Problems

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Total results29,077 problems

Mailing Origami
Medium7
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Power Tiller
Medium7
Bit manipulation, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Biggest Slice
Medium7
Number theory, Math+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Maze movement
Medium7
Graph, Number theory
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Can't stop playing
Medium7
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
10s
Memory limit
256 MB
Judgeable
Vocabulary
Medium7
Dynamic programming, String+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Alien Invaders
Medium7
Dynamic programming, Divide and conquer+2
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Biking Duck
Medium7
Shortest path, Geometry+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Gathering
Medium7
Geometry, Sorting+2
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Why-Salesman Tour
Medium7
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
9s
Memory limit
256 MB
Judgeable
Golf Bot
Medium7
Divide and conquer, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Rock Festival
Medium7
Union-find, Geometry+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Playing with Geometry
Medium7
Geometry, String matching+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Safe Secret
Medium7
Dynamic programming, Intervals
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Big Picture
Medium7
String matching
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Table Tennis Team Lineup
Medium7
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Third Round Standings
Medium7
Prefix sum, Greedy
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
Stack Copying Game
Medium7
Tree, Stack
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Recursive Function z
Medium7
Math, Graph+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Knights
Medium7
Dynamic programming, Matrix+1
No attempts yet
Time limit
60s
Memory limit
256 MB
Judgeable
Antennas
Medium7
Dynamic programming, Sorting+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Toll
Medium7
Shortest path, Geometry+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Robot Race
Medium7
Geometry, Brute force
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Bus
Medium7
Graph, Binary search
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Preparation Lectures
Medium7
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
32 MB
Judgeable
Apartment floor plan
Medium7
Dynamic programming, Divide and conquer+1
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Cube Coloring
Medium7
Combinatorics, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Decoding Ancient Messages
Medium7
Graph, Greedy
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
LR
Medium7
Dynamic programming, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Proportional Representation
Medium7
Binary search, Math
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Unfair Game
Medium7
Game theory, Math
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Guillotine Card Game
Medium7
Game theory, Backtracking+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Quarantine Station Placement
Medium7
Backtracking, Graph
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Minimum spanning tree after deleting one edge
Medium7
Minimum spanning tree, Tree+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Rings
Medium7
Geometry, Math
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Snake Game
Medium7
Dynamic programming, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
Barbarian Tablets
Medium7
String matching, Trie
No attempts yet
Time limit
4s
Memory limit
768 MB
Judgeable
Frisbee
Medium7
Dynamic programming, Sorting
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Marathon sub-routes
Medium7
Segment tree, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Cow Jog
Medium7
Dynamic programming, Binary search+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Minimum Median Spanning Tree
Medium7
Minimum spanning tree, Union-find+1
No attempts yet
Time limit
8s
Memory limit
256 MB
Judgeable
Billiard
Medium7
Geometry, Simulation
No attempts yet
Time limit
8s
Memory limit
256 MB
Judgeable
Ancient Commemorative Monolith
Medium7
Matrix, Recursion+2
No attempts yet
Time limit
8s
Memory limit
256 MB
Judgeable
Moovie Mooving
Medium7
