Problems

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Total results29,445 problems

Array
Medium5
Math, Greedy
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Alice and Path
Medium5
Simulation, Geometry+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Painter
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Subnumber Sum
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Shell Game
Medium5
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Card Control
Medium5
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Remove the Median
Medium5
Heap, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Boredom Buster
Medium5
Implementation, Simulation+1
No attempts yet
Time limit
12s
Memory limit
1024 MB
Judgeable
Silver Star Stands Alone
Medium5
Dynamic programming, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Eidam Sand Lair
Medium5
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Organ-free Man
Medium5
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Frog
Medium5
Greedy, String+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Matchsticks
Medium5
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Power Outlets
Medium5
Greedy, Heap+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Trimming the Tree
Medium5
Greedy, Tree+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Battle of Giants
Medium5
Math, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Air Cownditioning
Medium5
Array, Greedy+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Algorithm Class - Selection Sort 5
Medium5
Implementation, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Robot Path Decoding
Medium5
Stack, String+2
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Alien Piano
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
High Buildings
Medium5
Greedy, Implementation+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Metal Harvest
Medium5
Greedy, Intervals+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Energy Stones
Medium5
Greedy, Dynamic programming+1
No attempts yet
Time limit
30s
Memory limit
1024 MB
Judgeable
Latest Guests
Medium5
Simulation, Math
No attempts yet
Time limit
15s
Memory limit
1024 MB
Judgeable
The Equation
Medium5
Bit manipulation, Greedy
No attempts yet
Time limit
15s
Memory limit
1024 MB
Judgeable
Diagonal Puzzle
Medium5
Graph, BFS
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Even Digits
Medium5
Greedy, Math+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Planet Distance
Medium5
Graph, BFS+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Yogurt
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Algorithm Class - Bubble Sort 1
Medium5
Simulation, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Bubble Sort 3
Medium5
Sorting, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Even Game
Medium5
Game theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Big Buttons
Medium5
String, Trie+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Mural
Medium5
Sliding window, Greedy+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Square Counting
Medium5
Math, Combinatorics+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Pattern Overlap
Medium5
String, String matching+1
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Ambiguous Cipher
Medium5
Math, Implementation+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Trapezoid Counting
Medium5
Sorting, Combinatorics+1
No attempts yet
Time limit
30s
Memory limit
1024 MB
Judgeable
Cake
Medium5
Dynamic programming, Math+2
No attempts yet
Time limit
30s
Memory limit
1024 MB
Judgeable
Kicksort
Medium5
Array, Simulation+2
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Word Search
Medium5
Implementation, Matrix+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Algorithm Class - Insertion Sort 1
Medium5
Sorting, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Insertion Sort 3
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Real Numbers
Medium5
Math, Number theory+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Algorithm Class - Quick Sort 1
Medium5
Sorting, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Quick Sort 2
Medium5
Sorting, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
UFO Airfield (UFO) 4
Medium5
Greedy, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
JOI Poster
Medium5
Divide and conquer, Recursion+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Nile.Com
Medium5
