Problems

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Total results29,392 problems

Runaround Numbers
Medium6
Backtracking, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Counting Cows
Medium6
Geometry, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cow Pool
Medium6
Prefix sum, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cows on Parade
Medium6
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Yacht Dice
Medium6
Dynamic programming, Probability+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
100% Orange Juice!
Medium6
Dynamic programming, Probability
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gym Class
Medium6
Array, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Maximizing the Gain
Medium6
Greedy, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Tree
Medium6
Trie, Tree+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Length of the Sequence
Medium6
Math, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Circus Performance
Medium6
Geometry, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gas Stations
Medium6
Greedy, Stack
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Relay
Medium6
Sorting, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Melons
Medium6
Greedy, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Coin Quiz
Medium6
Binary search, Sliding window+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Not a Subsequence
Medium6
Dynamic programming, String matching+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cleaning
Medium6
Sliding window, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Permutations Without Fixed Points
Medium6
Backtracking, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Greatest Common Divisor
Medium6
Sliding window, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Equivalent Strings
Medium6
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
New Word
Medium6
String, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Survey Relay
Medium6
Sorting, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Driver's Dilemma
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tree Cutting
Medium6
Tree, DFS+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Gym Badges
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Freshman Hyeoncheol
Medium6
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Arcade Go?
Medium6
Binary search, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
What if you drop the egg?
Medium6
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fermat's Last Theorem
Medium6
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Sweetest Dessert in the World
Medium6
Math, Recursion+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cocoa... That's Not It
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Hanbyeol's perfect sequence and query class
Medium6
Segment tree, Array
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Bomboni
Medium6
Dynamic programming, Number theory
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Best-of Match Winner
Medium6
Combinatorics, Math
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Oil Producing Nation
Medium6
Prefix sum, Sliding window+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Movie Night
Medium6
Graph, Topological sort+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Room Evacuation
Medium6
Graph, BFS+1
No attempts yet
Time limit
7s
Memory limit
1024 MB
Judgeable
Restore Array
Medium6
Prefix sum, Shortest path
No attempts yet
Time limit
0.6s
Memory limit
1024 MB
Judgeable
Galactic Bonus
Medium6
Math, Binary search+1
No attempts yet
Time limit
0.4s
Memory limit
8 MB
Judgeable
Tower Defense
Medium6
Sorting, Hash map+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Spoiler
Medium6
Probability, Combinatorics+1
No attempts yet
Time limit
0.6s
Memory limit
1024 MB
Judgeable
Interactive Number Guessing
Medium6
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Incredibly Cute Penguin Chicks
Medium6
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Make a Loop
Medium6
Math, Geometry
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Light
Medium6
Combinatorics, Number theory+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Makima's Lunch Pick for Today
Medium6
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hanbyeol, More Than Just Cute
Medium6
BFS, Graph+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
After the End Credits
Medium6
Sorting, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Card Captor Hanbyul
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Movie Director Shom 4
Medium6
Dynamic programming, String+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Longest Unfriendly Subsequence
Medium6
Dynamic programming, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Move the Queen
Medium6
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sigma Sigma Sigma Sigma
Medium6
Combinatorics, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Planting Flags
Medium6
Graph, Union-find
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Round Corridor
Medium6
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Sum Over Zero
Medium6
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Shooting Lasers
Medium6
Math, Sorting
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Yoga Class
Medium6
Graph, DFS
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
1D 2048
Medium6
Greedy, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Common Divisor (More Huge)
Medium6
Number theory, Brute force+1
No attempts yet
Time limit
0.75s
Memory limit
1024 MB
Judgeable
Stone Arranging 2
Medium6
Stack, Hash map
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Advertisement 2
Medium6
Intervals, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Painting
Medium6
Probability, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Find and Replace
Medium6
Recursion, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Moo Route
Medium6
Greedy, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Leaders
Medium6
Array, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Greedy Increasing Subsequences
Medium6
Greedy, Segment tree+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Which Warehouse?
