Interview core

Mediums from real onsites

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Total results3,617 problems

Stacking Cubes
Medium6
Array, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Building Snowmen
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Letter Game
Medium6
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Little Shop of Flowers
Medium6
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Flatten
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Recycling Proteins
Medium6
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dividing the Path
Medium6
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cleaning Shifts
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Journey
Medium6
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tickets
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cutting Out of Factorials
Medium6
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Prime Scrabble
Medium6
Brute force, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Õhne vanaraamatupood
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1023 MB
Judgeable
Roads
Medium6
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Puzzle of Numbers
Medium6
Backtracking, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Swimming Pool
Medium6
Heap, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Operator Signs
Medium6
Dynamic programming, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Turning a Tree
Medium6
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dragon
Medium6
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rock, Paper, Scissors
Medium6
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Liars
Medium6
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Television
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Passengers
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Airplane Passengers
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Vice City
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Food Cubes
Medium6
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Remove Redundant Parentheses
Medium6
Stack, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Counting Rectangles
Medium6
Geometry, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gene Function
Medium6
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Moving Tables
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
String Folding
Medium6
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Flip Game
Medium6
Brute force, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Binary Search
Medium6
Binary search, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Garland
Medium6
Math, Binary search+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Loan
Medium6
Binary search, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Defragment
Medium6
Greedy, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Four Integers Summing to Zero
Medium6
Hash map, Sorting+2
No attempts yet
Time limit
12s
Memory limit
1024 MB
Judgeable
Graveyard Design
Medium6
Two pointers, Math+2
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
ATM Game
Medium6
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Embassy
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fractal Cake
Medium6
Divide and conquer, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Citystar
Medium6
Sorting, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Soccer
Medium6
Dynamic programming, Probability+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jamie's Contact Groups
Medium6
Binary search, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Military Recruit
Medium6
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Period of a Repeating Fraction
Medium6
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Virus
Medium6
String, String matching+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Four Gate Push
Medium6
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Spam
Medium6
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Colored Stones
Medium6
Dynamic programming, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Burger, French Fries, Soft Drink
Medium6
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Taxi!
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Transitive Closure
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Spreadsheet
Medium6
Implementation, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jack's Socks
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
The Fifth Dimension
Medium6
Graph, Combinatorics
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Counting-Out Rhyme
Medium6
Simulation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Speleology
Medium6
Graph, Dynamic programming+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Three-Coloring of Binary Trees
Medium6
Tree, DFS+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Water
Medium6
Heap, BFS+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Cheap Travels
Medium6