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Grass Cownoisseur
Medium7
Graph, Topological sort+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
SIRO Challenge
Medium7
Dynamic programming, Shortest path+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Venn Diagram
Medium7
Geometry, Binary search+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
NEO
Medium7
Matrix, Stack+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
WTF Transformation
Medium7
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Dividing the Treasures
Medium7
Divide and conquer, Brute force+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Cutting the Cake 2
Medium7
Game theory, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Coding Contest
Medium7
Binary search, Simulation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Fortress Wall
Medium7
Prefix sum, Matrix
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Revenge of the ants 1
Medium7
Math, Number theory+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Slave to achievements 1
Medium7
Dynamic programming, Probability+2
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Rotating the Keyring
Medium7
Array, Math+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Jan's coloring book
Medium7
Graph, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Library shelf tidying
Medium7
Dynamic programming, Binary search
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Cow Hopscotch
Medium7
Dynamic programming, Prefix sum
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Censoring
Medium7
String matching, Stack+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Coin type identification
Medium7
Union-find, Topological sort+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Computer Lab
Medium7
Heap, Divide and conquer+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Palindrome Path 3
Medium7
Dynamic programming, Matrix
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Trapped in the Haybales
Medium7
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Trapped in the Haybales
Medium7
Two pointers, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Palindromic Paths
Medium7
DFS, Hash map+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Bowling
Medium7
Dynamic programming, Simulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Tug of War
Medium7
Graph, Dynamic programming
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Catering
Medium7
Graph, Shortest path+1
No attempts yet
Time limit
4s
Memory limit
256 MB
Judgeable
Virtual Keyboard Typing
Medium7
Dynamic programming, Shortest path+1
No attempts yet
Time limit
4s
Memory limit
256 MB
Judgeable
369 Game Count
Medium7
Dynamic programming, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Cutting an L-shaped paper
Medium7
Dynamic programming, Geometry+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Queen Bee
Medium7
Dynamic programming, Prefix sum
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Mat
Medium7
Dynamic programming, Intervals+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Palembang Bridges
Medium7
Sorting, Greedy+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
A Journey to Greece
Medium7
Dynamic programming, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bounty Hunter II
Medium7
Graph
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Divisions
Medium7
Number theory
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Souvenirs
Medium7
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Ruka
Medium7
Segment tree, Prefix sum
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Restaurant Locations from Delivery Times
Medium7
Geometry, Intervals+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
How many binary sequences
Medium7
Brute force, Bit manipulation
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Array splitting
Medium7
Divide and conquer, Recursion+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The festival must go on
Medium7
Binary search, Tree+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Block Stacking
Medium7
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
City Influence
Medium7
Segment tree, Sorting+1
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Following Flow
Medium7
Probability, Matrix+1
No attempts yet
Time limit
1s
Memory limit
8 MB
Judgeable
Jogging
Medium7
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
16 MB
Judgeable
Lonely mdic
Medium7
Geometry, Sorting+1