Medium6
Shortest path, Matrix+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Quests from the Queen
Medium6
Dynamic programming, Shortest path+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Treasure Hunter
Medium6
Graph, DFS
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Unique Ability
Medium6
Shortest path, Graph
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sum Mod Pair of A
Medium6
Math, Number theory+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Brain fold (Hard)
Medium6
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Flipping and cutting (Easy)
Medium6
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Internet (Easy)
Medium6
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Minimum Tree Partition
Medium6
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Archery
Medium6
Geometry, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Dijkstra's Nightmare (Easy)
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Intrepid cave explorer
Medium6
Greedy, Tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Quite the cheater!
Medium6
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Jimmy the Acting Teacher
Medium6
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Segment Intersection EX
Medium6
Geometry, Brute force+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Going to the movies
Medium6
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Karl's shopping
Medium6
Graph, BFS
No attempts yet
Time limit
12s
Memory limit
1024 MB
Judgeable
Frogs and Queries
Medium6
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Oil Pipeline I
Medium6
Segment tree, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Edgy Baking
Medium6
Dynamic programming, Geometry+1
No attempts yet
Time limit
15s
Memory limit
1024 MB
Judgeable
Mysterious Road Signs
Medium6
Sliding window, Two pointers+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Graceful Chainsaw Jugglers
Medium6
Math, Greedy
No attempts yet
Time limit
25s
Memory limit
1024 MB
Judgeable
Costume Change
Medium6
Graph, Matrix+1
No attempts yet
Time limit
15s
Memory limit
1024 MB
Judgeable
Board Meeting
Medium6
Math, Binary search+1
No attempts yet
Time limit
60s
Memory limit
1024 MB
Judgeable
Juggle Struggle: Part 1
Medium6
Divide and conquer, Geometry+1
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Expogo
Medium6
Math, Bit manipulation+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Incremental House of Pancakes
Medium6
Greedy, Bit manipulation+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Naming Compromise
Medium6
Dynamic programming, String
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Pen Testing
Medium6
Greedy, Implementation
No attempts yet
Time limit
90s
Memory limit
1024 MB
Judgeable
Adjacent and Consecutive
Medium6
Game theory, Implementation
No attempts yet
Time limit
40s
Memory limit
1024 MB
Judgeable
Large party
Medium6
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Digital Calculator
Medium6
Math, Number theory+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Problem Setting
Medium6
Dynamic programming, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Runaround NumbersFind the smallest Runaround number greater than M, where M has at most 10 digits and no digit repeats or is zero.	Medium6	BacktrackingBrute force+1	No attempts yet	1s	1024 MB	Judgeable
Counting CowsGiven cows and fence segments that split the plane into fields, find the largest cow count in any field, with the outside region as a candidate.	Medium6	GeometryGraph+1	No attempts yet	1s	1024 MB	Judgeable
Cow PoolFind the largest L-shaped pool, counted in gridpoints, that fits in a W by H forest without covering any of the N tree points.	Medium6	Prefix sumBrute force+1	No attempts yet	1s	1024 MB	Judgeable
Cows on ParadeOutput N cows as b or w so that every one of the 2^S color patterns of length S appears as a contiguous block.	Medium6	GraphDFS	No attempts yet	1s	1024 MB	Judgeable
Yacht DiceGiven the used categories and three kept dice, find the best score Hanbyeol can get after rerolling the other two dice.	Medium6	Dynamic programmingProbability+1	No attempts yet	0.5s	1024 MB	Judgeable