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lecture Halls Reservation
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Zeros and Ones - 2
Medium6
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Right-Turn Drivers' Club
Medium6
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Concatenation of Words
Medium6
Dynamic programming, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Backpack
Medium6
Dynamic programming, Tree+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rooks
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Kangaroos
Medium6
Intervals, Sorting+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Drilling
Medium6
Dynamic programming, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Conference
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Inversions
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bracket Expressions
Medium6
Stack, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Spaceships
Medium6
Sorting, Binary search
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Domino
Medium6
Greedy, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Number of Longest Increasing Subsequences
Medium6
Dynamic programming, Segment tree
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Longest Common Increasing Subsequence
Medium6
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Eurozwrotnica
Medium6
Queue, Greedy
No attempts yet
Time limit
2.5s
Memory limit
128 MB
Judgeable
Program
Medium6
Binary search, Intervals+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Reservoir
Medium6
Shortest path, Heap+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Leet
Medium6
Backtracking, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Golf Courses
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Boggle
Medium6
Trie, DFS+1
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Passwords
Medium6
Combinatorics, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Metal
Medium6
Binary search, Greedy+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Circleland
Medium6
Greedy, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Wormholes
Medium6
Backtracking, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Longest Arithmetic Progression
Medium6
Dynamic programming, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Dueling GPSs
Medium6
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
IOI Manju
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Surveillance Cameras
Medium6
Greedy, Intervals+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Orchard
Medium6
Matrix, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Mascot Song
Medium6
Array, Simulation
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
King Gruff
Medium6
Shortest path, Sorting+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Expected Ultimate Damage
Medium6
Probability, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Quality of Living
Medium6
Binary search, Prefix sum+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Amanda Lounges
Medium6
Graph, BFS
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Ranks in groups
Medium6
Union-find, Sorting+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Help Cupid
Medium6
Dynamic programming, Sorting
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Matryoshka Dolls
Medium6
Dynamic programming, Sorting
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Bulletproof Glass Testing Budget
Medium6
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Stacking CubesGiven a stacking pattern as non-increasing rows with non-increasing columns, print its left and right rotations as corner stackings.	Medium6	ArrayImplementation+2	No attempts yet	1s	128 MB	Judgeable
Building SnowmenGiven snowball diameters, find the maximum number of triples where each triple's sizes satisfy the stacking ratio inequalities.	Medium6	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Letter GameGiven up to 7 collected letters and a dictionary, find all words or pairs of words with the maximum total letter-value score, using each collected letter at most as often as it appears.	Medium6	StringHash map+2	No attempts yet	1s	512 MB	Judgeable
Little Shop of FlowersPlace F ordered bunches into a row of V vases to maximize total aesthetic value, then output the lexicographically smallest optimal assignment.	Medium6	Dynamic programming	No attempts yet	1s	128 MB	Judgeable
FlattenDistribute chips between neighboring piles at a cost equal to the chips moved, and find the minimum total transferred to make all piles equal.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Recycling ProteinsGiven a source and target chain of amino acids, compute the minimum cost to convert one into the other using delete, insert, and replace with per-type costs.	Medium6	Dynamic programmingString	No attempts yet	1s	128 MB	Judgeable