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Covering the grid
Medium7
Dynamic programming, Prefix sum
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Wiring
Medium7
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Gift Boxes
Medium7
Dynamic programming, Greedy
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Cutting the Tofu Board
Medium7
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Tetris 2
Medium7
Dynamic programming, Matrix
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Calvinball championship
Medium7
Combinatorics, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Calvinball championship, again
Medium7
Backtracking, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
School Canteen
Medium7
Dynamic programming, Matrix+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Calvinball team split
Medium7
Graph, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Calvinball team assignment
Medium7
Graph, Backtracking+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Calvinball team assignment
Medium7
Backtracking, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Mailing OrigamiFind the area of the smallest rotated rectangle enclosing N given points, rounded to the nearest integer.	Medium7	GeometrySorting+1	No attempts yet	1s	256 MB	Judgeable
Power TillerCount distinct positions reachable by steps of lengths 1, 2, 4 and so on moving only right or up inside an A by B rectangle.	Medium7	Bit manipulationDynamic programming+1	No attempts yet	3s	256 MB	Judgeable
Biggest SliceCompute the largest slice area from n radial cuts where each cut rotates by a fixed angle around the circle center.	Medium7	Number theoryMath+1	No attempts yet	2s	256 MB	Judgeable
Maze movementFind the max people per minute from the lowest to the highest room where pairs sharing a divisor above 1 are linked with capacity equal to their gcd.	Medium7	GraphNumber theory	No attempts yet	2s	256 MB	Judgeable
Can't stop playingStick each arriving power-of-two block to the left or right end, merge equal neighbours, and report if one block can remain with the smallest direction string.	Medium7	Dynamic programmingBit manipulation+2	No attempts yet	10s	256 MB	Judgeable
VocabularyCount ways to replace every question mark with a lowercase letter so the three words are distinct and in lexicographic order.	Medium7	Dynamic programmingString+1	No attempts yet	5s	256 MB	Judgeable
Alien InvadersDestroy each alien within its time window using bombs, where a bomb of power R kills all aliens present within distance R at cost R, for minimum total fuel.	Medium7	Dynamic programmingDivide and conquer+2	No attempts yet	3s	256 MB	Judgeable
Biking DuckFind the shortest travel time between two map points, walking anywhere but biking only between stations, with free station placement off the map.	Medium7	Shortest pathGeometry+1	No attempts yet	2s	256 MB	Judgeable
GatheringPick an integer intersection within Manhattan distance d of every house so the sum of Manhattan travel distances is smallest, or report impossible.	Medium7	GeometrySorting+2	No attempts yet	3s	256 MB	Judgeable
Why-Salesman TourDecide whether a metric graph with up to 14 vertices has a Hamiltonian cycle of total length exactly L.	Medium7	Dynamic programmingBit manipulation+1	No attempts yet	9s	256 MB	Judgeable
Golf BotCount how many hole distances equal one dial distance or the sum of two dial distances.	Medium7	Divide and conquerMath+1	No attempts yet	1s	256 MB	Judgeable
Rock FestivalAdd up the areas of rectangles that touch by edge or corner and print the largest connected patch.	Medium7	Union-findGeometry+1	No attempts yet	1s	256 MB	Judgeable
Playing with GeometryDecide whether two rectilinear polygons reduce to the same permutomino after deleting empty grid lines and rotating by multiples of 90 degrees.	Medium7	GeometryString matching+1	No attempts yet	1s	256 MB	Judgeable
The Safe SecretFor each ring rotation, replace each ? with +, - or * and parenthesize to get the min and max values, then join their digits in order.	Medium7	Dynamic programmingIntervals	No attempts yet	1s	256 MB	Judgeable
The Big PictureCount the top-left positions where the given black-and-white painting matches the masterpiece exactly without rotation.	Medium7	String matching	No attempts yet	2s	512 MB	Judgeable
Table Tennis Team LineupReorder the queue with the fewest take-and-reinsert moves so each consecutive block of K holds the next K weakest players.	Medium7	Dynamic programmingSorting+1	No attempts yet	1s	64 MB	Judgeable
