Problems

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Total results29,442 problems

Card Flipping
Medium5
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Induction
Medium5
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gojeonyeon Train Play
Medium5
Dynamic programming, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Eggplant Emoji
Medium5
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dinosaur Game
Medium5
Dynamic programming, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The More Cats, the Better
Medium5
Dynamic programming, Recursion+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sasa's Four-Dimensional Candy Bag
Medium5
Prefix sum, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
OX
Medium5
Bit manipulation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
More dogs are better
Medium5
BFS, Array+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Kickboard Commute to School
Medium5
Binary search, Greedy
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
String Game
Medium5
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Region Coloring
Medium5
Greedy, Array
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Prize Draw
Medium5
Dynamic programming, Matrix+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Attention
Medium5
Dynamic programming, Segment tree
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Rocket Launching
Medium5
Sorting, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Milk Sum
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Asking for Money
Medium5
Graph, DFS+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
City Folding
Medium5
Bit manipulation, Implementation
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
Empty Squares
Medium5
Dynamic programming, Greedy
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
SW Sequence Construction
Medium5
Array, Greedy
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Thanos Hates Josephus
Medium5
Dynamic programming, Simulation
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
I Am Knowledge
Medium5
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Stairs to the Kimbap Heaven
Medium5
BFS, Shortest path
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
PSAT Special Course
Medium5
BFS, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rectangular Pizza
Medium5
Sorting, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Demon King's Castle
Medium5
Union-find, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Strange Array
Medium5
Array, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tree Climbing
Medium5
Dynamic programming, Tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Meeting place 2
Medium5
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
prlong longf
Medium5
Dynamic programming, String matching
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Recruiting New SCCC Members
Medium5
Greedy, Graph
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Was the 2022 APC really that hard?
Medium5
Dynamic programming, Prefix sum
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
K-Won Banknotes
Medium5
Shortest path, Graph
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
You Never Learned Geometry and Vectors?
Medium5
Hash map, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Red, Red, Blue, Blue! Sweet Cotton Candy!
Medium5
Array, Greedy+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Allergen Testing
Medium5
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Power of Divisors
Medium5
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Repetitive String Invention
Medium5
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Maximum GCD
Medium5
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Item Collection
Medium5
Binary search, Prefix sum+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Magic with Cards
Medium5
BFS, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Lunch Time Race
Medium5
Array, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Turn Off the Classroom Lights
Medium5
Dynamic programming, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Math Teacher's Worry (Hard)
Medium5
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hungry (Hard)
Medium5
Bit manipulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Yawned-Zoned
Medium5
Dynamic programming, BFS+1
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Induction
Medium5
Math, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hacking
Medium5
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Waiting for Regrading
Medium5
Backtracking, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ant Sequence
Medium5
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Wall Value
Medium5
BFS, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Filter
Medium5
Math, Recursion+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Binaria
Medium5
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ant Nest by the Lake
Medium5
Dynamic programming
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Lottery Games
Medium5
Combinatorics, Probability+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Strange Draft
Medium5
Sliding window, Queue+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
K-ary Huffman Encoding
Medium5
Greedy, Heap
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
XOR Necklace
Medium5
Dynamic programming, Bit manipulation
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Algospot Design School
Medium5
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ice Cream Machines
Medium5
Greedy, Simulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Cosmic Commute
Medium5
BFS, Graph+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
German Conference for Public Counting
Medium5
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Investigating Frog Behaviour on Lily Pad Patterns
Medium5
Segment tree, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Loop Invariant
Medium5
String, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mischievous Math
Medium5
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Closeness
Medium5
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bank Counter
Medium5
Greedy, Heap+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rectangle Division
Medium5
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fibonacci product
Medium5
Backtracking, Recursion+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Robot Vacuum Cleaner
Medium5
Sorting, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Beautiful Sequences
Medium5
Dynamic programming, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Kadeo Garden
Medium5
Prefix sum, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Loyalty Game
Medium5
Union-find, Simulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Calculating Scores
Medium5
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Making Sticks
Medium5
Dynamic programming, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bullet Hell Game
Medium5
Math, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Every? Only One's Marble
Medium5
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mahjong Tenpai
Medium5
Brute force, Backtracking+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Fibonacci Rectangle
Medium5
Divide and conquer, Recursion+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
What makes a good team?
