5	SimulationImplementation+1	No attempts yet	4s	64 MB	Judgeable
Calendar FragmentFind all years from 1900 to 2100 whose generated 28 by 73 calendar contains the given small character fragment at some aligned position.	Medium5	ImplementationSimulation+1	No attempts yet	1s	64 MB	Judgeable
MoocastGiven N cow coordinates, find the smallest integer X such that the graph connecting pairs whose squared distance is at most X is connected.	Medium5	GraphUnion-find+2	No attempts yet	2s	512 MB	Judgeable
Cities and StatesGiven up to 200,000 cities with names and two-letter state codes, count unordered pairs whose first two name letters match the other city's state code and vice versa, with different states.	Medium5	Hash mapString+2	No attempts yet	2s	512 MB	Judgeable
Block GameFor each letter, find the minimum number of blocks needed so any choice of one word per board can be spelled at once.	Medium5	Brute forceBit manipulation	No attempts yet	2s	512 MB	Judgeable
Base StationsAmong points with different frequency labels, find the farthest pair and print the squared distance.	Medium5	GeometryBrute force+1	No attempts yet	2s	512 MB	Judgeable
Banknotes and RouletteSplit banknotes so the two equal-sum groups leave the smallest leftover, then add half of twice that leftover to each person's total.	Medium5	Dynamic programmingArray+2	No attempts yet	2s	512 MB	Judgeable
Graph Search 2After each of q planned roads is built, print each city's shortest-path distance to city 1, where it takes one edge.	Medium5	BFSGraph	No attempts yet	2s	512 MB	Judgeable
Smallest sum no subsequence can makeGiven N ≤ 20 numbers, find the smallest natural number that is not the sum of any non-empty subsequence.	Medium5	BacktrackingBrute force+1	No attempts yet	2s	512 MB	Judgeable
EmoticonsStarting from one emoticon on screen with an empty clipboard, find the minimum seconds to reach exactly S using copy, paste, and delete-one operations.	Medium5	BFSGraph+2	No attempts yet	2s	512 MB	Judgeable
DNA stringGiven a DNA string S, find the shortest string over A, C, G, T that never occurs as a contiguous substring of S, breaking ties lexicographically.	Medium5	StringString matching+1	No attempts yet	2s	512 MB	Judgeable
The Ruthless BossGiven n distinct deadlines, find the largest integer k so that scheduling all jobs, each taking exactly k hours back to back, meets every deadline.	Medium5	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Score of a SubsequenceFind the maximum over all contiguous subarrays of the weighted sum where the k-th element from the subarray start contributes k times its value.	Medium5	Dynamic programmingArray+2	No attempts yet	2s	512 MB	Judgeable
Segments greater than KCount the contiguous subarrays whose sum exceeds k.	Medium5	Two pointersPrefix sum	No attempts yet	2s	512 MB	Judgeable
Jump Jump 2Given a walk that adds or subtracts A_i at each step, count the stones reachable from start s, excluding s unless a cycle returns to it.	Medium5	GraphBFS+2	No attempts yet	2s	512 MB	Judgeable
Company Culture 2Given a tree of boss relations, apply subtree-wide praise additions in real time and answer point total queries.	Medium5	TreeDFS+2	No attempts yet	5s	512 MB	Judgeable
Arithmetic and Geometric SequencesCount integers from 1 to u that lie in an arithmetic sequence or a geometric sequence, counting overlaps only once.	Medium5	MathHash map+2	No attempts yet	2s	512 MB	Judgeable
Connecting Edges 2Given a weighted edge list, pick the order of adding edges that makes the total weight added up to the moment s and t first become connected as small as possible.	Medium5	GraphSorting+2	No attempts yet	2s	512 MB	Judgeable
Company Culture 3Employees sit in a rooted tree. A praise of w given to employee i from a subordinate adds w to i and every ancestor up to the president; type 2 queries ask an employee's running total.	Medium5	TreeDFS+2	No attempts yet	2s	512 MB	Judgeable
Vote (Large)Given N supporters of A and M of B in random arrival order, find the probability A leads after every vote; a ballot-problem computation.	Medium5	CombinatoricsProbability+2	No attempts yet	5s	512 MB	Judgeable
Sitting (Large)Find the maximum number of players seatable in an R by C grid so no player has occupied seats on both sides horizontally or vertically.	Medium5	GreedyMath+2	No attempts yet	5s	512 MB	Judgeable
Codejamon Cipher (Small)For each enciphered string, count the sentences of vocabulary words whose letter multisets concatenate to it, modulo 1e9+7.	Medium5	Dynamic programmingHash map+1	No attempts yet	5s	512 MB	Judgeable
Sherlock and Parentheses (Small)Given L left and R right parentheses, arrange all of them to maximize the count of balanced non-empty substrings, counted by position.	Medium5	GreedyMath+2	No attempts yet	5s	512 MB	Judgeable
