Problems

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Total results29,447 problems

American Tour
Medium5
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Structure of Balanced Networks
Medium5
Graph, Math+2
No attempts yet
Time limit
5s
Memory limit
16 MB
Judgeable
Magnus
Medium5
Greedy, String+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sajam (Christmas Fair)
Medium5
Matrix, Bit manipulation+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Fine Dining
Medium5
Shortest path, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Teamwork
Medium5
Dynamic programming, Array
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Convention II
Medium5
Heap, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Japan Sinks
Medium5
Sorting, Union-find+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Where is the Boundary
Medium5
Prefix sum, Array+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Surface Area of Cubes
Medium5
Hash map, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Formula Not Exceeding N
Medium5
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Siblings
Medium5
Hash map, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Junior
Medium5
Hash map, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
So You Like Your Food Hot?
Medium5
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Punctilious Cruciverbalist
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
A Random Problem
Medium5
String, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Root Game
Medium5
Game theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Nim Game 3
Medium5
Game theory, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Uukjeo
Medium5
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bomberman 2
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
String Guessing
Medium5
String, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Array Rotation 1
Medium5
Matrix, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Rotating an Array 2
Medium5
Matrix, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Two Dots
Medium5
DFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rotating an Array 3
Medium5
Implementation, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Divide by 3, Multiply by 2
Medium5
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Two Stickers
Medium5
Implementation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
BFS Special Judge
Medium5
BFS, Tree+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Escaping the Moving Maze
Medium5
BFS, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Segments and Queries
Medium5
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Restore the Array
Medium5
Matrix, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Value of Array B
Medium5
Array, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Level Hamburger
Medium5
Recursion, Divide and conquer+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Rocket Powered Hovercraft
Medium5
Geometry, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Pretty Average Primes
Medium5
Number theory, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Icy Perimeter
Medium5
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Mountain View
Medium5
Geometry, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sleepy Cow Sorting
Medium5
Greedy, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Great Revegetation (Bronze)
Medium5
Graph, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Measuring Traffic
Medium5
Intervals, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Pipe Move 2
Medium5
Dynamic programming, Implementation+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Placing Two Crosses
Medium5
Brute force, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Escape the Maze
Medium5
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Subsequence with the Largest Maximum-Minimum Difference
Medium5
Two pointers, Array+2
No attempts yet
Time limit
0.5s
Memory limit
256 MB
Judgeable
Contest
Medium5
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Operations
Medium5
Segment tree, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Gahui's Remainder Sequence Game (Small)
Medium5
Stack, Array+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Fence Planning
Medium5
Union-find, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bucket Brigade
Medium5
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Game of Death
Medium5
Graph, Simulation+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Cowburger Kitchen Worker
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Bowling Score Calculation
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Largest Sum Decreasing Subsequence
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Drug Investigation Unit
Medium5
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Heights
Medium5
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Strength Contest
Medium5
Prefix sum, Array+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Making the Number N
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Dark Tunnel
Medium5
Binary search, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Being a Celebrity Is Hard
Medium5
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
League of Legends (Large)
Medium5
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Tribal War
Medium5
Combinatorics, Math+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Carpool Matching
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
⚾
Medium5
Brute force, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Crazy_aRcade_Good
Medium5
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Next Greater Element
Medium5
Stack, Array+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Frequency-Greater Next Element
Medium5
Stack, Hash map+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Stars Falling from the Sky: 1, 2, ..., R-L+1 of Them
Medium5
Prefix sum, Array+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Segment Intersection 1
Medium5
Geometry, Math+2
No attempts yet
Time limit
0.25s
Memory limit
512 MB
Judgeable
Backdoor
Medium5
Shortest path, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
FLEX
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sum of Divisors
Medium5
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Rotate Array 5
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Course Basket
Medium5
Implementation, Simulation+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Go Stone Jump
Medium5
Backtracking, Matrix+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Promoting a Club
Medium5
Tree, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Brazilian Popcorn Marathon
Medium5
Binary search, Greedy+2
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Bracket Sequence
Medium5
Stack, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Crosswords
Medium5
String, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Strings
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Analogue Cluster
Medium5
Graph, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Code Word
Medium5
Dynamic programming, Matrix+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Summer Trip
Medium5
String, Two pointers+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Palindrome
Medium5
String, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Four Squares
Medium5
Dynamic programming, Math+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Rotate
Medium5
Matrix, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Efficient Exchange
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Find my Family
Medium5
Array, Prefix sum+2
No attempts yet
Time limit
7s
Memory limit
512 MB
Judgeable
Historic Exhibition
Medium5
Graph, Binary search+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Ballpark Estimate
Medium5
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Screamers in the Storm
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Zoo
Medium5
Graph, BFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Snail List
Medium5
Linked list, Array+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
String Currency
Medium5
Greedy, Implementation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Jinsu's Daily Routine
Medium5
Greedy, String+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Save the Princess!