Medium5
Hash map, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Spell Cards
Medium5
Dynamic programming, Intervals+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Coprime Fibonacci Numbers
Medium5
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Conditionally rich numbers
Medium5
Number theory, Prefix sum+1
No attempts yet
Time limit
0.18s
Memory limit
1024 MB
Judgeable
Burgers
Medium5
Binary search, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Topical
Medium5
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Leaf Cleanup
Medium5
Sorting, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Citadel Hierarchy
Medium5
Tree, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Unwelcome Visitors
Medium5
Prefix sum, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rick's Robe
Medium5
BFS, Graph+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Nightmare Awake
Medium5
Geometry, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Let's Split Up!
Medium5
Binary search, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Interesting celebrations
Medium5
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Code Plagiarism
Medium5
Greedy, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
There Are n Chairs
Medium5
Sorting, Binary search+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Terrifying Palindrome
Medium5
String, Hash map+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Paired Scaring
Medium5
Math, Tree
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pear for Halloween
Medium5
Bit manipulation, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Careful Planning
Medium5
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Reunion with Venom
Medium5
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gifts
Medium5
Greedy, Segment tree+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Card FlippingArrange cards numbered 1 to N in a line so that a chain of moves, each jumping by the flipped card's number, flips every card.	Medium5	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
InductionGiven N dish temperatures (0 to 9) in order, find the fewest button presses on three cyclic zones so each dish has a matching zone.	Medium5	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Gojeonyeon Train PlaySplit a string of K and Y into the fewest consecutive segments, each at most L long, where the K and Y counts differ by at most 1.	Medium5	Dynamic programmingSliding window+2	No attempts yet	1s	1024 MB	Judgeable
Eggplant EmojiGiven N counts, each may be increased by 1, find the maximum possible GCD of the resulting counts.	Medium5	MathNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Dinosaur GameGiven obstacles that need a jump, a slide, or either, find the minimum penalty under separate jump and slide cooldowns, or -1 if no valid sequence exists.	Medium5	Dynamic programmingImplementation	No attempts yet	1s	1024 MB	Judgeable
The More Cats, the BetterGiven N, find the fewest creation or cloning spells that leave exactly N cats, where a cloning spell adds up to the current cat count.	Medium5	Dynamic programmingRecursion+1	No attempts yet	1s	1024 MB	Judgeable
Sasa's Four-Dimensional Candy BagFor each child, find how many of Sasa's candy grabs from the sequence A are needed to reach B_i candies, or report that the child is sent away.	Medium5	Prefix sumBinary search+1	No attempts yet	2s	1024 MB	Judgeable
OXGiven a string of O and X, count the operations needed until every character is X, modulo 1e9+7.	Medium5	Bit manipulationMath	No attempts yet	1s	1024 MB	Judgeable
More dogs are betterGiven N, spell amounts A and B, and forbidden count intervals that reset the dog count to zero, find the fewest casts that reach exactly N dogs.	Medium5	BFSArray+1	No attempts yet	2s	1024 MB	Judgeable