Third Round StandingsGiven two rounds of scores from 0 to 650, the task asks each contestant's highest and lowest final rank over third-round scores that respect dominance.	Medium7	Prefix sumGreedy	No attempts yet	1s	32 MB	Judgeable
Stack Copying GameMaintain up to 300,000 persistent stack versions built by push, pop, or copy, and answer popped values and common-element counts for pairs of versions.	Medium7	TreeStack	No attempts yet	1s	64 MB	Judgeable
Recursive Function zYou evaluate the recursive function at n/m by tracing its arguments into a repeating cycle and solving the linear equations exactly.	Medium7	MathGraph+1	No attempts yet	5s	256 MB	Judgeable
KnightsCount non-attacking knight placements on an M by N board with M up to 4 and N up to 1e9, modulo 1000000009.	Medium7	Dynamic programmingMatrix+1	No attempts yet	60s	256 MB	Judgeable
AntennasPlace carrier-specific or shared antennas on a line so each house interval meets a matching coverage interval at minimum cost.	Medium7	Dynamic programmingSorting+1	No attempts yet	2s	256 MB	Judgeable
TollWalk a rectilinear route while buying the fewest unit tickets, where each square territory covers travel inside it.	Medium7	Shortest pathGeometry+1	No attempts yet	2s	256 MB	Judgeable
Robot RaceFor each polygonal path, decide whether the straight-line distance to any later point never increases along the walk.	Medium7	GeometryBrute force	No attempts yet	2s	256 MB	Judgeable
BusPick one rider each day to pay the full rent so the largest overpayment above each rider's fair share is as small as possible.	Medium7	GraphBinary search	No attempts yet	2s	256 MB	Judgeable
Preparation LecturesBoth lecturers teach each of N teams for t_i time and the goal is the shortest overlap-free schedule for all lectures.	Medium7	GreedySorting+1	No attempts yet	2s	32 MB	Judgeable
Apartment floor planCover an N by M floor with integer-sided rectangles that each touch the outer edge so the sum of squared area deviations from K is minimal.	Medium7	Dynamic programmingDivide and conquer+1	No attempts yet	2s	64 MB	Judgeable
Cube ColoringCount the cubes in an X by Y by Z box by Manhattan distance from a given cube modulo N.	Medium7	CombinatoricsPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
Decoding Ancient MessagesChoose one cell in each row and column so the chosen letters, sorted ascending, are lexicographically smallest.	Medium7	GraphGreedy	No attempts yet	2s	128 MB	Judgeable
LRFill each ? with an allowed character to form a valid L and R expression with the largest possible value, or report invalid.	Medium7	Dynamic programmingString+1	No attempts yet	2s	128 MB	Judgeable
Proportional RepresentationGiven total votes and seats each party won under the D'Hondt rule, find the smallest and largest vote count each party could have received.	Medium7	Binary searchMath	No attempts yet	5s	128 MB	Judgeable
Unfair GameHanako and Jiro alternately remove 1 to A and 1 to B stones from one of N heaps, and the player who takes the last stone wins.	Medium7	Game theoryMath	No attempts yet	2s	128 MB	Judgeable
Guillotine Card GameCompute each player's final score in a three-player card game where one player secretly plays to minimize another player's score.	Medium7	Game theoryBacktracking+1	No attempts yet	3s	128 MB	Judgeable
Quarantine Station PlacementPlace quarantine stations on the fewest islands so every liner touches a station, or report that K stations cannot cover all liners.	Medium7	BacktrackingGraph	No attempts yet	10s	512 MB	Judgeable
Minimum spanning tree after deleting one edgeFor each edge, report the MST weight of the graph with that edge removed, or -1 when it disconnects.	Medium7	Minimum spanning treeTree+1	No attempts yet	3s	256 MB	Judgeable
RingsDecide whether two unit circles in 3D space are linked like chain rings from their centers and orientation vectors.	Medium7	GeometryMath	No attempts yet	3s	128 MB	Judgeable
Snake GameGuide a snake that steps forward or climbs one row while reversing direction and eat every apple with the fewest button presses.	Medium7	Dynamic programmingShortest path+1	No attempts yet	1s	32 MB	Judgeable
Barbarian TabletsEach query asks how many words shown so far contain the tablet word of barbarian S as a contiguous substring.	Medium7	String matchingTrie	No attempts yet	4s	768 MB	Judgeable