Medium5
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
What Does UNIST Stand For?
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Course Selection
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Retribution!
Medium5
Greedy, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Musical Chairs
Medium5
Simulation, Queue+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Fantasy Draft
Medium5
Simulation, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
American TourFind the shortest walk from node 1 to node N that passes through node 2, where no road may be repeated but nodes may be revisited.	Medium5	GraphShortest path+1	No attempts yet	1s	256 MB	Judgeable
Structure of Balanced NetworksGiven a complete signed graph where every triad is balanced, answer queries about the sign of the edge between two nodes.	Medium5	GraphMath+2	No attempts yet	5s	16 MB	Judgeable
MagnusDelete any letters from a length-N uppercase word so the kept letters contain as many disjoint subsequences "HONI" as possible, and print that maximum.	Medium5	GreedyString+1	No attempts yet	1s	512 MB	Judgeable
Sajam (Christmas Fair)Given an N by N light grid, decide whether at most K single-cell toggles plus row and column toggles can turn every light off.	Medium5	MatrixBit manipulation+1	No attempts yet	5s	512 MB	Judgeable
Fine DiningFor each pasture, decide whether a cow can detour through one haybale on its way to the barn with extra time at most the hay's yumminess.	Medium5	Shortest pathGraph+1	No attempts yet	2s	512 MB	Judgeable
TeamworkPartition cows in a row into blocks of at most K so each block contributes its maximum times block size; maximize the sum.	Medium5	Dynamic programmingArray	No attempts yet	2s	512 MB	Judgeable
Convention IISimulate a single-server queue where queued cows are served by strict priority instead of arrival order, and find the largest start time minus arrival time.	Medium5	HeapSimulation+1	No attempts yet	2s	512 MB	Judgeable
Japan SinksRaise the sea level through the section heights and track how maximal runs of above-level sections merge; report the largest island count seen.	Medium5	SortingUnion-find+2	No attempts yet	2s	512 MB	Judgeable
Where is the BoundaryGiven m binary strings of length n, cut the line between two prefectures and label each side east or west to minimize mismatches. Report the two prefectures meeting at the best cut, choosing the westernmost one on ties.	Medium5	Prefix sumArray+2	No attempts yet	5s	512 MB	Judgeable
Surface Area of CubesGiven an A x B x C block of unit cubes with N cubes removed (including interior ones), compute the total surface area including surfaces of interior cavities.	Medium5	Hash mapMath+2	No attempts yet	5s	512 MB	Judgeable
Formula Not Exceeding NGiven N and a string of digits and plus signs, change the fewest characters so it becomes a valid formula with value at most N, or report -1.	Medium5	Dynamic programmingString	No attempts yet	2s	512 MB	Judgeable
SiblingsGiven each woman's mother as an index, count pairs of women who share the same mother across several data sets.	Medium5	Hash mapSorting+1	No attempts yet	2s	512 MB	Judgeable
JuniorGiven names in birth order with optional junior or iii suffixes, count people who have no earlier possible parent under the naming rules, which is the number of families.	Medium5	Hash mapString+1	No attempts yet	2s	512 MB	Judgeable
So You Like Your Food Hot?Given monthly profit and per-item profits for pita and pizza, find all nonnegative integer pairs whose profit equals the total and list them by pita count, or none.	Medium5	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