Kickboard Commute to SchoolFind the smallest battery capacity that lets Geondeok reach school at position L from home at 0 while visiting at most K charging stations.	Medium5	Binary searchGreedy	No attempts yet	1s	512 MB	Judgeable
String GameGiven a board of N letters and a word of length M, find the most word letters Geondeok can match by stepping left or right one cell at a time.	Medium5	Dynamic programmingString	No attempts yet	2s	512 MB	Judgeable
Region ColoringGiven a grid of 0, 1, and 2 cells, find the fewest horizontal strokes that reproduce the picture, where strokes may overpaint but never cover a 0 cell.	Medium5	GreedyArray	No attempts yet	1s	512 MB	Judgeable
Prize DrawGiven a board with nails, find the bottom column where a ball most likely ends up when it restarts from the top each time it gets stuck.	Medium5	Dynamic programmingMatrix+1	No attempts yet	1s	512 MB	Judgeable
AttentionCount the ingredient triples whose positions increase in both recipe books, or report that no such triple exists.	Medium5	Dynamic programmingSegment tree	No attempts yet	1s	512 MB	Judgeable
Rocket LaunchingGiven buildings at distances X_i with heights H_i, find for each query T the highest altitude Taro can be at by time T after climbing one ladder.	Medium5	SortingBinary search+1	No attempts yet	2s	1024 MB	Judgeable
Milk SumEach query sets one cow's milk rate to j, and the task is to find the maximum total milk over all unhooking orders.	Medium5	GreedySorting+2	No attempts yet	4s	1024 MB	Judgeable
Asking for MoneyGiven who each person asks for money, find every person whose two requests can both fail because those people already paid someone else.	Medium5	GraphDFS+1	No attempts yet	0.5s	1024 MB	Judgeable
City FoldingGiven N folds and a home section P on a strip of 2^N sections, output the L/R fold sequence that places P at stack height H.	Medium5	Bit manipulationImplementation	No attempts yet	0.1s	1024 MB	Judgeable
Empty SquaresGiven N, the placed tile size K, and E empty squares to its left, find how many squares stay empty after Nico covers as many as possible with the other tiles.	Medium5	Dynamic programmingGreedy	No attempts yet	0.1s	1024 MB	Judgeable
SW Sequence ConstructionBuild a permutation of 1 to N in which each adjacent gap is strictly smaller than the gap before it.	Medium5	ArrayGreedy	No attempts yet	2s	1024 MB	Judgeable
Thanos Hates JosephusFind the last squirrel left when each round keeps the first squirrel, removes the next K-1 clockwise, and the first moves to the right, for N and K up to 10^6.	Medium5	Dynamic programmingSimulation	No attempts yet	0.1s	512 MB	Judgeable
I Am KnowledgeGiven books with a start cost a_i and a finish reward b_i, decide whether some reading order keeps joy from going negative.	Medium5	GreedySorting	No attempts yet	2s	1024 MB	Judgeable
Stairs to the Kimbap HeavenGiven N and K, decide whether Minhee can reach stair N in exactly K actions when tapping stair i moves Minhee to stair i + floor(i/2).	Medium5	BFSShortest path	No attempts yet	1s	512 MB	Judgeable
PSAT Special CourseGiven a graph with one letter per vertex, find the lexicographically smallest string along a shortest path from an S-stamped vertex to an E-stamped vertex.	Medium5	BFSShortest path+2	No attempts yet	2s	512 MB	Judgeable
Rectangular PizzaGiven the cut positions on a W by H pizza, count the slices whose area is at most K.	Medium5	SortingTwo pointers+1	No attempts yet	1s	1024 MB	Judgeable
The Demon King's CastleFor each plot, find the total tax of the connected region of plots no higher than it that contains that plot, with the plot as the castle.	Medium5	Union-findSorting+1	No attempts yet	3s	1024 MB	Judgeable
Strange ArrayGiven an array, determine whether every element lying between two equal values is at most that value.	Medium5	ArrayHash map+1	No attempts yet	1s	1024 MB	Judgeable
Tree ClimbingCount the root-to-leaf paths where each jump from vertex i goes down to a descendant at distance 1 to A_i, modulo 998244353.	Medium5	Dynamic programmingTree+1	No attempts yet	1s	1024 MB	Judgeable