100% Orange Juice!Given two characters' health, attack, defense, and evasion, compute the probability that the first player wins under the AI combat rules.	Medium6	Dynamic programmingProbability	No attempts yet	1s	1024 MB	Judgeable
Gym ClassGiven a permutation, sort one segment to maximize the distance between each pair of students, then sum those maximum distances over all pairs.	Medium6	ArraySorting+1	No attempts yet	1s	1024 MB	Judgeable
Maximizing the GainGiven a digit string and a swap penalty y, find the largest number that maximizes the resulting value minus y times the number of adjacent swaps.	Medium6	GreedyImplementation	No attempts yet	1s	1024 MB	Judgeable
The TreePaint whole subtrees of an infinite binary tree, where colors shift by one per left or right step, and report the current color of vertices given by root paths.	Medium6	TrieTree+2	No attempts yet	1s	1024 MB	Judgeable
The Length of the SequenceGiven a total digit count S, find the longest run of consecutive non-negative integers whose concatenated decimal form has exactly S digits, or report -1.	Medium6	MathGreedy	No attempts yet	1s	1024 MB	Judgeable
Circus PerformanceGiven n acrobats with heights and weights, output an order so every three consecutive acrobats have forward stunt efficiency at least the reverse efficiency.	Medium6	GeometrySorting	No attempts yet	1s	1024 MB	Judgeable
Gas StationsGiven gas stations with positions and prices, a budget, and a tank capacity, find the farthest point the car can reach.	Medium6	GreedyStack	No attempts yet	1s	1024 MB	Judgeable
RelayChoose three distinct members and their running order to minimize the relay time, where each runner has a sprint time A and a baton time B.	Medium6	SortingDynamic programming	No attempts yet	1s	1024 MB	Judgeable
MelonsFor each start index x, count the boxes needed to pack melons x through N in order under limit L, and report the weight of the last box.	Medium6	GreedyPrefix sum+2	No attempts yet	1s	1024 MB	Judgeable
Coin QuizPick a threshold b that empties cells holding at most b coins so every k consecutive cells have at least m empty ones, maximizing leftover coins minus b.	Medium6	Binary searchSliding window+1	No attempts yet	1s	1024 MB	Judgeable
Not a SubsequenceGiven two sequences over 1 to k, find the shortest sequence that is a subsequence of neither, using DP over next-occurrence tables.	Medium6	Dynamic programmingString matching+1	No attempts yet	1s	1024 MB	Judgeable
CleaningFor each window of K consecutive zones, visit them from highest to lowest priority and sum the moves between them. Output the minimum total.	Medium6	Sliding windowSegment tree+1	No attempts yet	2s	1024 MB	Judgeable
Permutations Without Fixed PointsGiven n and t, print the first t permutations of 1 to n that have no fixed points, in lexicographic order.	Medium6	BacktrackingCombinatorics+1	No attempts yet	1s	1024 MB	Judgeable
Greatest Common DivisorGiven an array of n numbers and a window length k, find the largest GCD of any contiguous subarray of length k.	Medium6	Sliding windowNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Equivalent StringsGiven pairs of commuting letters, decide whether string t can be reached from s by swapping adjacent commuting letters.	Medium6	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
New WordCount the distinct words formed by joining a non-empty prefix of s with a non-empty suffix of t.	Medium6	StringMath	No attempts yet	1s	1024 MB	Judgeable
Survey RelayGiven each soldier's task count and each task's staffing need, decide whether every task can be filled under any possible survey answers.	Medium6	SortingMath	No attempts yet	1s	1024 MB	Judgeable
Driver's DilemmaFind the smallest maximum discomfort for a drive from district 1 to N within time T, where lowering a road's discomfort to D costs extra travel time.	Medium6	GraphShortest path+1	No attempts yet	1s	1024 MB	Judgeable
Tree CuttingGiven a tree, remove one edge and reconnect the two parts with a new edge so the diameter is as large as possible. Output that maximum diameter.	Medium6	TreeDFS+1	No attempts yet	3s	1024 MB	Judgeable