The Punctilious CruciverbalistGiven a partly filled crossword grid, print the order in which the unsolved clues are solved when the solver always picks the highest-ranked clue.	Medium5	SimulationImplementation+1	No attempts yet	2s	512 MB	Judgeable
A Random ProblemGiven p random digits, find a triple correlation a(n)b(m)c that satisfies all three rules and occurs at least ceil(p/40)+1 times, or report random sequence.	Medium5	StringBrute force+1	No attempts yet	2s	512 MB	Judgeable
Root GameFor each N, decide who wins the subtraction game where a move subtracts any perfect square from a running total and taking the last square wins.	Medium5	Game theoryDynamic programming+2	No attempts yet	1s	512 MB	Judgeable
Nim Game 3Given Nim pile sizes, count how many first moves (choosing a pile and removing stones) leave the opponent in a losing position.	Medium5	Game theoryBit manipulation+2	No attempts yet	1s	512 MB	Judgeable
UukjeoGiven N word lengths, build binary words of those lengths where no word is a prefix of another, or report -1 if it is impossible.	Medium5	GreedySorting+1	No attempts yet	1s	512 MB	Judgeable
Bomberman 2Simulate Bomberman's bomb placement and explosion cycles on a grid and print the state after N seconds, handling N up to 10^9.	Medium5	SimulationImplementation+2	No attempts yet	2s	512 MB	Judgeable
String GuessingGiven all 2N-2 prefixes and suffixes of a hidden string, recover the string and label each input line as prefix or suffix in order.	Medium5	StringHash map+2	No attempts yet	2s	512 MB	Judgeable
Array Rotation 1Rotate each concentric ring of an N by M matrix counterclockwise R times, then print the resulting matrix.	Medium5	MatrixSimulation+2	No attempts yet	1s	512 MB	Judgeable
Rotating an Array 2Rotate each concentric layer of an N by M matrix one cell counterclockwise, R times, and print the final matrix.	Medium5	MatrixSimulation+2	No attempts yet	1s	512 MB	Judgeable
Two DotsGiven a grid of colored dots, decide whether any cycle of four or more same-colored dots exists, where consecutive dots touch by an edge.	Medium5	DFSGraph+2	No attempts yet	2s	512 MB	Judgeable
Rotating an Array 3Apply a sequence of up to 1000 operations (vertical flip, horizontal flip, quarter rotations, and quadrant swaps) to an N by M array and print the final arrangement.	Medium5	ImplementationSimulation+2	No attempts yet	2s	512 MB	Judgeable
Divide by 3, Multiply by 2Given a shuffled copy B of the sequence produced by a divide-by-3, multiply-by-2 game, reconstruct the original order A.	Medium5	GraphDFS+2	No attempts yet	2s	512 MB	Judgeable
Two StickersGiven an H by W grid and N rectangles that may rotate, place two non-overlapping rectangles inside and maximize their total area.	Medium5	ImplementationBrute force+2	No attempts yet	2s	512 MB	Judgeable
BFS Special JudgeGiven a tree and a permutation of its vertices, decide whether the permutation can be produced by a BFS traversal starting from vertex 1.	Medium5	BFSTree+2	No attempts yet	2s	512 MB	Judgeable
Escaping the Moving MazeAn 8x8 board with walls that shift down one row each second; decide if a character moving first each second can reach the top-right cell.	Medium5	BFSSimulation+2	No attempts yet	2s	512 MB	Judgeable
Segments and QueriesProcess up to 100 queries that add intervals of strictly increasing length and ask whether two added intervals are connected by the overlap-based move relation.	Medium5	GraphUnion-find+2	No attempts yet	1s	512 MB	Judgeable
Restore the ArrayRecover grid A from grid B, where B is built by overlapping A with A shifted down X and right Y so overlapping cells are summed.	Medium5	MatrixSimulation+2	No attempts yet	2s	512 MB	Judgeable
Value of Array BSwap at most one pair of rows or columns in an N by M grid to maximize the sum of all 2 by 2 block sums.	Medium5	ArrayGreedy+2	No attempts yet	2s	512 MB	Judgeable