Meeting place 2Given a string S of length N, find the K-th lexicographically smallest string that differs from S in at most one position, or print -1 if there is none.	Medium5	StringImplementation+1	No attempts yet	2s	1024 MB	Judgeable
prlong longfCount the original strings that become the given string when every "int" is replaced with "longlong".	Medium5	Dynamic programmingString matching	No attempts yet	2s	1024 MB	Judgeable
Recruiting New SCCC MembersAssign applicants in descending score order to K groups of capacity X, accepting each one only if all accepted applicants can still be seated, moving earlier ones if needed.	Medium5	GreedyGraph	No attempts yet	2s	1024 MB	Judgeable
Was the 2022 APC really that hard?Count the sequences of N difficulties where each D_i lies in [a_i, b_i] and adjacent values differ by at most K, modulo 1e9+7.	Medium5	Dynamic programmingPrefix sum	No attempts yet	1s	1024 MB	Judgeable
K-Won BanknotesFind the cheapest route from city S to city T on a directed road graph whose total fee is a multiple of K, or report IMPOSSIBLE.	Medium5	Shortest pathGraph	No attempts yet	2s	1024 MB	Judgeable
You Never Learned Geometry and Vectors?Count the pairs of 2D integer vectors whose dot product is zero, where a zero vector counts as perpendicular to every other vector.	Medium5	Hash mapMath	No attempts yet	2s	1024 MB	Judgeable
Red, Red, Blue, Blue! Sweet Cotton Candy!For each interval [l, r], find two R positions followed by two B positions in order inside it, or report -1 if none exist.	Medium5	ArrayGreedy+1	No attempts yet	2s	1024 MB	Judgeable
Allergen TestingGiven n compounds and d days, find the fewest sites needed to identify the one allergen for up to 10^4 queries with n and d up to 10^18.	Medium5	MathImplementation	No attempts yet	1s	2048 MB	Judgeable
Power of DivisorsGiven x up to 10^18, find the smallest n such that n raised to the number of its divisors equals x, or report -1.	Medium5	MathBrute force	No attempts yet	1s	2048 MB	Judgeable
Repetitive String InventionCount the ways to pick two non-overlapping substrings, in order, whose concatenation is a repetitive string (a square) for a string of length up to 800.	Medium5	Dynamic programmingString	No attempts yet	2s	2048 MB	Judgeable
Maximum GCDGiven an array of up to 1e5 positive integers, find the largest d such that repeated modulo operations (never producing 0) can make every element a multiple of d.	Medium5	MathNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Item CollectionGiven N weighted boxes on a grid and Q axis-parallel moves from (1, 1), find the total items collected along the path.	Medium5	Binary searchPrefix sum+1	No attempts yet	3s	1024 MB	Judgeable
Magic with CardsGiven a deck of 2n cards, find the fewest riffle and scuffle shuffles that move the card at position i to position j, or report -1.	Medium5	BFSGraph+1	No attempts yet	2s	1024 MB	Judgeable
Lunch Time RaceGiven n floors with m classrooms each and k classes at set positions, find the class that reaches the cafeteria door first, with the smallest number on ties.	Medium5	ArrayMath+1	No attempts yet	1s	1024 MB	Judgeable
Turn Off the Classroom LightsFind the least time for Jinseo to visit every lit classroom from floor 1 and return to a staircase there, using the fewest stairs first.	Medium5	Dynamic programmingImplementation	No attempts yet	1s	1024 MB	Judgeable
Math Teacher's Worry (Hard)Given a positive integer n, factor n x^2 + (n+1)x - (n+2) over the integers and print (a, b, c, d), or -1 if no factorization exists.	Medium5	MathNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Hungry (Hard)For each m up to 10^18, find the pair x <= y whose 2^x + 2^y is closest to m (smallest on ties), and print x and y.	Medium5	Bit manipulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Yawned-ZonedPlace exactly W dividers between columns so the largest group of students who yawn from one starting student is as small as possible, then print that size.	Medium5	Dynamic programmingBFS+1	No attempts yet	2.5s	1024 MB	Judgeable