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mall
Medium5
Prefix sum, Sliding window+2
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Anagram
Medium5
Combinatorics, Math+2
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Moving
Medium5
Backtracking, Matrix
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Muffinspelet
Medium5
Game theory, Greedy+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Elder price robot
Medium5
Stack, Array+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Glitching screen
Medium5
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Junior price robot
Medium5
Array, Stack+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Live Aid
Medium5
Dynamic programming, Sorting+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Meticulous smoothing
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Queue
Medium5
Math, Binary search
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Rods
Medium5
Greedy, Brute force+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Report
Medium5
Stack, Array+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Square
Medium5
Dynamic programming, Matrix+1
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Workshop
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hidden Pencil Cases
Medium5
Array, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
КАРТИ
Medium5
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Coding
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Triangles
Medium5
Sorting, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
PALINDROME
Medium5
String, String matching+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Swaps
Medium5
Simulation, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pigeon Cells
Medium5
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
ПОДНИЗ
Medium5
String, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Next Number
Medium5
Greedy, String
No attempts yet
Time limit
0.1s
Memory limit
8 MB
Judgeable
Algorithm Class - Selection Algorithm 1
Medium5
Simulation, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Selection Algorithm 2
Medium5
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Letter
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Algorithm Class - Matrix Path Problem 2
Medium5
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Strawberry 2
Medium5
Sliding window, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Egoi Exhibition (EGOI Exhibition)
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Algorithm Class - Matrix Path Problem 4
Medium5
Dynamic programming, Matrix+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Similar Rhyme Game
Medium5
Trie, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bracket String Notation (Small)
Medium5
Dynamic programming, Math
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Lucky Number Test
Medium5
Implementation, Simulation+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Algorithm Class - Breadth First Search 4
Medium5
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Carpet
Medium5
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Debugging
Medium5
Two pointers, Sliding window+2
No attempts yet
Time limit
0.6s
Memory limit
512 MB
Judgeable
Graph Stem
Medium5
Tree, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Maze
Medium5
Tree, DFS+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Feeding Duksu
Medium5
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Depth-First Search 6
Medium5
DFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Searching for Soulmates
Medium5
Math, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Non-Transitive Dice
Medium5
Brute force, Probability+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
blobaww
Medium5
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
blobhyperthink
Medium5
Dynamic programming, Prefix sum
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
queuestack
Medium5
Queue, Stack+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Card Game and Queries
Medium5
Math, Game theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Abridged Reading
Medium5
Tree, DFS+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Noonerized Spumbers
Medium5
Brute force, String+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Recycling
Medium5
Stack, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bracket Pairing
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