Level HamburgerA level-N burger is defined recursively from buns and patties; count how many patties lie in the bottom X layers.	Medium5	RecursionDivide and conquer+2	No attempts yet	0.5s	512 MB	Judgeable
Rocket Powered HovercraftGiven a target (x, y), speed v, and turn rate w, find the minimum time for a hovercraft starting at the origin facing +X to reach the target.	Medium5	GeometryMath	No attempts yet	2s	512 MB	Judgeable
Pretty Average PrimesFor each N, print two primes whose average is N, which means finding a prime pair that sums to 2N.	Medium5	Number theoryBrute force+2	No attempts yet	1s	512 MB	Judgeable
Icy PerimeterFind the connected component of '#' cells with the largest area, breaking ties by smallest perimeter, where perimeter counts all edges touching non-component cells including holes.	Medium5	GraphDFS+2	No attempts yet	2s	512 MB	Judgeable
Mountain ViewCount how many mountain peaks are not covered by any other 45-degree right-triangle mountain with its base on the x-axis.	Medium5	GeometrySorting+2	No attempts yet	2s	512 MB	Judgeable
Sleepy Cow SortingGiven a permutation of 1..N, repeatedly move the front cow any number of paces back; find the minimum number of steps to reach sorted order.	Medium5	GreedyArray+2	No attempts yet	2s	512 MB	Judgeable
The Great Revegetation (Bronze)Assign each of N pastures one of 4 grass types so that every listed pair differs, choosing the lexicographically smallest N-digit answer.	Medium5	GraphGreedy+2	No attempts yet	2s	512 MB	Judgeable
Measuring TrafficGiven sensor readings for each mile as inflow, outflow, or highway flow ranges, find the tightest possible interval for the flow before mile 1 and after mile N.	Medium5	IntervalsSimulation+2	No attempts yet	2s	512 MB	Judgeable
Pipe Move 2Count the ways to push a 2-cell pipe (horizontal, vertical, or diagonal) across an N by N grid so its end reaches (N, N), keeping all covered cells empty.	Medium5	Dynamic programmingImplementation+2	No attempts yet	0.5s	512 MB	Judgeable
Placing Two CrossesGiven a small grid of '.' and '#', place two non-overlapping crosses made of '#' cells and maximize the product of their areas.	Medium5	Brute forceImplementation+2	No attempts yet	2s	512 MB	Judgeable
Escape the MazeEach cell holds a direction to the next cell; count how many starting cells eventually leave the N by M grid.	Medium5	GraphDFS+2	No attempts yet	1s	512 MB	Judgeable
Subsequence with the Largest Maximum-Minimum DifferenceGiven a sequence, find the shortest contiguous segment whose max minus min equals the largest such difference over all segments.	Medium5	Two pointersArray+2	No attempts yet	0.5s	256 MB	Judgeable
ContestGiven N intervals with start time, end time, and prize money, choose non-overlapping contests (end must not touch the next start) to maximize total prize.	Medium5	Dynamic programmingSorting+2	No attempts yet	1s	256 MB	Judgeable
OperationsMaintain a sparse integer array under point add, point reset, and range sum queries, printing the whole-array sum after each update.	Medium5	Segment treePrefix sum+2	No attempts yet	2s	512 MB	Judgeable
Gahui's Remainder Sequence Game (Small)Maintain a sequence under push and pop from the back, and for each type-3 query report the shortest suffix whose values cover every residue 0 to mod-1, or -1 if impossible.	Medium5	StackArray+1	No attempts yet	1s	256 MB	Judgeable
Fence PlanningConnect cows into groups given moo pairs, then find the axis-aligned rectangle of smallest perimeter that fully contains one group.	Medium5	Union-findGraph+2	No attempts yet	2s	512 MB	Judgeable
Bucket BrigadeOn a fixed 10x10 grid with one barn, one lake, and one blocked rock, find the fewest empty squares to occupy so a chain of cows links the lake to the barn.	Medium5	BFSGraph+2	No attempts yet	2s	512 MB	Judgeable