InductionGiven k, find the fewest operations (double the value or subtract 1) to reach k from 1, printing "Wrong proof!" if k is unreachable.	Medium5	MathGreedy+1	No attempts yet	1s	512 MB	Judgeable
HackingPick X computers to hack at time 0 to maximize total money before security reaches them, or print -1 if an uninfectable computer earns money.	Medium5	GraphBFS+2	No attempts yet	2s	1024 MB	Judgeable
Waiting for RegradingGiven an answer key and an OMR sheet, find the most matches after at most K pull or shift operations on the sheet.	Medium5	BacktrackingSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Ant SequenceGiven N (at most 100), find the largest digit in the N-th term of the look-and-say sequence that starts from 1.	Medium5	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Wall ValueGiven a grid with walls, N pieces, and a destination, find the sum of shortest distances and the total drop in that sum when each wall is removed.	Medium5	BFSGraph+1	No attempts yet	2s	512 MB	Judgeable
The FilterGiven N, list every x from 0 to N such that x/N lies in the Cantor set, in increasing order.	Medium5	MathRecursion+1	No attempts yet	2s	1024 MB	Judgeable
BinariaCount the binary strings of length N whose length-K sliding window sums match the given sequence, modulo 1000003.	Medium5	CombinatoricsMath+1	No attempts yet	1s	1024 MB	Judgeable
Ant Nest by the LakePlace ants on a circle of N rooms, each with C_i side chambers, so no two directly connected occupied places touch. Find the maximum number of ants.	Medium5	Dynamic programming	No attempts yet	2s	1024 MB	Judgeable
Lottery GamesGiven several lottery tickets, find which ticket gives the highest chance of matching at least K numbers, listing all tied tickets in order.	Medium5	CombinatoricsProbability+1	No attempts yet	1s	1024 MB	Judgeable
Strange DraftFor each test case, find the K consecutive players whose best defensive ability at each of the nine positions sums to the largest total.	Medium5	Sliding windowQueue+1	No attempts yet	1s	1024 MB	Judgeable
K-ary Huffman EncodingGiven N character frequencies, find the minimum total length of a K-ary prefix-free encoding of the weighted string.	Medium5	GreedyHeap	No attempts yet	1s	1024 MB	Judgeable
XOR NecklaceGiven a necklace of N beads, remove some beads to maximize the sum of XORs between each pair of adjacent beads around the cycle.	Medium5	Dynamic programmingBit manipulation	No attempts yet	3s	1024 MB	Judgeable
Algospot Design SchoolGiven rectangles for drawings on the front and back of a sheet, find the maximum number of drawings you can cut out as separate pieces.	Medium5	GraphDFS	No attempts yet	1s	1024 MB	Judgeable
Ice Cream MachinesGiven a queue of flavour requests and k machines, find the fewest machine cleanings needed to serve every customer in order.	Medium5	GreedySimulation+1	No attempts yet	2s	1024 MB	Judgeable
Cosmic CommuteFind the expected minimum number of light trains from planet 1 to planet n when one random wormhole teleport is allowed.	Medium5	BFSGraph+1	No attempts yet	3s	1024 MB	Judgeable
German Conference for Public CountingGiven n, find the fewest digit signs needed so every number from n down to 0 can be displayed with them.	Medium5	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Investigating Frog Behaviour on Lily Pad PatternsFrogs sit on sorted lily pads and each jump lands on the nearest empty pad to the right. Output the landing pad for every recorded jump.	Medium5	Segment treeSimulation	No attempts yet	1s	1024 MB	Judgeable