Gym BadgesGiven each gym's level gain X_i and level cap L_i, find the most gyms you can challenge when your level must be at most L_i before each fight.	Medium6	GreedySorting+1	No attempts yet	1.5s	1024 MB	Judgeable
Freshman HyeoncheolGiven A, B, i, and a huge C, print the i-th decimal digit of A raised to the power B^C.	Medium6	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
Arcade Go?Find the smallest day count i such that writing the numbers 1 through i contains digit K at least N times, where N can have up to 1000 digits.	Medium6	Binary searchDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
What if you drop the egg?Given N eggs and K drops, the task is to find the highest floor that can be verified in every case, modulo 1,000,000,007.	Medium6	CombinatoricsDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Fermat's Last TheoremCount and sum the z^m values where z uses primes of \|x+y\| that divide neither x nor y, and z^m divides \|x^n+y^n\|, modulo 1e9+7.	Medium6	MathNumber theory	No attempts yet	1s	1024 MB	Judgeable
The Sweetest Dessert in the WorldFind the volume and surface area mod 1,000,000,007 after carving a side-N cube M times, keeping only the small cubes that touch the original edges.	Medium6	MathRecursion+1	No attempts yet	1s	1024 MB	Judgeable
Cocoa... That's Not ItGiven the order in which Cocoa places the odd-numbered books, choose each even-numbered book so it lies strictly between its two neighbors in value.	Medium6	GreedySorting+1	No attempts yet	1.5s	1024 MB	Judgeable
Hanbyeol's perfect sequence and query classProcess an array with range chmin, chmax, and add updates, answering range min, max, and sum queries.	Medium6	Segment treeArray	No attempts yet	6s	1024 MB	Judgeable
BomboniCount the right-and-down paths from top-left to bottom-right, avoiding obstacles, whose candy values multiply to a number divisible by k, modulo 998244353.	Medium6	Dynamic programmingNumber theory	No attempts yet	2s	1024 MB	Judgeable
Best-of Match WinnerCount the A/B game result strings where Bob reaches M wins to take the series, and Albert reaches N wins before Bob reaches N, modulo 1e9+7.	Medium6	CombinatoricsMath	No attempts yet	0.5s	512 MB	Judgeable
Oil Producing NationPick a contiguous arc of districts on a circle that contains at least K threat districts, maximizing the sum of the A values.	Medium6	Prefix sumSliding window+1	No attempts yet	1s	512 MB	Judgeable
Movie NightCount the nonempty friend subsets where every invited friend's required companion is also invited, modulo 1e9+7.	Medium6	GraphTopological sort+1	No attempts yet	1.5s	1024 MB	Judgeable
Room EvacuationGiven a grid with people, walls, and exits, find how many people can reach an exit within t seconds, with one person per cell at a time.	Medium6	GraphBFS+1	No attempts yet	7s	1024 MB	Judgeable
Restore ArrayFind a 0/1 array of length N that meets M constraints on the k-th smallest value in each subarray, or report -1 if none exists.	Medium6	Prefix sumShortest path	No attempts yet	0.6s	1024 MB	Judgeable
Galactic BonusFor each age up to 2^64 - 1, find the smallest base in which the number has exactly two digits equal to 1 and all other digits 0.	Medium6	MathBinary search+1	No attempts yet	0.4s	8 MB	Judgeable
Tower DefensePlace one laser tower on an empty cell to maximize the points from enemies hit by its four beams, which stop at rocks or the grid edge.	Medium6	SortingHash map+1	No attempts yet	0.5s	1024 MB	Judgeable
SpoilerGiven N (best-of-N) and K (games played), find the expected number of games before the winner becomes predictable, as an irreducible fraction.	Medium6	ProbabilityCombinatorics+1	No attempts yet	0.6s	1024 MB	Judgeable
Interactive Number GuessingFind a secret integer below 10^18 by querying a non-negative offset a and receiving the digit sum of x + a.	Medium6	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Incredibly Cute Penguin ChicksCount the ways to split S into one or more pieces where one of C, I, P appears strictly more often than the other two, which are equal. Output modulo 998244353.	Medium6	Dynamic programmingPrefix sum+2	No attempts yet	6s	1024 MB	Judgeable
