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Total results3,613 problems

Slicing Trees and Checking Paths
Medium6
Tree, DFS
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Cheeseburger
Medium6
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Succession
Medium6
Dynamic programming, Tree+1
No attempts yet
Time limit
12s
Memory limit
1024 MB
Judgeable
Tree and XOR
Medium6
Tree, DFS+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Trucks
Medium6
Minimum spanning tree, Union-find+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cleanup
Medium6
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Easter Eggs
Medium6
Graph, Tree+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Baked Goods
Medium6
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Daegu Science High School Bet
Medium6
Sorting, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cookie-Loving Chunbae
Medium6
Dynamic programming, Segment tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Meeting Point
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Exam Study Planning
Medium6
Dynamic programming, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Skewers
Medium6
Graph, Matrix
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fast Forward
Medium6
Prefix sum, Greedy+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Fragmentation
Medium6
Number theory, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Younger Sibling of a Right Triangle
Medium6
Geometry, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Data Center Maintenance
Medium6
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Houses in Berland
Medium6
Graph, BFS
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Honest Bureaucracy
Medium6
Binary search, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Escape Plan
Medium6
BFS, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
The Evil League of Evil
Medium6
Greedy, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fast Waiting
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Kuglice (Christmas Ornaments)
Medium6
Dynamic programming, Game theory+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Someday, It Would Be Nice to Get Sorted
Medium6
Topological sort, Greedy+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Inverted Triangles
Medium6
Sorting, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Collection
Medium6
Segment tree, Prefix sum
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Replace Sort
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Unique lake
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Milano C.le
Medium6
Dynamic programming, Binary search
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Very Important Edge
Medium6
Minimum spanning tree, Graph+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Stationing
Medium6
Dynamic programming, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Room Temperature
Medium6
Binary search, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Ants
Medium6
Prefix sum, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Split the GSHS 3
Medium6
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Best Friends
Medium6
Geometry, Hash map+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Closet
Medium6
Binary search, Dynamic programming+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Lecture Rooms
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Function Loop Detection
Medium6
Array, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
I Am a Polar Bear
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Passport Stamps
Medium6
Greedy, Heap
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Collusion on Two Wheels
Medium6
Binary search, Graph+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Restore a Binary Search Tree
Medium6
Sorting, Divide and conquer+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Cheater Search
Medium6
Two pointers, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sequence and Frog
Medium6
Graph, Shortest path
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Card Flipping 1
Medium6
Segment tree, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Simple Tree Decomposition Problem
Medium6
Tree, Dynamic programming
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Headline Heat
Medium6
String matching, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Keeping the Tree Healthy
Medium6
Tree, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Awkward Auction
Medium6
Dynamic programming, Game theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Annoying Alliterations
Medium6
Trie, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Gridlock
Medium6
Topological sort, Greedy+1
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Filling the Tree
Medium6
Greedy, Tree+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dial Roulette
Medium6
Array, Sliding window+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Priority Queue and Simulation
Medium6
Sorting, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Perfect City Design
Medium6
Graph, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Repetitive Routes
Medium6
Intervals, Prefix sum+1
No attempts yet
Time limit
8s
Memory limit
2048 MB
Judgeable
Diagonal Flipping
Medium6
Union-find, Graph+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
New Megacity
Medium6
Minimum spanning tree, Union-find+2
No attempts yet
Time limit
2.5s
Memory limit
2048 MB
Judgeable
Cards Flipping
Medium6
Union-find, Graph
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Optimized Cheating
Medium6
BFS, Hash map+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Black and White Landscaper
Medium6
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Flowing Fountain
Medium6
Stack, Union-find+1
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
Bountiful Tree
Medium6
Tree, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Partial Sums of a Triangle
Medium6
Prefix sum, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Packing Luggage
Medium6
Greedy, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Tree Reading
Medium6
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Omnes Viae Yokohamam Ducunt?