Loop InvariantGiven a balanced parentheses string read as a circle, find a cyclic rotation that is balanced and differs from the original, or print no.	Medium5	StringPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Mischievous MathGiven d, output distinct a, b, c from 1 to 100, all different from d, so that no expression using each at most once with +, -, *, / and parentheses equals d.	Medium5	MathBrute force	No attempts yet	1s	1024 MB	Judgeable
ClosenessDecide whether two strings can be made equal by cyclically shifting adjacent letter pairs, after each of Q single-letter updates to one string.	Medium5	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Bank CounterGiven N people, each with a deadline T_i and a job time P_i, find the maximum number who can finish their jobs when served one at a time.	Medium5	GreedyHeap+1	No attempts yet	1s	1024 MB	Judgeable
Rectangle DivisionGiven a board of size a by b, k cuts, and m rectangles, find the horizontal and vertical cut counts h and v, preferring fewer horizontal cuts, or print -1.	Medium5	MathNumber theory	No attempts yet	1s	1024 MB	Judgeable
Fibonacci productGiven n, count the ways to write it as a product of Fibonacci numbers greater than 1, where order does not matter.	Medium5	BacktrackingRecursion+1	No attempts yet	1s	1024 MB	Judgeable
Robot Vacuum CleanerGiven a k by k robot and a sequence of directional moves, find the total area swept by the robot over all its positions.	Medium5	SortingImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Beautiful SequencesCount length-n sequences from the set A (values 1 to 8) where any two equal values x are more than x positions apart, modulo 1e9+7.	Medium5	Dynamic programmingBit manipulation	No attempts yet	1s	1024 MB	Judgeable
Kadeo GardenFind the minimum blur sum over all valid placements of the car and camping trailer, where the trailer touches the car in one of three shapes.	Medium5	Prefix sumBrute force+1	No attempts yet	1s	1024 MB	Judgeable
Loyalty GameEach type 1 query pours x liters from student i onward, with each student drinking up to their capacity, and type 2 asks a student's total drunk amount.	Medium5	Union-findSimulation+1	No attempts yet	2s	1024 MB	Judgeable
Calculating ScoresGiven a tree with node scores, answer each query for node v's total score when node r is the root, which is the sum of scores in v's subtree.	Medium5	TreeDFS+1	No attempts yet	2s	1024 MB	Judgeable
Making SticksFor each query length L, count the ways to reach L from some base stick A by multiplying by a sequence of integers k of at least 2.	Medium5	Dynamic programmingNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Bullet Hell GameDecide whether a character on an N by M grid can dodge bullets that chase it in 8 directions for T seconds, moving first each second.	Medium5	MathSimulation	No attempts yet	1s	1024 MB	Judgeable
Every? Only One's MarbleSimulate a solo Monopoly game on a ring board with gold keys, traps, and a fund, then report whether all city squares get bought before the dice run out.	Medium5	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Mahjong TenpaiGiven 13 mahjong tiles, check whether the hand is in tenpai and list every tile kind that completes a valid 14-tile win.	Medium5	Brute forceBacktracking+1	No attempts yet	2s	1024 MB	Judgeable
Fibonacci RectangleGiven a picture of width a and height b built from nested Fibonacci rectangles and a point (x, y), find the index of the smallest Fibonacci rectangle containing that point.	Medium5	Divide and conquerRecursion+1	No attempts yet	1s	1024 MB	Judgeable
What makes a good team?Given N people, each with a skill and one of 60 day pillars, pick three to maximize the team score from pairwise stem and branch tables plus skill sums.	Medium5	Hash mapBrute force+1	No attempts yet	1s	1024 MB	Judgeable
Spell CardsGiven N cards with mana costs, merge adjacent pairs where each merge costs the sum and leaves the larger value. Find the minimum total cost.	Medium5	Dynamic programmingIntervals+1	No attempts yet	1s	1024 MB	Judgeable