FrisbeeChoose and order some of up to 20 cows so their total height reaches H while maximizing the worst remaining strength margin.	Medium7	Dynamic programmingSorting	No attempts yet	1s	256 MB	Judgeable
Marathon sub-routesGiven checkpoint coordinates with point updates, report the shortest Manhattan route over each queried interval with at most one interior checkpoint skipped.	Medium7	Segment treeMath	No attempts yet	1s	256 MB	Judgeable
Cow JogCows start in fixed order with fixed speeds, and you assign the fewest lanes so no two cows in one lane ever meet by time T.	Medium7	Dynamic programmingBinary search+1	No attempts yet	1s	256 MB	Judgeable
Minimum Median Spanning TreeFor each connected graph with an even node count, find the spanning tree whose median edge cost is smallest and report that median.	Medium7	Minimum spanning treeUnion-find+1	No attempts yet	8s	256 MB	Judgeable
BilliardPredict which stationary ball a struck billiard ball hits first as it reflects off cushions over a path of length 10000.	Medium7	GeometrySimulation	No attempts yet	8s	256 MB	Judgeable
Ancient Commemorative MonolithThe program parses each bitmap into nested boxes and glyphs and prints the bracketed transliteration with mirror reading resolved.	Medium7	MatrixRecursion+2	No attempts yet	8s	256 MB	Judgeable
Moovie MoovingChoose the fewest movies, each used at most once, whose showings chain together to cover every moment from time 0 to time L.	Medium7	Dynamic programmingBit manipulation+1	No attempts yet	1s	256 MB	Judgeable
Grass CownoisseurStarting from field 1 and returning to it, visit the most distinct fields while traveling at most one directed path backwards.	Medium7	GraphTopological sort+1	No attempts yet	1s	256 MB	Judgeable
SIRO ChallengeJiro starts at station s, visits as many of up to 16 ramen stations as possible, and returns within time t, paying rail travel plus eating time.	Medium7	Dynamic programmingShortest path+2	No attempts yet	8s	512 MB	Judgeable
Venn DiagramPlace two circles with given areas and overlap inside a rectangle, or report that the placement is impossible.	Medium7	GeometryBinary search+1	No attempts yet	8s	512 MB	Judgeable
NEOFind the largest submatrix with at least two rows and columns in which every submatrix meets the corner-sum inequality.	Medium7	MatrixStack+1	No attempts yet	1s	256 MB	Judgeable
WTF TransformationChoose the ID array that maximizes the two-phase rotating sum and output that maximum with the lexicographically smallest optimal ID array.	Medium7	Dynamic programmingPrefix sum+1	No attempts yet	1s	256 MB	Judgeable
Dividing the TreasuresGive each treasure to Anna, to Bruno, or to nobody so the two market totals differ by at most D and Bruno's preciousness minus Anna's is maximal.	Medium7	Divide and conquerBrute force+1	No attempts yet	10s	1024 MB	Judgeable
Cutting the Cake 2JOI chooses the first slice of a round cake, then both sides take exposed ends in turn against an opponent who always takes the larger end.	Medium7	Game theoryDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
Coding ContestPlace coders in the free starting slots so the queue contest that pairs the strongest and weakest of each front triple leaves the strongest possible survivor.	Medium7	Binary searchSimulation+1	No attempts yet	1s	256 MB	Judgeable
Fortress WallCount square one-cell-thick borders of size at least L that fit in an H by W grid without covering a tree.	Medium7	Prefix sumMatrix	No attempts yet	10s	512 MB	Judgeable
Revenge of the ants 1Ants march both ways around a circular rail and reverse on head-on meeting; find the first time every ant is back at its start with its initial direction.	Medium7	MathNumber theory+1	No attempts yet	5s	256 MB	Judgeable
Slave to achievements 1Craft as many N-cost daggers as possible and reclaim 0-to-K chips per dagger until fewer than N remain then print each final remainder probability modulo 1e9+7.	Medium7	Dynamic programmingProbability+2	No attempts yet	3s	256 MB	Judgeable
Rotating the KeyringCount all wrong key tries made while doors 1 to N are unlocked in cyclic order K times with a rotating keyring.	Medium7	ArrayMath+1	No attempts yet	1s	64 MB	Judgeable
Jan's coloring bookCount proper colorings of one of eight fixed maps using at most three of K colors with adjacent areas different.	Medium7	GraphCombinatorics+1	No attempts yet	1s	64 MB	Judgeable
Library shelf tidyingGiven current and target shelf layouts, find the minimum number of books to lift when sliding a book into an empty spot on the same shelf costs nothing.	Medium7	Dynamic programmingBinary search	No attempts yet	1s	64 MB	Judgeable