Game of DeathGiven a fixed pointing map for N people, find the smallest positive M so that starting at person 0 and following M pointers ends on person K.	Medium5	GraphSimulation+2	No attempts yet	2s	256 MB	Judgeable
Cowburger Kitchen WorkerWith M cheeseburgers and K fries available, pick the largest subset of orders, each requiring some of each item, that fits within both limits.	Medium5	Dynamic programmingGreedy+2	No attempts yet	3s	512 MB	Judgeable
Bowling Score CalculationGiven a string describing each ball's result in a 10-frame bowling game (S for strike, P for spare, - for zero, digits otherwise), compute the final score using strike and spare bonus rules.	Medium5	SimulationImplementation+2	No attempts yet	1s	256 MB	Judgeable
Largest Sum Decreasing SubsequenceGiven a sequence, find a strictly decreasing subsequence with the maximum possible sum and print that sum.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	256 MB	Judgeable
Drug Investigation UnitGiven a directed supply graph and a set of arrested suppliers, count how many remaining suppliers still receive drugs from some origin.	Medium5	GraphDFS+2	No attempts yet	1s	256 MB	Judgeable
HeightsGiven the three heights of a triangle, compute its area within an absolute error of 1e-5.	Medium5	MathGeometry+2	No attempts yet	1s	256 MB	Judgeable
Strength ContestFor each split of a line of fighters into a left and right team, the max of each side fights; count which side wins more splits, or report a tie.	Medium5	Prefix sumArray+2	No attempts yet	1s	256 MB	Judgeable
Making the Number NCount how many digit-by-digit sequences build the number N when each new digit is attached to the left or right end.	Medium5	Dynamic programmingString+2	No attempts yet	1s	256 MB	Judgeable
Dark TunnelStreetlights sit at fixed positions along a tunnel from 0 to N, each lighting H units left and right; find the smallest integer H that covers the whole road.	Medium5	Binary searchGreedy+2	No attempts yet	1s	256 MB	Judgeable
Being a Celebrity Is HardGiven a weighted undirected graph and two starting nodes, pick a meeting node minimizing the sum of both shortest distances and breaking ties by Jiheon's distance then index.	Medium5	Shortest pathGraph+1	No attempts yet	1s	256 MB	Judgeable
League of Legends (Large)Count the sequences of skills A (1 second) and B (M seconds) that fill exactly N seconds with no idle time, modulo 1e9+7.	Medium5	Dynamic programmingCombinatorics+1	No attempts yet	3s	256 MB	Judgeable
Tribal WarGiven N tribes where listed pairs are allied and all other pairs are hostile, count the number of triples that are all allied or all hostile.	Medium5	CombinatoricsMath+2	No attempts yet	3s	512 MB	Judgeable
Carpool MatchingEach passenger has a destination point and each driver accepts a closed interval of destinations; match the maximum number of passenger-driver pairs.	Medium5	GreedySorting+2	No attempts yet	3s	512 MB	Judgeable
⚾Given each of 9 players' predetermined results over N innings, choose a batting order with player 1 batting 4th to maximize total runs scored.	Medium5	Brute forceSimulation+2	No attempts yet	1s	512 MB	Judgeable
Crazy_aRcade_GoodGiven a 10x10 board with bombs and a start cell, find the fewest moves to reach a cell not sharing a row or column with any bomb.	Medium5	BFSGraph+2	No attempts yet	1s	256 MB	Judgeable
Next Greater ElementFor each element of a sequence, output the nearest greater value to its right, or -1 if none exists.	Medium5	StackArray+2	No attempts yet	1s	512 MB	Judgeable
Frequency-Greater Next ElementFor each position, find the nearest value to its right whose total frequency in the array exceeds the frequency of the current element, or -1 if none exists.	Medium5	StackHash map+2	No attempts yet	1s	512 MB	Judgeable