Make a LoopGiven n quarter-circle rail tracks with radii r_1 to r_n, decide whether all of them can be joined smoothly into one closed loop.	Medium6	MathGeometry	No attempts yet	2s	1024 MB	Judgeable
LightGiven N bulbs and K divisors d_i, count the bulbs that are flipped an odd number of times.	Medium6	CombinatoricsNumber theory+1	No attempts yet	2s	1024 MB	Judgeable
Makima's Lunch Pick for TodayFind the restaurant that Power, Denji, and Aki can each reach by walks of the same length over one-way roads, minimizing that length, and print their walks.	Medium6	GraphBFS+1	No attempts yet	1s	1024 MB	Judgeable
Hanbyeol, More Than Just CuteFind the shortest path from school S to home H on a grid where you cannot step back to the previous cell and any three most recent cells sum to at most K.	Medium6	BFSGraph+1	No attempts yet	1.5s	1024 MB	Judgeable
After the End CreditsChoose K-1 of N candidates to join the hero Y so that one member's total skill difference to the rest of the party is minimized, then print that minimum.	Medium6	SortingPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Card Captor HanbyulFind the shortest route from vertex 1 that visits all N card vertices in a directed graph, where a vertex can be entered only if its power is at most the cards held.	Medium6	GraphShortest path+1	No attempts yet	1s	1024 MB	Judgeable
Movie Director Shom 4Given an apocalyptic number up to 10^18, find its position among all numbers that contain three consecutive 6s, in increasing order.	Medium6	Dynamic programmingString+1	No attempts yet	0.5s	1024 MB	Judgeable
Longest Unfriendly SubsequenceGiven a sequence, find the length of the longest subsequence where any two elements at distance at most 2 are different.	Medium6	Dynamic programmingArray+1	No attempts yet	1s	1024 MB	Judgeable
Move the QueenCount the ways a queen can reach the target square in exactly K moves on a board with obstacles, never repeating the same direction twice in a row.	Medium6	Dynamic programmingPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Sigma Sigma Sigma SigmaGiven N integers, compute the nested sigma sum of max(A_k, A_l) over all valid index ranges, modulo 998244353.	Medium6	CombinatoricsSorting+1	No attempts yet	1s	1024 MB	Judgeable
Planting FlagsPlant flags on buildings so every ground passage has a flagged end and each skywalk-connected group has at most one flag, or report NO.	Medium6	GraphUnion-find	No attempts yet	2s	1024 MB	Judgeable
Round CorridorGiven a round corridor with n inner and m outer sectors, decide for each query whether one sector can be reached from another.	Medium6	Number theoryMath	No attempts yet	1s	256 MB	Judgeable
Sum Over ZeroChoose pairwise disjoint segments whose element sums are all non-negative, maximizing the total length of the chosen segments.	Medium6	Dynamic programmingPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Shooting LasersGiven sensors in a strip with mirror walls, find the launch angle from (0, 0) that lights the most sensors using fewer than K wall reflections.	Medium6	MathSorting	No attempts yet	1.5s	1024 MB	Judgeable
Yoga ClassDecide whether some set of movements covers each replacement pair and never includes both movements of a conflicting pair.	Medium6	GraphDFS	No attempts yet	2s	1024 MB	Judgeable
1D 2048Given a sequence of powers of two and zeros, merge equal values by doubling one and zeroing the other to find the largest possible maximum.	Medium6	GreedyArray+1	No attempts yet	1s	1024 MB	Judgeable
Common Divisor (More Huge)Given G and the prime factorization of L, find the pair (a, b) with gcd G and lcm L that has the smallest a+b, breaking ties by smallest a.	Medium6	Number theoryBrute force+1	No attempts yet	0.75s	1024 MB	Judgeable
Stone Arranging 2Stones are placed one by one, and each new stone repaints the stones after the last one with its color. Output the final colors.	Medium6	StackHash map	No attempts yet	2s	1024 MB	Judgeable
Advertisement 2Given each resident's coordinate and influence power, find the fewest residents to donate copies to so that everyone ends up with a copy.	Medium6	IntervalsSorting+1	No attempts yet	2s	1024 MB	Judgeable