7s
Memory limit
1024 MB
Judgeable
Parking Lot
Medium5
Shortest path, Geometry+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
ArrayRearrange the array so that taking the running value mod each later element leaves the largest possible final value.	Medium5	MathGreedy	No attempts yet	3s	256 MB	Judgeable
Alice and PathSimulate the walk on the triangular grid, store the visited triangles, then retrace them in reverse to print steps that return Alice to the start.	Medium5	SimulationGeometry+1	No attempts yet	2s	256 MB	Judgeable
PainterEach target color is a subset of red, yellow, and blue; find the fewest interval strokes of primary colors whose combined effect matches the painting.	Medium5	Dynamic programmingGreedy+2	No attempts yet	Not set	1024 MB	Judgeable
Subnumber SumSplit the digits of an N-digit number (N up to 18) into a K-digit subnumber and an (N-K)-digit subnumber, both keeping digit order, and maximize their sum.	Medium5	Dynamic programmingGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Shell GameGiven a start vertex and an exact number of moves Y, find every vertex reachable by a walk of length exactly Y in an undirected graph.	Medium5	GraphBFS+2	No attempts yet	1s	1024 MB	Judgeable
Card ControlGiven a shuffled deck of N O cards and N X cards, find the fewest cards Junseok must move to the top so that he wins the pairwise card game.	Medium5	GreedyMath+1	No attempts yet	1s	512 MB	Judgeable
Remove the MedianGiven N numbers, repeatedly replace the median with its half (rounded down) until a 0 appears, and count the operations needed.	Medium5	HeapSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Boredom BusterFind the number on every card in a memory game where each move reveals two cards, which are then reshuffled face down, so the program must track what it has seen.	Medium5	ImplementationSimulation+1	No attempts yet	12s	1024 MB	Judgeable
Silver Star Stands AloneCount the ways to travel along the prime-distance asteroids from 2 to prime P, visiting 2 and P, with consecutive stops at most 14 AU apart.	Medium5	Dynamic programmingNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Eidam Sand LairFor each test case, find the minimum time for a person at floor Yp to reach floor 0, either walking, riding the lift from floor Lp, or meeting it at an intermediate floor.	Medium5	MathGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Organ-free ManGiven y, find the smallest non-negative integer x such that f(x) equals y, where f sums digit factorials of x.	Medium5	MathGreedy+2	No attempts yet	1s	1024 MB	Judgeable
FrogGiven a string of K and P, split it into the fewest subsequences, each alternating between K and P, and output that count.	Medium5	GreedyString+2	No attempts yet	1s	512 MB	Judgeable
MatchsticksGiven N matchsticks, find any two-digit equation AB+CD=EF that uses exactly N sticks, counting two each for the plus and equals signs.	Medium5	Brute forceImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Power OutletsAssign N devices with power-of-two charge times to M identical outlets to finish all charging as early as possible.	Medium5	GreedyHeap+2	No attempts yet	1s	1024 MB	Judgeable
Trimming the TreeGiven a tree rooted at node 1 and a limit K per level, remove subtrees so that each level keeps at most K nodes, and find the maximum number of nodes kept.	Medium5	GreedyTree+2	No attempts yet	1s	1024 MB	Judgeable
The Battle of GiantsGiven a final score a:b, decide whether it can result from matches worth 3 points for a win and 1 for a draw, and if so print win, draw, win counts using the fewest matches.	Medium5	MathGreedy+1	No attempts yet	1s	512 MB	Judgeable
Air CownditioningGiven preferred and current temperatures per stall, find the minimum number of range-increment or range-decrement commands to reach the target.	Medium5	ArrayGreedy+2	No attempts yet	2s	1024 MB	Judgeable
Algorithm Class - Selection Sort 5Given two arrays of N distinct integers, decide whether array A equals array B at some moment during selection sort, counting the initial state.	Medium5	ImplementationSorting+2	No attempts yet	1s	512 MB	Judgeable
Robot Path DecodingParse a program with nested repeat groups and report the rover's final wrapped position on a 10^9 by 10^9 torus.	Medium5	StackString+2	No attempts yet	10s	1024 MB	Judgeable
Alien PianoGiven a sequence of pitches, assign each to one of 4 ordered keys so that relative comparisons are preserved as often as possible, minimizing rule breaks.	Medium5	Dynamic programmingGreedy+2	No attempts yet	Not set	1024 MB	Judgeable