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Stock Market
Medium6
Prefix sum, Math+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
The Guardian of Balance
Medium6
Tree, Dynamic programming+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Colorful Intervals
Medium6
Sliding window, Array+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Hoditi Hribima
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Strong Jovsi
Medium6
Prefix sum, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Highways of the Future
Medium6
Graph, DFS+1
No attempts yet
Time limit
6s
Memory limit
2048 MB
Judgeable
Alien Journey
Medium6
Shortest path, Sliding window+1
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
Balloon Party
Medium6
Matrix, Heap+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Generate Optimal Key
Medium6
Greedy, Heap+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Star Showdown
Medium7
Greedy, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Moving Pieces
Medium7
BFS, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Coin Board Game
Medium7
Dynamic programming, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Risk
Medium7
Graph
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Sentries
Medium7
Greedy, Intervals+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Coloring the Table
Medium7
Math, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Mobile
Medium7
Tree, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Party Location
Medium7
Geometry, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shortest Flight Path
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Stacking Bowls
Medium7
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Faucet Flow
Medium7
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Laser Tag
Medium7
Geometry, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cell Towers
Medium7
Geometry, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Transmitters
Medium7
Geometry, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Safety in Alchemy
Medium7
Graph, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Apply a Cold Compress
Medium7
Recursion, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Clickomania
Medium7
Dynamic programming, Intervals+1
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Planks
Medium7
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hop — Don't Walk!
Medium7
BFS, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Discrete Speed
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
8s
Memory limit
128 MB
Judgeable
Cards
Medium7
Graph, Number theory+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Traveling by Stagecoach
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Cookie Selection
Medium7
Heap, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Allergy Test
Medium7
Combinatorics, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Slicing Trees and Checking PathsGiven a tree, for each query remove the edges on the path from a to b and report whether c and d are still connected.	Medium6	TreeDFS	No attempts yet	4s	1024 MB	Judgeable
CheeseburgerEach farm supplies only the chain stores nearest to it, and each store pays the cheapest price among farms that can supply it. Output that price per store, or -1.	Medium6	Shortest pathGraph	No attempts yet	1s	1024 MB	Judgeable
SuccessionPick exactly K areas that form a connected subtree of the road tree to maximize total value, then count the ways to achieve that maximum modulo 1000000007.	Medium6	Dynamic programmingTree+1	No attempts yet	12s	1024 MB	Judgeable
Tree and XORFor each root r, find the minimum cost to make all vertex values equal, where XOR-ing a subtree by c costs its size times c.	Medium6	TreeDFS+1	No attempts yet	3s	1024 MB	Judgeable
TrucksGiven roads with travel times, answer each query by checking whether a driver can get from city a to city b when every road on the route fits within the rest limit p.	Medium6	Minimum spanning treeUnion-find+1	No attempts yet	1s	1024 MB	Judgeable
CleanupGroup the sorted debris sites into piles, paying T per pile plus the bulldozing cost to each pile's weighted median, and find the minimum total time.	Medium6	Dynamic programmingPrefix sum+1	No attempts yet	8s	1024 MB	Judgeable