PaintingGiven n parts with distinct colours and t random repaint steps, find the probability that at least k colours remain, modulo 1000000007.	Medium6	ProbabilityMatrix+1	No attempts yet	1s	1024 MB	Judgeable
Find and ReplaceStarting from "a", apply letter-to-string replacements, then print the substring from position l to position r of the final string.	Medium6	RecursionDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
Moo RouteGiven how many times Bessie crosses each half-integer line, build a closed L/R walk from 0 back to 0 with the fewest direction changes.	Medium6	GreedyImplementation	No attempts yet	2s	1024 MB	Judgeable
LeadersGiven each cow's breed and reach E_i, count the Guernsey and Holstein leader pairs where each leader's range covers all of its breed or the other leader.	Medium6	ArrayPrefix sum+1	No attempts yet	2s	1024 MB	Judgeable
Greedy Increasing SubsequencesRepeatedly extract greedy increasing chains that take each next larger element, removing used numbers, until the sequence is empty, and list every chain.	Medium6	GreedySegment tree+1	No attempts yet	5s	1024 MB	Judgeable
Which Warehouse?Assign each of m products to a distinct warehouse so that the total distance of moving all product units is minimized.	Medium6	Shortest pathMatrix+1	No attempts yet	3s	1024 MB	Judgeable
Quests from the QueenFind the minimum time for Athin to visit K quest cities and return to city 1 on a weighted road graph, given a teleport that recharges in S time.	Medium6	Dynamic programmingShortest path+1	No attempts yet	3s	1024 MB	Judgeable
Treasure HunterFind the fewest teleports needed to visit every treasure junction in a directed graph, starting from any junction.	Medium6	GraphDFS	No attempts yet	2s	1024 MB	Judgeable
Unique AbilityFind the minimum time from city 1 to city N when each road needs a matching group ID and switching IDs costs the absolute difference.	Medium6	Shortest pathGraph	No attempts yet	2s	1024 MB	Judgeable
Sum Mod Pair of AGiven array A and a power of 2 M, find the sum of all elements of SMPA^K(A, M) modulo 998244353 when K can be as large as 10^9.	Medium6	MathNumber theory+1	No attempts yet	1.5s	1024 MB	Judgeable
Brain fold (Hard)Given a sheet of paper, a sequence of folds, and one final cut, count the resulting pieces modulo 1e9+7.	Medium6	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Flipping and cutting (Easy)Given a circle with circumference c and a step length sqrt(s), find the minimum number of wedge flips after which the circle is fully black again, or report that it never happens.	Medium6	Number theoryMath+1	No attempts yet	1s	1024 MB	Judgeable
Internet (Easy)Given a directed graph, list the servers that every walk from server 1 to server n passes through exactly once, in path order.	Medium6	GraphDFS+1	No attempts yet	1s	1024 MB	Judgeable
Minimum Tree PartitionGiven a tree with target weights A_i, find the fewest operations that each add 1 to a connected vertex subset so every vertex i reaches A_i.	Medium6	TreeDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
ArcheryGiven N points, peel convex hulls layer by layer, then print for each of Q arrow points the number of layers it falls inside.	Medium6	GeometryBinary search+1	No attempts yet	2s	1024 MB	Judgeable
Dijkstra's Nightmare (Easy)Construct a graph with negative edges on which the reference Dijkstra implementation terminates while processing at least 10000 vertices.	Medium6	Shortest pathGraph+1	No attempts yet	1s	1024 MB	Judgeable
Intrepid cave explorerGiven a rooted tree, assign each node a string of white and pink dots so ancestors are prefixes and unrelated pairs are not, minimizing total dots.	Medium6	GreedyTree+1	No attempts yet	1s	1024 MB	Judgeable
Quite the cheater!Given a mean mu and a variance v, build between 10 and 1000 integers whose mean is exactly mu and whose population variance is at least v (or exactly v).	Medium6	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Jimmy the Acting TeacherGiven N, assign blue and red table numbers so every man and woman pair meets exactly once over N rounds, or report Impossible.	Medium6	MathNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Segment Intersection EXGiven N segments, classify every pair (including each segment with itself) as disjoint, touching at an endpoint, crossing at an interior point, or overlapping.	Medium6	GeometryBrute force+1	No attempts yet	1s	512 MB	Judgeable