High BuildingsConstruct heights for N buildings so that exactly A are visible from the left, B from the right, and C from both, or report that no such heights exist.	Medium5	GreedyImplementation+1	No attempts yet	20s	1024 MB	Judgeable
Metal HarvestGiven sorted non-overlapping harvesting intervals and a maximum deployment length K, find the minimum number of robots needed so every allowed time unit is harvested.	Medium5	GreedyIntervals+2	No attempts yet	20s	1024 MB	Judgeable
Energy StonesGiven each stone's eating time, starting energy, and per-second decay, find the maximum total energy Duda can receive by choosing which stones to eat and in what order.	Medium5	GreedyDynamic programming+1	No attempts yet	30s	1024 MB	Judgeable
Latest GuestsGiven N consulates on a circular street and guests moving clockwise or anti-clockwise for M minutes, count how many consulates each guest was the last to visit.	Medium5	SimulationMath	No attempts yet	15s	1024 MB	Judgeable
The EquationGiven N integers and a limit M, find the largest k such that the sum of each A_i XOR k is at most M, or report -1 if no k works.	Medium5	Bit manipulationGreedy	No attempts yet	15s	1024 MB	Judgeable
Diagonal PuzzleGiven an N by N grid of black and white squares, find the fewest diagonal flips that turn every square black.	Medium5	GraphBFS	No attempts yet	20s	1024 MB	Judgeable
Even DigitsGiven an integer N, find the minimum number of +1/-1 steps to reach a number whose decimal digits are all even.	Medium5	GreedyMath+2	No attempts yet	20s	1024 MB	Judgeable
Planet DistanceIn a connected graph with exactly one cycle, find each node's distance to the nearest node on that unique cycle.	Medium5	GraphBFS+2	No attempts yet	20s	1024 MB	Judgeable
YogurtEach yogurt cup expires A_i days from today and cannot be eaten on or after that day; with at most K cups eaten per day, find the maximum number of cups Lucy can consume starting today.	Medium5	GreedySorting+2	No attempts yet	20s	1024 MB	Judgeable
Algorithm Class - Bubble Sort 1Given an array and a swap count K, report the two values swapped by the K-th exchange in the given bubble sort, or -1 if fewer than K swaps occur.	Medium5	SimulationSorting+2	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Bubble Sort 3Given distinct arrays A and B, decide whether bubble sort run on A reaches a state equal to B at some point, including the initial state.	Medium5	SortingImplementation+2	No attempts yet	1s	512 MB	Judgeable
Even GameGiven Yungu's initial coins N and K coins on the board, players alternately take 1 to 4 coins; Yungu wins if his final total is even.	Medium5	Game theoryDynamic programming+2	No attempts yet	1s	512 MB	Judgeable
Big ButtonsCount the length-N strings over {R,B} that do not start with any of P given forbidden prefixes, where some prefixes may contain others.	Medium5	StringTrie+2	No attempts yet	20s	1024 MB	Judgeable
MuralGiven a digit string of wall beauty scores, find the maximum total beauty Thanh can guarantee when each day he paints a section adjacent to painted ones and an unpainted end section crumbles.	Medium5	Sliding windowGreedy+2	No attempts yet	20s	1024 MB	Judgeable
Square CountingCount all squares whose four vertices are dots of an R by C grid, including tilted squares, and report the total modulo 1e9+7.	Medium5	MathCombinatorics+1	No attempts yet	20s	1024 MB	Judgeable
Pattern OverlapGiven two patterns where each star matches 0 to 4 letters, decide whether some title matches both patterns.	Medium5	StringString matching+1	No attempts yet	Not set	1024 MB	Judgeable
Ambiguous CipherGiven an encrypted word produced by summing each letter's neighbors mod 26, recover the original word or report that it is ambiguous.	Medium5	MathImplementation+2	No attempts yet	20s	1024 MB	Judgeable
Trapezoid CountingGiven stick lengths, count the sets of four sticks that can form an isosceles trapezoid with exactly one pair of parallel sides.	Medium5	SortingCombinatorics+1	No attempts yet	30s	1024 MB	Judgeable
CakeGiven N, find the fewest perfect squares that sum to N, since each cake is a square with integer side length.	Medium5	Dynamic programmingMath+2	No attempts yet	30s	1024 MB	Judgeable
KicksortGiven a permutation of 1..N, decide whether every pivot Kicksort picks during its recursion is a worst-case pivot.	Medium5	ArraySimulation+2	No attempts yet	Not set	1024 MB	Judgeable