Easter EggsEach child passes eggs along fixed wish edges, and every child is wanted by at most one other. Find the most children who can get an egg when the Bunny starts with M eggs.	Medium6	GraphTree+2	No attempts yet	1s	1024 MB	Judgeable
Baked GoodsGiven a budget S and two cupcake types, each with an ingredient cost and a profit, find the maximum total profit from an affordable whole-number mix of the two.	Medium6	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
Daegu Science High School BetIan reorders his scores to maximize his total winnings against Yehwan's fixed scores, where a win pays 100, a tie pays 20, and a loss costs 50.	Medium6	SortingGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Cookie-Loving ChunbaeEach cookie has a position, a cost, and a free-range radius, and the task asks for the cheapest set of purchases whose ranges together cover all K cookies.	Medium6	Dynamic programmingSegment tree+1	No attempts yet	1s	1024 MB	Judgeable
Meeting PointGiven a weighted road graph, list every crossroad X where the shortest distance from P to X is twice the P-to-G distance and every shortest path to X passes through G.	Medium6	Shortest pathGraph+1	No attempts yet	0.5s	1024 MB	Judgeable
Exam Study PlanningGiven exams with start, early-exit, and full end times plus study needs, find the most exams you can pass by studying in free time before each exam starts.	Medium6	Dynamic programmingGreedy	No attempts yet	1s	1024 MB	Judgeable
SkewersGiven a grid of meat, scallion, and mushroom cells, find the most skewers that each take one adjacent meat and scallion in a line with a mushroom at one end.	Medium6	GraphMatrix	No attempts yet	1s	1024 MB	Judgeable
Fast ForwardFor each start song in a circular playlist, count the ads that play when an ad can only follow a song and at least c seconds must pass between ads.	Medium6	Prefix sumGreedy+2	No attempts yet	2s	1024 MB	Judgeable
FragmentationFor each query range of machine characteristics, decide whether the product of those values is divisible by the number of laboratories k.	Medium6	Number theoryPrefix sum+1	No attempts yet	2s	1024 MB	Judgeable
Younger Sibling of a Right TriangleFor each query (a, b), count the black points inside or on the boundary of the triangle with vertices (0, 0), (a, b), and (a, 0).	Medium6	GeometrySorting+1	No attempts yet	3s	1024 MB	Judgeable
Data Center MaintenanceGiven data center maintenance hours and client pairs, find the fewest data centers to shift one hour later so every client keeps one copy reachable.	Medium6	GraphDFS+1	No attempts yet	1s	1024 MB	Judgeable
Houses in BerlandFind the shortest distance between two residential houses with different resident counts in a connected graph of crossroads and roads.	Medium6	GraphBFS	No attempts yet	2s	1024 MB	Judgeable
Honest BureaucracySplit at most K coins so the favorite with the smallest weight gets as many as possible, with strictly larger weights receiving strictly more.	Medium6	Binary searchSorting+1	No attempts yet	1s	1024 MB	Judgeable
Escape PlanFor each room, find the nearest exit left open after the K nearest exits close, breaking distance ties by the smaller room number.	Medium6	BFSGraph+1	No attempts yet	2s	1024 MB	Judgeable
The Evil League of EvilReplace each ? with ( or ) so the longest correct bracket subsequence of the string is as long as possible, then print the resulting string.	Medium6	GreedyString+1	No attempts yet	1s	1024 MB	Judgeable
Fast WaitingFind the minimum time from stop 1 to stop N when Jaewon can make up to K routes depart immediately instead of waiting for their next scheduled bus.	Medium6	GraphShortest path+1	No attempts yet	2s	1024 MB	Judgeable
Kuglice (Christmas Ornaments)Two players alternately draw ornaments from either end of a box, scoring a point for each color drawn for the first time. Find both final scores under optimal play.	Medium6	Dynamic programmingGame theory+1	No attempts yet	0.5s	1024 MB	Judgeable
Someday, It Would Be Nice to Get SortedAdjacent coprime elements may be swapped any number of times; output the lexicographically smallest sequence that can be reached.	Medium6	Topological sortGreedy+1	No attempts yet	2s	1024 MB	Judgeable