Stars Falling from the Sky: 1, 2, ..., R-L+1 of ThemMaintain an array where a range update adds 1,2,...,R-L+1 to positions L..R, and point queries ask the current total at one index.	Medium5	Prefix sumArray+2	No attempts yet	1s	512 MB	Judgeable
Segment Intersection 1Given the integer endpoints of two segments, decide whether the segments intersect, using orientation tests with no three input points collinear.	Medium5	GeometryMath+2	No attempts yet	0.25s	512 MB	Judgeable
BackdoorFind the shortest travel time from junction 0 to junction N-1 in an undirected weighted graph, where every intermediate junction marked visible is blocked and only the Nexus may be entered.	Medium5	Shortest pathGraph+2	No attempts yet	2s	512 MB	Judgeable
FLEXDistribute M extra ten-thousand-won units among N days to minimize the sum of squared drops between consecutive daily spends.	Medium5	Dynamic programmingGreedy+2	No attempts yet	2s	512 MB	Judgeable
Sum of DivisorsGiven N up to 10^6 and 10^5 test cases, compute g(N), the sum of the divisor sums f(y) for all y from 1 to N.	Medium5	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
Rotate Array 5Apply up to 2 million flip, rotate, and quadrant-shift operations to an N by M grid and print the final grid.	Medium5	SimulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
Course BasketGiven seat caps and two rounds of course requests per student, decide which courses each student gets, breaking ties by student order within each round.	Medium5	ImplementationSimulation+2	No attempts yet	2s	256 MB	Judgeable
Go Stone JumpGiven an N by N board of walls, empty cells, and stones, decide whether repeated jumps over adjacent stones can leave exactly one stone.	Medium5	BacktrackingMatrix+1	No attempts yet	1s	256 MB	Judgeable
Promoting a ClubGiven a forest, choose the fewest vertices so that every vertex is either chosen or adjacent to a chosen one (minimum dominating set on a forest).	Medium5	TreeDynamic programming+2	No attempts yet	2s	256 MB	Judgeable
Brazilian Popcorn MarathonSplit a row of popcorn bags into at most C contiguous segments, minimizing the maximum segment sum given each competitor eats at most T per second.	Medium5	Binary searchGreedy+2	No attempts yet	1.5s	512 MB	Judgeable
Bracket SequenceEvaluate a bracket sequence where nesting alternates between addition and multiplication, printing the result modulo 10^9+7.	Medium5	StackImplementation+2	No attempts yet	2s	512 MB	Judgeable
CrosswordsCount the grids with N rows and M columns where every column spells a word from list A and every row spells a word from list B.	Medium5	StringHash map+1	No attempts yet	2s	512 MB	Judgeable
StringsBuild strings by concatenating earlier strings or slicing a substring, then output the sum of ASCII codes of the final string modulo 1e9+7, without materializing the possibly huge string.	Medium5	Dynamic programmingString+2	No attempts yet	2s	512 MB	Judgeable
Analogue ClusterGiven n vertices with widths and c edges, recolor the fewest vertices so every edge joins equal widths, per connected component.	Medium5	GraphGreedy+2	No attempts yet	1s	512 MB	Judgeable
Code WordCount length-l digit sequences on an r by c grid where no two consecutive presses are orthogonally or diagonally adjacent, mod 1e9+7.	Medium5	Dynamic programmingMatrix+2	No attempts yet	1s	512 MB	Judgeable
Summer TripGiven a string of event types, count contiguous substrings of length at least two whose first and last characters are distinct and each appears only once in the substring.	Medium5	StringTwo pointers+2	No attempts yet	3s	1024 MB	Judgeable
PalindromeFor each string, print 0 if it is a palindrome, 1 if deleting one character makes it a palindrome, or 2 otherwise.	Medium5	StringTwo pointers+2	No attempts yet	1s	512 MB	Judgeable