Word SearchBuild a grid of I, /, and O with at most D rows and D columns that contains exactly N occurrences of I/O in any of eight directions.	Medium5	ImplementationMatrix+1	No attempts yet	20s	1024 MB	Judgeable
Algorithm Class - Insertion Sort 1Simulate insertion sort on N distinct integers, track each element write, and print the value written on the K-th store or -1 if there are fewer than K writes.	Medium5	SortingSimulation+2	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Insertion Sort 3Simulate insertion sort on array A and print 1 if the array ever equals B during the process, otherwise 0.	Medium5	SimulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
Real NumbersGiven two numbers of the form (b + c*sqrt(d))/a, compute and print their sum, difference, product, and quotient in the same canonical form.	Medium5	MathNumber theory+2	No attempts yet	0.5s	512 MB	Judgeable
Algorithm Class - Quick Sort 1Run the given quick sort partition routine on an array of N distinct integers and print the two values swapped at the K-th swap, or -1 if fewer than K swaps occur.	Medium5	SortingDivide and conquer+2	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Quick Sort 2Simulate the given quick sort partition scheme and print the array right after the K-th swap, or -1 if fewer swaps happen.	Medium5	SortingSimulation+2	No attempts yet	1s	512 MB	Judgeable
UFO Airfield (UFO) 4Place as many copies of a small UFO shape as possible in a grid while no occupied cells from different UFOs share an edge.	Medium5	GreedySimulation+1	No attempts yet	1s	1024 MB	Judgeable
JOI PosterGiven N and K, print row K of a recursively defined 2^N by 2^N poster built from J, O, and I quadrants.	Medium5	Divide and conquerRecursion+2	No attempts yet	1s	1024 MB	Judgeable
Nile.ComChoose one of N stores each day for D days to minimize total cost, with 10% off for a store used two days in a row and 30% off for three or more.	Medium5	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
MallIn an m by n grid where some blocks are blocked, find the a by b all-free rectangle with the smallest sum of block costs.	Medium5	Prefix sumSliding window+2	No attempts yet	6s	1024 MB	Judgeable
AnagramGiven a string of up to 20 uppercase letters, find its 1-based lexicographic rank among all distinct permutations of its characters.	Medium5	CombinatoricsMath+2	No attempts yet	0.5s	1024 MB	Judgeable
MovingCount the ways to cover every floor cell of an H by W grid with non-overlapping L-shaped carpets of 3 cells, where walls cannot be covered.	Medium5	BacktrackingMatrix	No attempts yet	8s	1024 MB	Judgeable
MuffinspeletTwo players alternately split a pile of N muffins and eat one of the two parts; compute each player's total with optimal play.	Medium5	Game theoryGreedy+2	No attempts yet	2s	1024 MB	Judgeable
Elder price robotFor each day, report how many days back the price was last lower than or equal to today's price, or infinity if no earlier price was that low.	Medium5	StackArray+2	No attempts yet	4s	1024 MB	Judgeable
Glitching screenGiven n candidate h by w pixel renderings and a current screen that may have dead pixels stuck off, decide whether exactly one stop matches.	Medium5	StringImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Junior price robotGiven today's price first and earlier prices after, report how many days back the most recent day with a price no higher than today's is.	Medium5	ArrayStack+1	No attempts yet	1s	1024 MB	Judgeable
Live AidGiven n musicians, each with a start time, end time, and attention value, choose a non-overlapping subset that maximizes total attention.	Medium5	Dynamic programmingSorting+2	No attempts yet	3s	1024 MB	Judgeable
Meticulous smoothingGiven a plank's thickness at n positions, shave off 1 micrometer at a time so that neighboring thicknesses differ by at most 1; find the minimum number of shaves.	Medium5	Dynamic programmingGreedy+2	No attempts yet	1s	1024 MB	Judgeable
QueueGiven N and K, the task is to find the smallest starting queue size that grows to exactly N after repeated group arrivals with the fixed gap pattern.	Medium5	MathBinary search	No attempts yet	0.5s	1024 MB	Judgeable
RodsGiven three rod lengths with limited counts of each, find the fewest rods whose total length reaches at least L, or print 0 if impossible.	Medium5	GreedyBrute force+2	No attempts yet	1s	1024 MB	Judgeable