Inverted TrianglesGiven N points, find the sum of doubled areas of all inverted triangles, where the middle-x point has the lowest y, modulo 1000000007.	Medium6	SortingPrefix sum+1	No attempts yet	2s	1024 MB	Judgeable
CollectionGiven up to 10 test cases, add x coins to each type in a range, clear all coins in a range, and print the total value of the collection on each query.	Medium6	Segment treePrefix sum	No attempts yet	5s	1024 MB	Judgeable
Replace SortGiven an array A and a set B of distinct values, find the fewest elements of A to replace with values from B so that A becomes sorted, or report -1.	Medium6	GreedySorting+2	No attempts yet	3s	1024 MB	Judgeable
Unique lakeFind the length of the longest chain of points where each next point is strictly greater in both x and y, and count such longest chains modulo 1e9+7.	Medium6	Dynamic programmingSorting+1	No attempts yet	1s	1024 MB	Judgeable
Milano C.leGiven arrival and departure orders for n trains, find the fewest platforms so that no train is blocked by one that entered before it.	Medium6	Dynamic programmingBinary search	No attempts yet	1s	1024 MB	Judgeable
Very Important EdgeGiven a weighted connected graph, find the edge whose removal gives the largest minimum spanning tree weight, and print that weight.	Medium6	Minimum spanning treeGraph+1	No attempts yet	3s	2048 MB	Judgeable
StationingPlace troops in regions to maximize the total number of neighboring regions without troops, where each region links to one other region d_i.	Medium6	Dynamic programmingGraph+1	No attempts yet	1s	1024 MB	Judgeable
Room TemperatureChoose an integer room temperature that minimizes the worst officer's distance to their achievable temperatures A_i - kT, with k at least 0.	Medium6	Binary searchSorting+1	No attempts yet	2s	1024 MB	Judgeable
AntsGiven n ants on a line, each facing left or right, count how many times each ant bounces off other ants when they collide and reverse.	Medium6	Prefix sumSimulation	No attempts yet	1s	1024 MB	Judgeable
Split the GSHS 3Given a tree of buildings with student counts, cut two edges to split it into three parts and maximize the product of their student totals.	Medium6	TreeDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Best FriendsProcess queries that toggle base stations on the plane and count the stations forming an acute triangle with (-x,0) and (x,0) for a given x.	Medium6	GeometryHash map+1	No attempts yet	2s	1024 MB	Judgeable
ClosetFind the smallest tolerance x so that removing at most M clothes leaves a sequence that rises then falls, with each adjacent step at most x.	Medium6	Binary searchDynamic programming+1	No attempts yet	5s	1024 MB	Judgeable
Lecture RoomsGiven N lecture room positions on a line and at most K teleports from x=0, find the minimum walking time to visit every room.	Medium6	GreedySorting+1	No attempts yet	1s	1024 MB	Judgeable
Function Loop DetectionFind the segment of distinct function names that repeats consecutively the most times in a call list, then print its length, repeat count, and contents.	Medium6	ArrayHash map+1	No attempts yet	1s	1024 MB	Judgeable
I Am a Polar BearGiven glaciers joined by bridges that collapse at fixed times, find the longest time the bear can stay at glacier 1 and still reach glacier N.	Medium6	GraphShortest path+1	No attempts yet	1.5s	1024 MB	Judgeable
Passport StampsGiven trips that each need c contiguous blank pages, find the first trip an adversarial officer could block in a passport of p pages.	Medium6	GreedyHeap	No attempts yet	1s	2048 MB	Judgeable
Collusion on Two WheelsSplit N customers into two groups to minimize the largest Manhattan distance between any two customers in the same group.	Medium6	Binary searchGraph+2	No attempts yet	1s	1024 MB	Judgeable
Restore a Binary Search TreeGiven each node's value and depth, rebuild a binary search tree from them, or report -1 when no such tree exists.	Medium6	SortingDivide and conquer+1	No attempts yet	2s	1024 MB	Judgeable
Cheater SearchFind a contiguous cheater interval [l, r] so that cheaters' claimed ranges avoid it and every non-cheater's claimed range overlaps it.	Medium6	Two pointersPrefix sum+1	No attempts yet	2s	1024 MB	Judgeable