Dividing the PathPartition the segment [0, L] into consecutive pieces of even length between 2A and 2B so no cut lands strictly inside any cow's interval, and minimize the number of pieces, or report that no partition exists.	Medium6	Dynamic programmingPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Cleaning ShiftsCover shifts 1 through T with the fewest intervals, where each interval covers a contiguous range of shifts. Return the minimum number of intervals or -1.	Medium6	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
JourneyGiven a weighted tree, a start city k, and a set of target cities, find the length of the shortest walk from k that visits every target at least once.	Medium6	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
TicketsSplit L pages of non-increasing popularity into D contiguous channel blocks to minimize the popularity-weighted sum of within-block delay positions, breaking ties by the lexicographically smallest block boundaries.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Cutting Out of FactorialsGiven k from 2 to 500, remove the fewest of 1!, 2!, ..., k! so the remaining product is a perfect square, and report that count.	Medium6	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Prime ScrabbleGiven up to 8 digit tiles, choose a placement order and direction to maximize the sum of prime-reading sums earned minus the values of unplaced tiles.	Medium6	Brute forceMath+2	No attempts yet	1s	1024 MB	Judgeable
Õhne vanaraamatupoodSimulate bots that repeatedly recompute their book price from the previous day's average, and print every bot's price on the morning of day T.	Medium6	ImplementationSimulation+2	No attempts yet	1s	1023 MB	Judgeable
RoadsGiven a graph with N cities and M edges, add exactly K new non-duplicate edges to minimize and maximize the resulting number of connected components.	Medium6	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Puzzle of NumbersGiven three digit-and-star patterns for A, B, and C with A + B = C, fill the stars to build the smallest valid equation.	Medium6	BacktrackingMath+2	No attempts yet	1s	128 MB	Judgeable
Swimming PoolGiven an m by n grid of tower heights, find the total volume of water trapped among the towers when the grid is flooded from the outside.	Medium6	HeapBFS+2	No attempts yet	1s	128 MB	Judgeable
Operator SignsInsert + or - between adjacent numbers so the left-to-right value equals the target, keeping every partial result within 10000, and print the lexicographically smallest expression.	Medium6	Dynamic programmingBacktracking+2	No attempts yet	1s	1024 MB	Judgeable
Turning a TreeReroot a given ordered tree at a specified leaf so the counter-clockwise order of neighbors at each node stays the same, then print the new tree.	Medium6	TreeDFS+2	No attempts yet	1s	1024 MB	Judgeable
DragonPick two disjoint blocks of at most K consecutive heads each in a row of N heads to maximize the total fire power removed.	Medium6	Dynamic programmingPrefix sum+2	No attempts yet	1s	1024 MB	Judgeable
Rock, Paper, ScissorsGiven how many times each player threw rock, paper, and scissors, pair the throws to find the maximum and minimum possible score for Vilius.	Medium6	GreedyMath+2	No attempts yet	1s	1024 MB	Judgeable
LiarsGiven claims that candidate a says candidate b lies or tells the truth, decide whether candidates can be split into liars and truth-tellers consistently.	Medium6	GraphBFS+2	No attempts yet	1s	1024 MB	Judgeable
TelevisionGiven N intervals on a line, choose the fewest intervals so that every point covered by any interval is covered by a chosen one, then print that count.	Medium6	GreedySorting+2	No attempts yet	1s	1024 MB	Judgeable
PassengersGiven each request's row and earliest time, find the least total time for the attendant to serve all and return to row 1.	Medium6	Dynamic programmingGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Airplane PassengersGiven requests at row a made no earlier than minute b, find the minimum minutes for an attendant starting at row 1 to reach every request row on time.	Medium6	Dynamic programmingSorting+2	No attempts yet	1s	1024 MB	Judgeable
Vice CityFind the fastest route from PayPhone to WKCharriot, where travel time depends on the vehicle you drive and each vehicle swap costs one minute.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Food CubesCount the empty unit cells trapped inside a set of food cubes, where a hole is a maximal face-connected empty region that cannot reach the outside.	Medium6	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
Remove Redundant ParenthesesGiven valid arithmetic expressions over single uppercase variables with + and -, remove every matching parenthesis pair whose removal keeps the expression's value unchanged.	Medium6	StackString+2	No attempts yet	1s	128 MB	Judgeable
Counting RectanglesCount rectangles whose four corners are all intersection points of horizontal and vertical segments in a figure.	Medium6	GeometryHash map+2	No attempts yet	1s	128 MB	Judgeable
Gene FunctionAlign two DNA sequences by inserting blanks to maximize the sum of position-wise match values from a given table.	Medium6	Dynamic programmingString	No attempts yet	1s	128 MB	Judgeable