Four SquaresGiven n up to 50,000, print the minimum number of perfect squares whose sum equals n.	Medium5	Dynamic programmingMath+2	No attempts yet	0.5s	512 MB	Judgeable
RotateGiven an N by N letter board and Q square regions, print the board after rotating each region 90 degrees counterclockwise in order.	Medium5	MatrixSimulation+1	No attempts yet	2s	512 MB	Judgeable
Efficient ExchangeGiven a payment amount, minimize the total number of power-of-10 coins exchanged in both directions, allowing both sides to give change.	Medium5	Dynamic programmingGreedy+2	No attempts yet	3s	512 MB	Judgeable
Find my FamilyFor each photo, decide whether some arrangement lets Alice (taller than you) stand left of you and Bob (taller than both) stand right of you.	Medium5	ArrayPrefix sum+2	No attempts yet	7s	512 MB	Judgeable
Historic ExhibitionAssign each vase to a distinct pedestal whose top or bottom diameter matches the vase base, flipping pedestals as needed or reporting impossible.	Medium5	GraphBinary search+2	No attempts yet	1s	512 MB	Judgeable
Ballpark EstimateGiven n up to 1e18, print the closest number that has a single non-zero digit, breaking ties toward the larger value.	Medium5	MathImplementation+2	No attempts yet	2s	512 MB	Judgeable
Screamers in the StormSimulate T turns of wolves and sheep moving, eating, and starving on a small grid, and print the final tile states.	Medium5	SimulationImplementation+2	No attempts yet	2s	512 MB	Judgeable
ZooGiven an R by C grid of T, B, and * footprints, find the minimum number of animals that could have left them.	Medium5	GraphBFS+1	No attempts yet	2s	512 MB	Judgeable
Snail ListA linked list has a tail node N pointing back to node V, forming one cycle. For each query K, report the value stored in the node reached after moving K steps from node 1.	Medium5	Linked listArray+2	No attempts yet	1s	256 MB	Judgeable
String CurrencyFind the lexicographically smallest string of length N over A-Z, where letter values 1 to 26 sum to exactly X, or print ! if impossible.	Medium5	GreedyImplementation+1	No attempts yet	1s	256 MB	Judgeable
Jinsu's Daily RoutineGiven N and a binary string B with '?' wildcards, and A = 2^N - 1 (all ones), find the maximum and minimum bit-lengths of A*B over all replacements of the '?'.	Medium5	GreedyString+2	No attempts yet	2s	256 MB	Judgeable
Save the Princess!Given an N by M grid with walls and one sword cell, find the minimum steps from (1,1) to (N,M) within T, where the sword lets the hero pass through walls afterward.	Medium5	BFSGraph+2	No attempts yet	1s	256 MB	Judgeable
What Does UNIST Stand For?Count ways to pick a prefix of each of N words so the concatenation spells UNIST, modulo 1e9+7.	Medium5	Dynamic programmingString+2	No attempts yet	1s	512 MB	Judgeable
Course SelectionChoose courses with given importance and study time so total time stays within N and total importance is maximized.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	512 MB	Judgeable
Retribution!Assign tar repositories and feather storehouses to judges one at a time by repeatedly taking the closest remaining pair, breaking ties by lowest index, and report the total distance.	Medium5	GreedyImplementation+2	No attempts yet	2s	512 MB	Judgeable
Musical ChairsSimulate the Josephus elimination where each eliminated person's own number k sets the next count length, and print the last survivor.	Medium5	SimulationQueue+2	No attempts yet	1s	512 MB	Judgeable
Fantasy DraftSimulate a snake-free fantasy draft where each owner repeatedly takes the best available player on their own preference list, falling back to the previous year's ranking.	Medium5	SimulationHash map+2	No attempts yet	2s	512 MB	Judgeable