ReportFor each day, find the nearest earlier day whose income is smaller; print its index, or 0 if none exists.	Medium5	StackArray+2	No attempts yet	1s	1024 MB	Judgeable
SquareGiven a table of 0s and 1s, find the largest odd side length of a square whose two diagonals contain only 1s.	Medium5	Dynamic programmingMatrix+1	No attempts yet	2.5s	1024 MB	Judgeable
WorkshopGiven n parts and two identical machines, decide whether all parts can be scheduled on the two machines within a total time limit T.	Medium5	Dynamic programmingGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Hidden Pencil CasesGiven an N by M grid of case heights and a pencil of length H, count cells where a pencil of height H placed inside is hidden from every perpendicular side view.	Medium5	ArrayImplementation+2	No attempts yet	1s	1024 MB	Judgeable
КАРТИGiven four integers (each up to 9999), arrange them in some order and concatenate so the resulting number is as large as possible.	Medium5	SortingGreedy+2	No attempts yet	1s	1024 MB	Judgeable
CodingCount how many distinct strings result from replacing some non-overlapping adjacent digit pairs (values 10 to 10+n-1) with letters a to z.	Medium5	Dynamic programmingString+2	No attempts yet	1s	1024 MB	Judgeable
TrianglesCount triples of segments, one of each color, that satisfy the strict triangle inequality on their lengths.	Medium5	SortingTwo pointers+2	No attempts yet	1s	1024 MB	Judgeable
PALINDROMEGiven a non-palindrome string, find the minimum length after prepending letters to make it a palindrome.	Medium5	StringString matching+2	No attempts yet	1s	1024 MB	Judgeable
SwapsGiven a permutation of 1 to N, print a sequence of adjacent swaps that sorts it, where a swap is allowed only if neither element is already in its correct position.	Medium5	SimulationArray	No attempts yet	1s	1024 MB	Judgeable
Pigeon CellsPlace K pigeons in N cells to maximize the smallest gap between neighbors, then count how many adjacent pairs achieve that smallest gap.	Medium5	MathGreedy+2	No attempts yet	1s	1024 MB	Judgeable
ПОДНИЗFind the longest string that can appear as a substring of some permutation of a and of some permutation of b, breaking ties by lexicographic order.	Medium5	StringGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Next NumberGiven a non-negative integer A, find the smallest integer greater than A whose digits are all different, or report -1 if none exists.	Medium5	GreedyString	No attempts yet	0.1s	8 MB	Judgeable
Algorithm Class - Selection Algorithm 1Simulate the given quickselect pseudocode on the array and report the two values swapped at the K-th swap, or -1 if fewer than K swaps occur.	Medium5	SimulationDivide and conquer+2	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Selection Algorithm 2Simulate the given quickselect pseudocode and output the array after exactly K swaps, or -1 if the algorithm finishes with fewer than K swaps.	Medium5	ImplementationSimulation+2	No attempts yet	1s	512 MB	Judgeable
LetterApply a repeating list of swap and alphabet-shift rules to a string K times, where K is up to 10^12, and print the result.	Medium5	SimulationImplementation+2	No attempts yet	2s	512 MB	Judgeable
Algorithm Class - Matrix Path Problem 2Count how many times the base-case line of the recursive matrix path pseudocode runs, and how many times the DP transition line runs, for an n by n grid.	Medium5	Dynamic programmingCombinatorics+2	No attempts yet	1s	512 MB	Judgeable
Strawberry 2Place a 3x3 square on a huge grid and maximize the number of given points it covers.	Medium5	Sliding windowSorting+2	No attempts yet	1s	1024 MB	Judgeable
Egoi Exhibition (EGOI Exhibition)Choose a subset of the paintings in a row, keeping the order, so no two adjacent kept paintings share a type, maximizing the sum of their values.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	1024 MB	Judgeable
Algorithm Class - Matrix Path Problem 4In an n by n grid moving only right or down, find the maximum path score from top-left to bottom-right that visits at least one of P given cells.	Medium5	Dynamic programmingMatrix+2	No attempts yet	1s	512 MB	Judgeable
Similar Rhyme GameGiven n distinct words, pair them up so that each pair shares a common suffix of length at least F, maximizing the number of pairs.	Medium5	TrieGreedy+2	No attempts yet	1s	512 MB	Judgeable
Bracket String Notation (Small)Given N, find the shortest bracket string whose value is N, breaking length ties by lexicographic order.	Medium5	Dynamic programmingMath	No attempts yet	1.5s	1024 MB	Judgeable