Sequence and FrogGiven arrays a and b, a frog starts at x, jumps to x-a_x or x+a_x after waiting b_x seconds each step. Find the earliest time it can leave the array for every start.	Medium6	GraphShortest path	No attempts yet	2s	1024 MB	Judgeable
Card Flipping 1Given N cards with fronts p_1 to p_N, flip card j whenever an earlier card's top exceeds its top, then output each card's final top.	Medium6	Segment treeMath	No attempts yet	2s	1024 MB	Judgeable
Simple Tree Decomposition ProblemCount the edge subsets of a tree whose removal leaves every connected component with exactly A or B vertices, modulo 10^9+7.	Medium6	TreeDynamic programming	No attempts yet	3s	1024 MB	Judgeable
Headline HeatGiven university names, rival pairs, and news articles, decide for each article whether some university is mentioned fewer times than one of its rivals.	Medium6	String matchingString+1	No attempts yet	2s	1024 MB	Judgeable
Keeping the Tree HealthyGiven a tree whose nodes are marked 1 (unhealthy) or 0, cut the fewest edges so every connected component has at most K unhealthy nodes, and print that count.	Medium6	TreeDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Awkward AuctionGiven n and bribe b, find the worst-case total cost of bidding to hit a hidden integer value from 1 to n, when each low bid costs b and each bid is paid.	Medium6	Dynamic programmingGame theory	No attempts yet	1s	1024 MB	Judgeable
Annoying AlliterationsGiven n words, find the two words whose combined length is maximized after stripping leading letters from both while their first letters match.	Medium6	TrieString+1	No attempts yet	2s	1024 MB	Judgeable
GridlockGiven a grid of arrow blocks, find an order that slides every block out of the grid in its arrow direction, or report that no such order exists.	Medium6	Topological sortGreedy+1	No attempts yet	6s	1024 MB	Judgeable
Filling the TreeDecide whether the unused sticker numbers can fill a rooted tree so each parent's sticker exceeds its child's, and print one valid filling.	Medium6	GreedyTree+2	No attempts yet	1s	1024 MB	Judgeable
Dial RouletteGiven a circular sequence A of length N, find the maximum sum of numbers passed when the dial is rotated K times.	Medium6	ArraySliding window+1	No attempts yet	1s	1024 MB	Judgeable
Priority Queue and SimulationGiven a priority queue, add A_i to every element, reduce each element modulo K, and print the maximum after each of T queries.	Medium6	SortingSimulation	No attempts yet	1s	1024 MB	Judgeable
Perfect City DesignGiven a graph where each city has exactly one outgoing road, find the fewest road changes needed so every city can reach every other city.	Medium6	GraphGreedy	No attempts yet	1s	1024 MB	Judgeable
Repetitive RoutesSum, over all customers, how many stops during each customer's ride revisit a location already visited on that same ride.	Medium6	IntervalsPrefix sum+1	No attempts yet	8s	2048 MB	Judgeable
Diagonal FlippingGiven a 0/1 grid, find the fewest diagonal flips (both diagonal directions) that turn every cell to 0, or report -1 if impossible.	Medium6	Union-findGraph+1	No attempts yet	1s	2048 MB	Judgeable
New MegacityGiven n cities and m weighted roads, label each road 1 if every minimum spanning tree uses it, 2 if some do but not all, and 3 if none do.	Medium6	Minimum spanning treeUnion-find+2	No attempts yet	2.5s	2048 MB	Judgeable
Cards FlippingEach card has a color on each side and can be flipped. Find the maximum number of distinct colors that can appear on the top sides.	Medium6	Union-findGraph	No attempts yet	1s	2048 MB	Judgeable
Optimized CheatingFind the fewest operations that turn Bob's currency into a value no other memory slot holds, printing the operation indices or -1 if impossible.	Medium6	BFSHash map+1	No attempts yet	1s	2048 MB	Judgeable
Black and White LandscaperGiven a tree with vertices colored white or black, find every root for which each vertex with children takes the majority color of its descendants.	Medium6	TreeDFS+1	No attempts yet	2s	1024 MB	Judgeable
Flowing FountainChampagne poured into a level spills into the first lower level with a larger capacity, and the task is to answer how much each level holds.	Medium6	StackUnion-find+1	No attempts yet	5s	2048 MB	Judgeable