Moving TablesEach move occupies a corridor segment; find the minimum number of 10-minute rounds so that overlapping segments never share a round.	Medium6	GreedySorting+1	No attempts yet	1s	128 MB	Judgeable
String FoldingFind the length of the shortest folded sequence, using repeat counts like 3(AB), that unfolds to the given uppercase string.	Medium6	Dynamic programmingString	No attempts yet	2s	128 MB	Judgeable
Flip GameFind the minimum number of flips to turn all 16 pieces white or all black, where each move flips a chosen cell and its orthogonal neighbors.	Medium6	Brute forceBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Binary SearchFind every array length N for which this binary search on a sorted array reports finding x at index i after exactly L comparisons.	Medium6	Binary searchMath+1	No attempts yet	1s	128 MB	Judgeable
GarlandGiven the leftmost height A and the sag rule H_i = (H_{i-1}+H_{i+1})/2 - 1, find the smallest rightmost height B so all heights stay nonnegative.	Medium6	MathBinary search+1	No attempts yet	1s	128 MB	Judgeable
LoanFind the smallest first annual payment that clears a loan in exactly K years, and output the schedule of equal or one-cent-decreasing yearly payments grouped by amount.	Medium6	Binary searchSimulation+2	No attempts yet	1s	128 MB	Judgeable
DefragmentGiven files spread over N disk clusters, find the minimum number of single-cluster moves to place them contiguously in order, with file i starting after file i-1.	Medium6	GreedyArray+2	No attempts yet	1s	128 MB	Judgeable
Four Integers Summing to ZeroCount the number of index tuples (a, b, c, d) with A[a] + B[b] + C[c] + D[d] = 0, given four arrays of size n.	Medium6	Hash mapSorting+2	No attempts yet	12s	1024 MB	Judgeable
Graveyard DesignFind all runs of consecutive positive integers whose squares sum to a given n up to 10^14, and list each run in order of its smallest element.	Medium6	Two pointersMath+2	No attempts yet	2s	64 MB	Judgeable
ATM GameGiven two bill denominations a and b and an amount S, find non-negative counts of each summing to S with the fewest total bills, or report Impossible.	Medium6	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
EmbassyOrder N people in a queue to minimize the total fee paid for those who finish after their train departure time.	Medium6	GreedySorting+1	No attempts yet	1s	128 MB	Judgeable
Fractal CakePrint the chocolate pattern of a rectangular window in a 2^(N+1) square grid built by recursively darkening the middle 2x2 of every 4x4 block N times.	Medium6	Divide and conquerRecursion+2	No attempts yet	1s	128 MB	Judgeable
CitystarFor each street, find the five house numbers whose span (max minus min plus 1) is smallest, breaking ties by the smallest house numbers.	Medium6	SortingSliding window+2	No attempts yet	1s	128 MB	Judgeable
SoccerGiven 16 teams, a fixed bracket, and pairwise win probabilities, compute each team's probability of winning the single-elimination tournament.	Medium6	Dynamic programmingProbability+2	No attempts yet	1s	128 MB	Judgeable
Jamie's Contact GroupsAssign each of N friends to one of M allowed groups so that every friend lands in exactly one group and the largest group size is as small as possible.	Medium6	Binary searchGraph+2	No attempts yet	1s	128 MB	Judgeable
Military RecruitGiven a directed weighted graph, find the smallest D so that at least p percent of ordered pairs of distinct sites have a shortest-path distance of at most D.	Medium6	Shortest pathGraph+2	No attempts yet	1s	128 MB	Judgeable
Period of a Repeating FractionGiven base b, numerator x and denominator y in that base, find the length of the repeating cycle when x/y is written in base b.	Medium6	MathNumber theory+1	No attempts yet	1s	128 MB	Judgeable
VirusDecide whether every one of N integer sequences shares some contiguous fragment of length at least K, counting reversals as the same fragment.	Medium6	StringString matching+2	No attempts yet	1s	128 MB	Judgeable
Four Gate PushGiven mineral and gas budgets and per-unit strengths, maximize total strength over non-negative counts of three unit types.	Medium6	Dynamic programmingMath+1	No attempts yet	1s	128 MB	Judgeable
SpamCount how many plain-text messages encode to the same spam encoding as a given message.	Medium6	Dynamic programmingString	No attempts yet	1s	128 MB	Judgeable
Colored StonesRemove the fewest stones so that in the remaining row every color appears in one contiguous block.	Medium6	Dynamic programmingBit manipulation	No attempts yet	1s	128 MB	Judgeable
Burger, French Fries, Soft DrinkCount the ways to cut a B/F/S stream into N consecutive blocks where every block has equal positive counts of each letter, or report Impossible.	Medium6	Dynamic programmingPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Taxi!Given a bidirectional weighted graph where each road has a traversal time and a fare, find the minimum total time from s to d whose total fare stays within budget r.	Medium6	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Transitive ClosureCount off-diagonal pairs (X, Y) with a directed path from X to Y in a graph of up to 2500 vertices and 10000 edges.	Medium6	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