Cow HopscotchCount paths from the top-left to the bottom-right cell moving down and right where consecutive cells hold different values.	Medium7	Dynamic programmingPrefix sum	No attempts yet	1s	256 MB	Judgeable
CensoringRepeatedly delete the leftmost occurrence of any of N forbidden words from string S until none remains and print the result.	Medium7	String matchingStack+1	No attempts yet	1s	256 MB	Judgeable
Coin type identificationDetermine each coin fixed type from the pairwise weighing results, printing ? when it is not unique.	Medium7	Union-findTopological sort+2	No attempts yet	2s	512 MB	Judgeable
Computer LabNew students each take the middle seat of the longest empty stretch, and each query asks where a given arrival sits.	Medium7	HeapDivide and conquer+1	No attempts yet	4s	512 MB	Judgeable
Palindrome Path 3Count the paths from the top-left to the bottom-right corner moving only right or down whose letters form a palindrome, modulo 1000000007.	Medium7	Dynamic programmingMatrix	No attempts yet	1s	256 MB	Judgeable
Trapped in the HaybalesMeasure the total length of starting positions between sorted bales from which repeated run-up breaks can reach neither the leftmost nor the rightmost bale.	Medium7	Dynamic programmingSorting+2	No attempts yet	1s	256 MB	Judgeable
Trapped in the HaybalesBessie breaks any bale smaller than her running start, and you must find the cheapest single bale to enlarge so she never leaves the outer bales.	Medium7	Two pointersSorting+1	No attempts yet	1s	256 MB	Judgeable
Palindromic PathsCount distinct palindromic strings spelled by right-down paths from the top-left to the bottom-right of an N by N letter grid.	Medium7	DFSHash map+1	No attempts yet	1s	256 MB	Judgeable
BowlingCount the distinct bowling games whose frame symbols and running totals match the blurred notes.	Medium7	Dynamic programmingSimulation	No attempts yet	1s	256 MB	Judgeable
Tug of WarDecide if 2n contestants, each with one left spot, one right spot, and a strength, split into two disjoint teams of n whose strength sums differ by at most k.	Medium7	GraphDynamic programming	No attempts yet	3s	256 MB	Judgeable
CateringCover all n event locations with at most k routes starting from the depot so the total equipment moving cost is minimal.	Medium7	GraphShortest path+1	No attempts yet	4s	256 MB	Judgeable
Virtual Keyboard TypingFind the fewest arrow and select presses that type the given text on a sliding-cursor virtual keyboard, including the final Enter.	Medium7	Dynamic programmingShortest path+1	No attempts yet	4s	256 MB	Judgeable
369 Game CountCount numbers from A to B that are multiples of 3 or contain the digit 3, 6, or 9, and output the count modulo 20150523.	Medium7	Dynamic programmingString+1	No attempts yet	1s	256 MB	Judgeable
Cutting an L-shaped paperThe program cuts the given L-shaped sheet with guillotine cuts into integer-sided squares with the fewest pieces.	Medium7	Dynamic programmingGeometry+1	No attempts yet	2s	256 MB	Judgeable
Queen BeeSimulate N days of growth on an M by M grid where each inner cell copies the largest daily growth among its left, upper-left, and upper neighbors.	Medium7	Dynamic programmingPrefix sum	No attempts yet	2s	256 MB	Judgeable
MatChoose a set of top-anchored and bottom-anchored rectangles with disjoint interiors that maximizes total profit.	Medium7	Dynamic programmingIntervals+1	No attempts yet	1s	512 MB	Judgeable
Palembang BridgesChoose positions for up to two bridges so the total driving distance of all citizens is minimized.	Medium7	SortingGreedy+1	No attempts yet	2s	256 MB	Judgeable
A Journey to GreecePlan a round trip from Athens that visits every listed site within time G, using at most one fixed-time taxi jump.	Medium7	Dynamic programmingShortest path+1	No attempts yet	2s	1024 MB	Judgeable
Bounty Hunter IIFind the smallest number of vertex-disjoint directed paths that together visit every vertex of a given acyclic directed graph.	Medium7	Graph	No attempts yet	2s	256 MB	Judgeable
DivisionsCount the positive divisors of the given integer N, which is at most 10^18.	Medium7	Number theory	No attempts yet	1s	256 MB	Judgeable
SouvenirsBuy souvenirs from merchants in order with gold and silver coins and choose how to pay each price to maximize the number bought.	Medium7	Dynamic programmingGreedy+1	No attempts yet	1s	256 MB	Judgeable