Watson and Intervals (Small)Generate N intervals from a recurrence, then remove exactly one interval so the number of integers covered by the rest is minimized.	Medium5	IntervalsSorting+1	No attempts yet	5s	512 MB	Judgeable
Rain (Small)Given a small grid of island heights, compute the total water trapped after rain, where water escapes to sea at height 0.	Medium5	GraphBFS+2	No attempts yet	5s	512 MB	Judgeable
Jane's Flower Shop (Large)Find the internal rate of return for a cash flow series by solving the polynomial equation that zeroes the net present value.	Medium5	Binary searchMath	No attempts yet	5s	512 MB	Judgeable
Slides! (Small)Given B up to 6 and M up to 20, decide if exactly M paths from building 1 to B exist, and print the fixed-rule matrix when possible.	Medium5	CombinatoricsDynamic programming+1	No attempts yet	5s	512 MB	Judgeable
Phone Number Riddle (Small)Given a shuffled string formed from the English words of a phone number's digits, recover the digits, which are guaranteed to be in ascending order.	Medium5	StringHash map+2	No attempts yet	5s	512 MB	Judgeable
Phone Number Riddle (Large)A shuffled concatenation of the English words for a phone number's digits is given; recover the digits, which are in ascending order.	Medium5	StringHash map+2	No attempts yet	5s	512 MB	Judgeable
The Last Word (Small)Given a string S, insert each letter at the front or back of the word as it arrives, and find the alphabetically largest word obtainable.	Medium5	GreedyString+2	No attempts yet	5s	512 MB	Judgeable
BFFs (Small)Find the largest subset of kids that can be arranged in a circle so each kid sits next to their BFF.	Medium5	GraphBrute force+1	No attempts yet	5s	512 MB	Judgeable
Paper PiecesCut an N x M digit grid into horizontal or vertical strips and maximize the sum of the numbers those strips form.	Medium5	Brute forceBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Four OperationsStarting from s, apply +, -, , / (each replacing s with s+s, s-s, ss, or s/s) to reach t in the fewest steps, ties broken lexicographically.	Medium5	BFSMath+1	No attempts yet	2s	512 MB	Judgeable
Convenience Store 2Given n customer points, place one store anywhere to minimize the total Manhattan distance to all customers and print that minimum sum.	Medium5	MathSorting+2	No attempts yet	2s	512 MB	Judgeable
SprinklersPlace two fixed sprinklers and choose radii so every flower is covered, minimizing the sum of squared radii; print that minimum as an integer.	Medium5	SortingGreedy+2	No attempts yet	2s	512 MB	Judgeable
ParetoChoose k accounts maximizing B minus A, where A = 100k/N and B is their share of all money as a percent.	Medium5	GreedySorting+2	No attempts yet	1s	64 MB	Judgeable
Finding PrefixesGiven a set of N strings, count how many of M query strings appear as a prefix of at least one string in the set.	Medium5	TrieString	No attempts yet	1s	1536 MB	Judgeable
Sequence and Queries 15Maintain an array under point updates and, after each change, report the smallest index holding the minimum value.	Medium5	Segment treeImplementation	No attempts yet	1s	512 MB	Judgeable
Integer SequenceGiven x, y, the last two digits of A0 and A1, and a large index n, print the last two digits of An where An = xAn-1 + yAn-2.	Medium5	MathDynamic programming+2	No attempts yet	0.25s	512 MB	Judgeable
Cow Dance ShowFind the smallest stage size K so that the total show time, where the next cow starts as soon as a dancer leaves, stays within T_max.	Medium5	Binary searchSimulation+2	No attempts yet	2s	512 MB	Judgeable
Why Did the Cow Cross the Road 6Given an N x N grid of pastures, some adjacent pairs blocked by roads, and K cows on distinct cells, count the pairs of cows that cannot reach each other without crossing a road.	Medium5	GraphBFS+2	No attempts yet	2s	512 MB	Judgeable
BulbsFind the fewest laser shots needed so every bulb is on, where each shot also toggles bulbs below it and to its left.	Medium5	GreedyImplementation	No attempts yet	2s	512 MB	Judgeable
Flight PlanFor each pair of latitude/longitude points on a sphere, compute the great-circle distance and the distance of the two-leg path that keeps latitude then longitude constant.	Medium5	GeometryMath+2	No attempts yet	2s	512 MB	Judgeable
Junoh Lives for Lunch!!Given each friend's starting position and running speed, decide whether all N friends can meet at one point within time T.	Medium5	Binary searchSorting+2	No attempts yet	2s	512 MB	Judgeable
What Is Dynamic Programming?Count paths from the top-left cell to the bottom-right cell of an n by m grid when each step moves right, down, or diagonally down-right, printed modulo 1e9+7.	Medium5	Dynamic programmingMatrix+1	No attempts yet	2s	512 MB	Judgeable
TetrominoGiven an N x M grid of positive integers, place one of the 5 tetrominoes (with rotations and reflections) to maximize the sum of covered cells.	Medium5	Brute forceImplementation+2	No attempts yet	2s	512 MB	Judgeable