SpreadsheetEvaluate a small 9x26 spreadsheet where each cell holds an integer expression with +, -, *, / and cell references, reporting 1000000 if cell A1 is part of a circular reference.	Medium6	ImplementationDFS+2	No attempts yet	1s	128 MB	Judgeable
Jack's SocksGiven an undirected graph of similar socks, decide whether a perfect matching exists and is unique, and print that matching if it is.	Medium6	GraphDFS+2	No attempts yet	1s	512 MB	Judgeable
The Fifth DimensionCount ordered simple paths with 6 distinct vertices and 5 edges in an undirected graph.	Medium6	GraphCombinatorics	No attempts yet	1s	128 MB	Judgeable
Counting-Out RhymeGiven the order children leave a Josephus-style circle, find the smallest rhyme length k that produces exactly that leaving order, or report none exists.	Medium6	SimulationBrute force+2	No attempts yet	1s	128 MB	Judgeable
SpeleologyGiven a DAG where chambers are numbered top to bottom, find the maximum number of downward paths from chamber 1 to chamber n that use distinct first corridors and distinct last corridors.	Medium6	GraphDynamic programming+2	No attempts yet	3s	512 MB	Judgeable
Three-Coloring of Binary TreesGiven a binary tree as a digit specification, color each node red, green, or blue so adjacent nodes differ and siblings differ, then report the maximum and minimum number of green nodes.	Medium6	TreeDFS+2	No attempts yet	3s	128 MB	Judgeable
WaterGiven a grid of cuboid heights, find the total volume of water trapped in the depressions after rain, where water cannot escape past the grid boundary.	Medium6	HeapBFS+2	No attempts yet	3s	128 MB	Judgeable
Cheap TravelsPick a sequence of hotels so consecutive stops are at most 800 km apart, minimizing total price (ties: fewest nights), and also minimizing nights (ties: lowest price).	Medium6	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
Lecture Halls ReservationChoose a set of non-overlapping intervals (open at both ends) to maximize the total length covered, given n up to 10000 and times up to 30000.	Medium6	Dynamic programmingSorting+2	No attempts yet	1s	256 MB	Judgeable
Zeros and Ones - 2For each N, output the smallest positive multiple of N whose decimal digits are only 0 and 1, or BRAK if none exists.	Medium6	BFSGraph+2	No attempts yet	1s	256 MB	Judgeable
The Right-Turn Drivers' ClubOn a grid with blocked cells, find the shortest A-to-B path that never turns left or makes a U-turn, counting squares visited.	Medium6	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
The Concatenation of WordsCount the increasing selections of given words whose concatenation equals a pattern, capped at 1000000, and print the lexicographically smallest selection.	Medium6	Dynamic programmingString+1	No attempts yet	1s	128 MB	Judgeable
BackpackChoose a set of items whose total mass is at most p, where each chosen item requires its named lower-indexed prerequisite to be chosen too.	Medium6	Dynamic programmingTree+1	No attempts yet	1s	128 MB	Judgeable
RooksComplete a partially filled n by n board to a full non-attacking rook placement, choosing the lexicographically smallest completion.	Medium6	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
KangaroosFor each lens interval, find the longest contiguous block of sighting intervals that all overlap it.	Medium6	IntervalsSorting+2	No attempts yet	5s	128 MB	Judgeable
DrillingGiven drilling costs at n positions along a segment, find the minimum worst-case total time to locate the reservoir boundary using adaptive queries.	Medium6	Dynamic programmingBinary search+2	No attempts yet	1s	128 MB	Judgeable
ConferenceGiven per-presentation ticket prices, room capacity and room rent, and group reservations, choose how many tickets to cancel to maximize revenue minus rent.	Medium6	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
InversionsCount permutations of size n that have exactly k inversions, modulo 30011, using the Mahonian number recurrence with a sliding window over prefix sums.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Bracket ExpressionsThe task is to count substrings of a bracket string that are correct bracket sequences.	Medium6	StackDynamic programming	No attempts yet	1s	512 MB	Judgeable
SpaceshipsThe program counts triples with one module from each factory whose fuel-weighted range tops half the best possible range.	Medium6	SortingBinary search	No attempts yet	1s	512 MB	Judgeable
DominoChoose the smallest chain from the first to the last domino where each kept tile is taller than the distance to the next kept tile.	Medium6	GreedyPrefix sum+1	No attempts yet	1s	128 MB	Judgeable
Number of Longest Increasing SubsequencesCount how many strictly increasing subsequences of the given sequence attain the maximum possible length, modulo m.	Medium6	Dynamic programmingSegment tree	No attempts yet	1s	128 MB	Judgeable