RukaUpdate vectors of a polyline through cursor commands and report how many segments cross the coordinate axes.	Medium7	Segment treePrefix sum	No attempts yet	2s	512 MB	Judgeable
Restaurant Locations from Delivery TimesFor each friend, print the lexicographically smallest integer point at Manhattan distance exactly t that stays at distance at least t from every friend.	Medium7	GeometryIntervals+1	No attempts yet	2s	512 MB	Judgeable
How many binary sequencesFind the smallest set of length-K binary strings so each given 0-1-2 string with at most two ones is the sum of two members at Hamming distance at most two.	Medium7	Brute forceBit manipulation	No attempts yet	3s	256 MB	Judgeable
Array splittingRepeatedly quarter an N by M array until a side reaches 1, then list each distinct strip length with its count modulo 1234567891.	Medium7	Divide and conquerRecursion+2	No attempts yet	1s	256 MB	Judgeable
The festival must go onPick M roads of a weighted tree so the longest path using only picked roads is as short as possible.	Medium7	Binary searchTree+1	No attempts yet	1s	256 MB	Judgeable
Block StackingCount distinct front-view colorings of supported stacks of width W and height at most H built from unlimited blocks of widths 1 to K, modulo 1e9+7.	Medium7	Dynamic programmingCombinatorics+1	No attempts yet	1s	32 MB	Judgeable
City InfluenceAdd N weighted rectangles on a billion by billion grid and print the sum of squared cell values modulo 1,000,000,007.	Medium7	Segment treeSorting+1	No attempts yet	2s	64 MB	Judgeable
Following FlowCompute the expected travel time from vertex 0 to vertex N when each step follows a uniformly random outgoing edge with its own crossing time.	Medium7	ProbabilityMatrix+1	No attempts yet	1s	8 MB	Judgeable
JoggingFor each rest point given in increasing order, print the largest angle in radians to a star with greater x, or zero when no such star exists.	Medium7	GeometrySorting+1	No attempts yet	1s	16 MB	Judgeable
Lonely mdicGiven N circles, count the ones fully covered by the union of the rest.	Medium7	GeometrySorting+1	No attempts yet	2s	64 MB	Judgeable
Covering the gridPlace corner-touching rectangles chaining from the top-left cell to the bottom-right cell to maximize the sum of covered cell values.	Medium7	Dynamic programmingPrefix sum	No attempts yet	1s	256 MB	Judgeable
WiringCount how many distinct wires appear after N squared triangular steps join nails around a circle.	Medium7	Number theoryMath	No attempts yet	1s	256 MB	Judgeable
Gift BoxesStarting from sector 0 of a circular hall, a courier with capacity K must hand one gift to each of N teams and return, minimizing total walking time.	Medium7	Dynamic programmingGreedy	No attempts yet	3s	512 MB	Judgeable
Cutting the Tofu BoardPair up adjacent cells of a graded N by N board to maximize the sum of pair prices, leaving cells unpaired when that pays more.	Medium7	Dynamic programmingBit manipulation+1	No attempts yet	1s	256 MB	Judgeable
Tetris 2Count the ways to tile a 3 by N rectangle with the six tetrominoes except the straight piece, modulo 1,000,000.	Medium7	Dynamic programmingMatrix	No attempts yet	2s	256 MB	Judgeable
Calvinball championshipGiven a valid team-number sequence, compute its 1-based lexicographic rank among all such records for n players, modulo 1000007.	Medium7	CombinatoricsDynamic programming	No attempts yet	1s	64 MB	Judgeable
Calvinball championship, againColor n players with the fewest teams so no disliking pair shares a team, breaking ties by the lexicographically smallest assignment.	Medium7	BacktrackingGraph+1	No attempts yet	1s	256 MB	Judgeable
School CanteenCount length-n menus over k meals with no meal repeated l times in a row, modulo 4000000009.	Medium7	Dynamic programmingMatrix+1	No attempts yet	5s	256 MB	Judgeable
Calvinball team splitSplit up to 16 players into the fewest teams with no disliked pair sharing a team, breaking ties by the smallest assignment sequence.	Medium7	GraphBacktracking+2	No attempts yet	1s	256 MB	Judgeable
Calvinball team assignmentColor a graph of up to 15 players with the fewest colors so no dislike edge shares a color, printing the lexicographically smallest assignment.	Medium7	GraphBacktracking+1	No attempts yet	1s	256 MB	Judgeable
Calvinball team assignmentAssign up to 24 participants to the fewest teams so no disliking pair shares a team, and print the lexicographically smallest optimal assignment.	Medium7	BacktrackingGraph+1	No attempts yet	1s	256 MB	Judgeable