Going to the moviesGiven N girls and K seats with random tickets, find the probability that at least one girl is thrown out, as a reduced fraction.	Medium6	MathCombinatorics	No attempts yet	1s	1024 MB	Judgeable
Karl's shoppingGiven item prices and vouchers that each cover only some items, find the minimum cash Karl must pay after using the vouchers optimally.	Medium6	GraphBFS	No attempts yet	12s	1024 MB	Judgeable
Frogs and QueriesGiven an N by N grid of move costs, find for each query the minimum time for a frog to reach the right edge using at most one upward jump of length at least L.	Medium6	Dynamic programmingPrefix sum+1	No attempts yet	1s	128 MB	Judgeable
Oil Pipeline IEach type 2 event adds C to every plant whose pipeline passes station I, and the task lists the plants that start running.	Medium6	Segment treeImplementation	No attempts yet	2s	1024 MB	Judgeable
Edgy BakingEach of N rectangular cookies can stay whole or be cut through its center into two equal-area halves. Find the largest total perimeter that does not exceed P.	Medium6	Dynamic programmingGeometry+1	No attempts yet	15s	1024 MB	Judgeable
Mysterious Road SignsFind the longest contiguous run of signs where each sign matches one shared west-facing value or one shared east-facing value, and count such runs.	Medium6	Sliding windowTwo pointers+1	No attempts yet	10s	1024 MB	Judgeable
Graceful Chainsaw JugglersGiven R red and B blue chainsaws, find the most jugglers you can use when every chainsaw is used and no two jugglers have the same red and blue counts.	Medium6	MathGreedy	No attempts yet	25s	1024 MB	Judgeable
Costume ChangeGiven an N by N grid of signed costume values, find the fewest cells to recolor so that no costume value repeats within any row or column.	Medium6	GraphMatrix+1	No attempts yet	15s	1024 MB	Judgeable
Board MeetingFind a meeting cell that minimizes the total Chebyshev distance to N kings whose number and coordinates are unknown to you.	Medium6	MathBinary search+1	No attempts yet	60s	1024 MB	Judgeable
Juggle Struggle: Part 1Given 2N points with no three collinear, pair them up so that every two segments between pairs cross.	Medium6	Divide and conquerGeometry+1	No attempts yet	Not set	1024 MB	Judgeable
ExpogoFind the shortest string of N, S, E, W jumps of length 1, 2, 4, and so on that lands exactly on (X, Y), or report IMPOSSIBLE.	Medium6	MathBit manipulation+1	No attempts yet	20s	1024 MB	Judgeable
Incremental House of PancakesCustomers arrive in order and each takes i pancakes from the larger of two stacks, so the task is to count how many are served and what remains.	Medium6	GreedyBit manipulation+1	No attempts yet	20s	1024 MB	Judgeable
Naming CompromiseGiven two strings C and J, find a non-empty name N minimizing the sum of its edit distances to both, breaking ties by balancing the two distances.	Medium6	Dynamic programmingString	No attempts yet	20s	1024 MB	Judgeable
Pen TestingGiven N pens holding each ink amount from 0 to N-1 once, find two pens with at least N ink total, using write attempts that drain ink to probe them.	Medium6	GreedyImplementation	No attempts yet	90s	1024 MB	Judgeable
Adjacent and ConsecutiveTwo players alternately place numbered tiles into a row of N cells, and the task is to count each player's moves that hand the opponent a forced win.	Medium6	Game theoryImplementation	No attempts yet	40s	1024 MB	Judgeable
Large partyCount circular seatings of N people as men or women, treating rotations as equal, where no more than K women sit in a row.	Medium6	CombinatoricsDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Digital CalculatorGiven N, K, and L, print the first K digits and the last L digits of N factorial.	Medium6	MathNumber theory+1	No attempts yet	10s	1024 MB	Judgeable
Problem SettingCount nonempty subsets of problems whose easy/hard rating vectors form a chain under inclusion, modulo 1e9+7, with N up to 1e5 and M up to 20.	Medium6	Dynamic programmingBit manipulation	No attempts yet	1s	1024 MB	Judgeable