Lucky Number TestPrecompute the lucky numbers up to 1,000,000 by repeatedly sieving out elements at multiples of the current pick, then answer each query.	Medium5	ImplementationSimulation+2	No attempts yet	3s	1024 MB	Judgeable
Algorithm Class - Breadth First Search 4Run a BFS from vertex R with neighbors visited in ascending order, then sum depth times visit order over all vertices.	Medium5	BFSGraph+2	No attempts yet	1s	512 MB	Judgeable
CarpetOn a grid of white and black cells, move from top-left to bottom-right stepping only onto adjacent cells of the opposite color, and report the minimum number of moves or -1 if unreachable.	Medium5	BFSGraph+2	No attempts yet	2s	1024 MB	Judgeable
DebuggingGiven M error line numbers in N lines, find the most errors an editor can auto-fix after Ingyu manually fixes at least Y errors, where the editor triggers on any X consecutive clean lines.	Medium5	Two pointersSliding window+2	No attempts yet	0.6s	512 MB	Judgeable
Graph StemGiven a tree, repeatedly strip all leaves at once until two or fewer leaves remain, then output the surviving vertices in ascending order.	Medium5	TreeGraph+2	No attempts yet	1s	512 MB	Judgeable
MazeGiven a grid maze with two edge holes, the task is to mark every passage that is not on the shortest path between the holes with @.	Medium5	TreeDFS+1	No attempts yet	1s	512 MB	Judgeable
Feeding DuksuCount the length-N sequences over four restaurants plus a skip state where you never revisit today's restaurant or its neighbors tomorrow, and a skip forces eating the next day.	Medium5	Dynamic programmingCombinatorics+2	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Depth-First Search 6Run an iterative DFS from R visiting neighbors in descending order, record each vertex's depth and visit order, and sum depth times visit order over all vertices.	Medium5	DFSGraph+2	No attempts yet	1s	512 MB	Judgeable
Searching for SoulmatesFor each pair, find the fewest multiply by 2, divide by 2 (when even), or add 1 operations that turn the first personality into the second.	Medium5	MathGreedy	No attempts yet	1s	1024 MB	Judgeable
Non-Transitive DiceGiven two 4-sided dice with faces 1 to 10, decide whether a third 4-sided die can be built so the three dice beat each other in a cycle.	Medium5	Brute forceProbability+2	No attempts yet	1s	1024 MB	Judgeable
blobawwCount triples of cells forming the letters E, S, M in a grid so that both row and column indices are nondecreasing, modulo 1e9+7.	Medium5	Dynamic programmingPrefix sum+2	No attempts yet	2s	1024 MB	Judgeable
blobhyperthinkCount the strictly increasing subsequences of length 11 in sequence A, modulo 10^9+7.	Medium5	Dynamic programmingPrefix sum	No attempts yet	2s	1024 MB	Judgeable
queuestackEach of N positions is a queue or stack holding one value; insert M values one at a time and print the value that exits the end of the line.	Medium5	QueueStack+2	No attempts yet	1s	1024 MB	Judgeable
Card Game and QueriesGiven A, B, and K, decide who wins a card game where players add a card value from 1 to K to A until it reaches B or more.	Medium5	MathGame theory	No attempts yet	1s	1024 MB	Judgeable
Abridged ReadingGiven page counts and prerequisite edges forming a forest rooted at chapters with no dependents, find the two roots whose combined prerequisite closure has the smallest total page count.	Medium5	TreeDFS+2	No attempts yet	4s	1024 MB	Judgeable
Noonerized SpumbersGiven a false arithmetic equation x op y = z, swap proper prefixes of two of the three numbers to make the equation true.	Medium5	Brute forceString+2	No attempts yet	1s	1024 MB	Judgeable
RecyclingFind the contiguous range of weeks and bin capacity that maximize capacity times weeks, where every week in the range has at least that much material.	Medium5	StackArray	No attempts yet	2s	1024 MB	Judgeable
Bracket PairingGiven a bracket string of length up to 20 with some positions unknown, count how many ways to fill the unknowns so the whole sequence becomes a valid bracket sequence over four bracket types.	Medium5	Dynamic programmingString+2	No attempts yet	7s	1024 MB	Judgeable
Parking LotFind the shortest walk from the top-left to the bottom-right corner of a parking lot, where empty spots can be crossed diagonally and car spots only along their edges.	Medium5	Shortest pathGeometry+1	No attempts yet	5s	1024 MB	Judgeable