Bountiful TreeGiven a tree, decide whether every node has degree 1 or 3 and all leaves are equally far from the root, then list all valid roots.	Medium6	TreeDFS+1	No attempts yet	1s	1024 MB	Judgeable
Partial Sums of a TriangleGiven a triangular grid of numbers, answer up to 500,000 queries that each ask for the sum of a sub-triangle with apex at (x, y) and height z.	Medium6	Prefix sumArray+1	No attempts yet	1s	1024 MB	Judgeable
Packing LuggagePick K pieces in total, where each extra piece of kind i gains less by A_i than the last, and find the maximum total value.	Medium6	GreedyBinary search+1	No attempts yet	2s	1024 MB	Judgeable
Tree ReadingGiven a tree whose vertices each hold a digit from 1 to 9, sum the numbers read along the path for every ordered pair of vertices, modulo 1,000,000,007.	Medium6	TreeDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Omnes Viae Yokohamam Ducunt?Find a spanning tree rooted at city 1 that minimizes the sum over edges of vulnerability times the significance total of the cities cut off from city 1 by that edge.	Medium6	Shortest pathGraph+1	No attempts yet	3s	2048 MB	Judgeable
Stock MarketGiven a periodic price sequence whose total change is negative, find the lowest price the stock reaches that is at least X, or report -1 if none exists.	Medium6	Prefix sumMath+1	No attempts yet	1s	2048 MB	Judgeable
The Guardian of BalanceGiven a weighted tree, find the vertex whose distances to all vertices have the smallest variance, breaking ties by the smaller vertex number.	Medium6	TreeDynamic programming+1	No attempts yet	1.5s	1024 MB	Judgeable
Colorful IntervalsGiven n painting colors in a line, find two intervals that together contain every color, minimizing the sum of their lengths.	Medium6	Sliding windowArray+1	No attempts yet	1s	2048 MB	Judgeable
Hoditi HribimaMarin and Vedran alternately take edges that strictly lower their own distance to t. Find the longest total length Ivan can force, or -1 if it can go on forever.	Medium6	GraphShortest path+1	No attempts yet	1s	2048 MB	Judgeable
Strong JovsiFind the shortest walk on a line of l bars that picks up and delivers all n packages, with free start and end points.	Medium6	Prefix sumDynamic programming+1	No attempts yet	1s	2048 MB	Judgeable
Highways of the FutureGiven a directed graph of sectors and one-way highways, find the fewest new directed highways needed so every sector can reach every other sector.	Medium6	GraphDFS+1	No attempts yet	6s	2048 MB	Judgeable
Alien JourneyFind the least lift height for an l by l square ship to move from the top-left to the bottom-right corner of a height grid.	Medium6	Shortest pathSliding window+1	No attempts yet	5s	2048 MB	Judgeable
Balloon PartyGiven a grid of ceiling heights, find the maximum volume of helium the tent can hold without any of it spilling over the lowest edge.	Medium6	MatrixHeap+1	No attempts yet	1s	2048 MB	Judgeable
Generate Optimal KeyGiven n binary patterns and m forbidden keys of length L, find the non-forbidden binary key with the smallest total Hamming distance to all patterns.	Medium6	GreedyHeap+1	No attempts yet	2s	2048 MB	Judgeable
Star ShowdownGiven row and column game counts, build the 0/1 matrix with those degrees that is lexicographically smallest row by row, or print -1 if none exists.	Medium7	GreedyGraph+2	No attempts yet	2s	128 MB	Judgeable
Moving PiecesGiven at most 5 pieces on a 5x5 board, find the minimum number of sliding moves so all pieces form one connected component.	Medium7	BFSBrute force+2	No attempts yet	2s	512 MB	Judgeable
Coin Board GameA coin on a grid jumps exactly the digit on its cell in one of four directions; find the maximum number of moves before it leaves the board or hits a hole, or -1 if it can move forever.	Medium7	Dynamic programmingDFS+2	No attempts yet	2s	512 MB	Judgeable
Risknot used	Medium7	Graph	No attempts yet	3s	128 MB	Judgeable
SentriesGiven interval reports saying each range holds no ninja or at least one, find every bush that holds a ninja in all valid placements of exactly K ninjas.	Medium7	GreedyIntervals+2	No attempts yet	1s	256 MB	Judgeable
Coloring the TableCount colorings of an n by m grid, red or blue, where every 2 by 2 block has an odd number of red cells, respecting k fixed cells.	Medium7	MathCombinatorics+2	No attempts yet	2s	256 MB	Judgeable