Longest Common Increasing SubsequenceFind the length of the longest strictly increasing sequence that is a subsequence of both given sequences.	Medium6	Dynamic programmingArray	No attempts yet	1s	128 MB	Judgeable
EurozwrotnicaDecide whether the arriving train order can be split across two FIFO tracks so all trains leave in increasing order.	Medium6	QueueGreedy	No attempts yet	2.5s	128 MB	Judgeable
ProgramCount the starting values from 1 to M that reach exactly A after running the given add, subtract, multiply, and floor-divide program.	Medium6	Binary searchIntervals+1	No attempts yet	1s	128 MB	Judgeable
ReservoirRaise water from the pump across edge-adjacent cells of bounded height to the highest level that floods no tree, and report the flooded count.	Medium6	Shortest pathHeap+1	No attempts yet	1s	128 MB	Judgeable
LeetDecide whether the plain word can be split so each distinct letter maps to one fixed leet block of length at most k.	Medium6	BacktrackingString+1	No attempts yet	2s	128 MB	Judgeable
Golf CoursesPick course sites and assign every client to a built course to minimize building plus connection costs within capacities.	Medium6	Dynamic programmingSorting+1	No attempts yet	1s	128 MB	Judgeable
BoggleFind all dictionary words on each 4x4 Boggle board with 8-direction steps without reuse, then report the total score, longest word, and word count.	Medium6	TrieDFS+1	No attempts yet	10s	512 MB	Judgeable
PasswordsPrint the K-th distinct string formed by concatenating every permutation of N equal-length strings in ASCII order.	Medium6	CombinatoricsSorting+1	No attempts yet	1s	128 MB	Judgeable
MetalSort the deposits by x, split them into at most k contiguous groups, and place one horizontal tunnel per group to minimize the largest vertical distance.	Medium6	Binary searchGreedy+1	No attempts yet	5s	256 MB	Judgeable
CirclelandYou start at room R1 on a corridor cycle and visit every room, then leave through any exit while walking the shortest total corridor distance.	Medium6	GreedyPrefix sum+1	No attempts yet	1s	256 MB	Judgeable
WormholesCount the pairings of N wormholes into pairs so that walking right and teleporting through pairs can loop forever from some start.	Medium6	BacktrackingGraph+1	No attempts yet	1s	128 MB	Judgeable
Longest Arithmetic ProgressionFind the length of the longest subsequence of the given sorted list that forms an arithmetic progression.	Medium6	Dynamic programmingArray	No attempts yet	2s	1024 MB	Judgeable
Dueling GPSsFind a route from intersection 1 to N that minimizes the count of roads lying off either GPS shortest path to the farm.	Medium6	Shortest pathGraph	No attempts yet	1s	128 MB	Judgeable
IOI ManjuChoose boxes and fill them with the priciest manju so packed value minus box cost is as large as possible.	Medium6	Dynamic programmingSorting+1	No attempts yet	1s	256 MB	Judgeable
Surveillance CamerasChoose the fewest circular arcs that cover all N rooms on a circle, or report impossible.	Medium6	GreedyIntervals+1	No attempts yet	4s	512 MB	Judgeable
OrchardPick one rectangle for Bert to minimize the bananas left outside it plus the apples inside it.	Medium6	MatrixPrefix sum+1	No attempts yet	2s	512 MB	Judgeable
Mascot SongMaintain an array under point updates and left rotations, reporting the number of maximal strictly increasing runs after each query.	Medium6	ArraySimulation	No attempts yet	1s	32 MB	Judgeable
King GruffFor each query, sum the shutdown costs of roads lying on some A to B path whose total length is at most D.	Medium6	Shortest pathSorting+1	No attempts yet	2s	256 MB	Judgeable
Expected Ultimate DamageThe champion casts the ultimate N times with random doubling or plus-one effects on attack and ability, and you compute the expected sum of their product.	Medium6	ProbabilityMath	No attempts yet	1s	256 MB	Judgeable
Quality of LivingFind the smallest median among all H by W subrectangles of a grid holding the numbers 1 to R times C.	Medium6	Binary searchPrefix sum+1	No attempts yet	5s	256 MB	Judgeable
Amanda LoungesChoose the fewest airports for lounges so every route has zero, exactly one, or two lounges as required.	Medium6	GraphBFS	No attempts yet	2s	256 MB	Judgeable
Ranks in groupsGroups of students merge together and each query asks for the score rank of one student inside its current group.	Medium6	Union-findSorting+1	No attempts yet	5s	256 MB	Judgeable
Help CupidGiven N time zones, split everyone into pairs to minimize the total circular hour difference.	Medium6	Dynamic programmingSorting	No attempts yet	3s	256 MB	Judgeable
Matryoshka DollsChoose and nest the most dolls so each doll carries its own weight plus every doll inside it.	Medium6	Dynamic programmingSorting	No attempts yet	1s	256 MB	Judgeable
Bulletproof Glass Testing BudgetCompute the minimum worst-case budget to find the exact breaking distance when each bullet and each broken pane costs money.	Medium6	Dynamic programming	No attempts yet	1s	256 MB	Judgeable