Coprime Fibonacci NumbersFor each n up to 1e9, count the Fibonacci numbers F_1 to F_(n-1) that are coprime to F_n.	Medium5	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
Conditionally rich numbersFor each query (L, R, V), count the integers N in [L, R] whose divisor sum without N itself is greater than V.	Medium5	Number theoryPrefix sum+1	No attempts yet	0.18s	1024 MB	Judgeable
BurgersGiven stock x_i and the per-ingredient needs a_i and b_i of two burger recipes, find the maximum number of burgers that can be made.	Medium5	Binary searchMath+1	No attempts yet	1s	1024 MB	Judgeable
TopicalGiven knowledge requirements and gains for n modules across k topics, find the maximum number of modules Benson can complete in some order.	Medium5	GreedySorting+1	No attempts yet	1s	1024 MB	Judgeable
Leaf CleanupGiven n pile sizes, choose a range of k consecutive integers within 1 to c that minimizes the total size of the piles falling inside it.	Medium5	SortingPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Citadel HierarchyGiven a rooted tree of Ricks with Mortys as leaves, decide whether each Rick can reorder its direct subordinates so the bottom-level Mortys end up sorted.	Medium5	TreeDFS+1	No attempts yet	1s	1024 MB	Judgeable
Unwelcome VisitorsGiven a scrambled log of arrivals and departures for n categories, find the minimum and maximum possible number of distinct visitors per category.	Medium5	Prefix sumGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Rick's RobeGiven a graph with wet vertices and existing holes, find the vertex for a new hole that minimizes the time for every wet point to reach its nearest hole.	Medium5	BFSGraph+1	No attempts yet	3s	1024 MB	Judgeable
Nightmare AwakeGiven a circle, a line, and two points, decide whether rotating the circle can make the segment through the two points parallel to the line.	Medium5	GeometryMath	No attempts yet	1s	1024 MB	Judgeable
Let's Split Up!Split n people into two groups, each with one leader and one room, to minimize the largest danger akb, and print the minimum with the assignment.	Medium5	Binary searchMath+1	No attempts yet	1s	1024 MB	Judgeable
Interesting celebrationsCount the subsequences of string s that equal one of the words seq_1 to seq_26, modulo 998244353.	Medium5	Dynamic programmingString	No attempts yet	1s	1024 MB	Judgeable
Code PlagiarismGiven strings s and t, decide whether t can remain after repeatedly deleting any two adjacent characters from s.	Medium5	GreedyTwo pointers+1	No attempts yet	1s	1024 MB	Judgeable
There Are n ChairsPick chairs whose total width reaches H so that the largest height gap between neighbors in the row is as small as possible.	Medium5	SortingBinary search+1	No attempts yet	1s	1024 MB	Judgeable
Terrifying PalindromeOrder n equal-length strings so their concatenation is a palindrome, or report -1 if no such order exists.	Medium5	StringHash map+1	No attempts yet	1.5s	1024 MB	Judgeable
Paired ScaringGiven n and k, count the children in only one pair in a tree where every other child has k pairs, or print -1 if impossible.	Medium5	MathTree	No attempts yet	1s	1024 MB	Judgeable
Pear for HalloweenGiven values on the nodes of a tree, XOR the sums a_i + a_j over every pair of nodes i < j.	Medium5	Bit manipulationMath+2	No attempts yet	1s	1024 MB	Judgeable
Careful PlanningGiven n numbers, find the one-to-one reassignment of digits 0 to 9 that maximizes their sum, with no leading zeros allowed.	Medium5	Dynamic programmingBit manipulation+1	No attempts yet	1s	1024 MB	Judgeable
Reunion with VenomGiven three hormone levels, find the minimum number of operations (decrease one by 1, increase the other two by 1) that make all three equal, or report -1.	Medium5	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
GiftsGifts pass in order along a belt past N machines with size limits; find the minimum seconds to wrap all M gifts, given the belt moves one step per second.	Medium5	GreedySegment tree+1	No attempts yet	3s	1024 MB	Judgeable