MobileGiven a full binary tree of rods and toys, find the minimum number of left-right child swaps so that all toys sit at depths differing by at most 1, with deeper toys to the left.	Medium7	TreeGreedy+2	No attempts yet	1s	128 MB	Judgeable
Party LocationGiven up to 200 house coordinates in a 50 km square, find a party location within 2.5 km of as many houses as possible.	Medium7	GeometryBrute force+2	No attempts yet	1s	128 MB	Judgeable
Shortest Flight PathGiven airports on a sphere, find the shortest route between two airports staying inside the union of radius-R circles and within each fuel leg.	Medium7	GraphShortest path+2	No attempts yet	5s	128 MB	Judgeable
Stacking BowlsGiven several already-sorted stacks of bowls, find the minimum number of split and merge operations to combine them into one globally sorted stack.	Medium7	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Faucet FlowWater pours at 1 cubic unit per second into a 1-wide tank with vertical dividers of given heights; find the time when it first overflows the outermost divider.	Medium7	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Laser TagFind every firing angle from the origin whose laser beam returns to the origin after at most 7 reflections off flat mirrors, and print the angles in order.	Medium7	GeometrySimulation+1	No attempts yet	1s	128 MB	Judgeable
Cell TowersWalk a polyline road at every mile marker, compute each tower's signal p/d^2 rounded to nearest integer, and report only markers where the best tower (ties by alphabetical label) changes.	Medium7	GeometrySimulation+2	No attempts yet	1s	128 MB	Judgeable
TransmittersGiven a fixed center, a radius, and up to 150 points, find the largest number of points that fit inside some semicircular half-disk at any rotation.	Medium7	GeometryTwo pointers+2	No attempts yet	1s	128 MB	Judgeable
Safety in AlchemyGiven reaction heats between pairs of chemicals and limited amounts of each chemical, find the maximum total heat that can be produced.	Medium7	GraphDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Apply a Cold CompressDecode each compression-expression into its smallest pixel picture by parsing split tags and computing the relative scaling of the two halves, then draw the framed grid.	Medium7	RecursionDivide and conquer+2	No attempts yet	1s	128 MB	Judgeable
ClickomaniaGiven a string over uppercase letters, decide whether the one dimensional Clickomania puzzle can be fully cleared.	Medium7	Dynamic programmingIntervals+1	No attempts yet	10s	128 MB	Judgeable
PlanksGiven a 10x10 grid of stumps and several sets of plank lengths, find the minimum number of planks needed to walk from the top-left stump to the bottom-right stump using each plank at most once.	Medium7	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Hop — Don't Walk!Sliding-tile puzzle with walk and hop moves where hops flip the passed tile; find the fewest moves (depth under 10) to make all black tiles contiguous.	Medium7	BFSBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Discrete SpeedFind the fastest route from a start to a goal city where a car enters each road at an integer speed, changes speed by at most 1 per city, starts and ends at speed 1, and cannot U-turn.	Medium7	GraphShortest path+2	No attempts yet	8s	128 MB	Judgeable
CardsGiven blue and red cards with numbers, find the maximum number of blue-red pairs whose two numbers share a common divisor greater than 1.	Medium7	GraphNumber theory+2	No attempts yet	5s	128 MB	Judgeable
Traveling by StagecoachWith up to 8 one-use tickets, each giving a speed, find the fastest route from city a to city b, or report Impossible.	Medium7	GraphShortest path+2	No attempts yet	3s	128 MB	Judgeable
Cookie SelectionProcess a stream of cookie insertions and median requests; each request outputs the upper median of the currently held multiset, supporting up to 600,000 operations.	Medium7	HeapImplementation+2	No attempts yet	1s	128 MB	Judgeable
Allergy TestFind the shortest non-adaptive schedule for applying allergens on a single morning each day so that every reaction pattern identifies exactly the allergy set.	Medium7	CombinatoricsBit manipulation+2	No attempts yet	1s	128 MB	Judgeable