Problems

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Total results29,469 problems

Pizzas
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Snowball Fight
Easy3
Array, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cyclist
Easy3
Sorting, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Roller Coaster
Easy3
Simulation, Greedy
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Suffi\otimes
Easy3
Hash map, String
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Yoroshiku
Easy3
Probability, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Counting Sheep, Powers of A
Easy3
Math, Divide and conquer
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Let's Move!
Easy3
Geometry, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Converting Romans
Easy3
String, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Die Hard
Easy3
Brute force, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Palindrome Numbers
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Palindrome Anagram
Easy3
String, Hash map
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Seaweed is not a plant
Easy3
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Quadrat Survey (Easy)
Easy3
Array, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
A Sad Legend of Sejong and Yeongjae
Easy3
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Thomae's Function
Easy3
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cyclical Periods
Easy3
Hash map, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Don't Be Fake
Easy3
Prefix sum, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Boat Commuter
Easy3
Simulation, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Last One Standing
Easy3
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Naming Wine Bottles
Easy3
Hash map, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Natatorium
Easy3
Hash map, Number theory
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Middle of the Game
Easy3
Math, Implementation
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Progressive NoSQL
Easy3
Hash map, String
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Axis-Aligned Area
Easy3
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Missing Vowels
Easy3
String, Two pointers
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
A-maze-ing Lakes
Easy3
Matrix, BFS+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Course Prerequisites
Easy3
Hash map, String
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Port Robot
Easy3
Stack, String
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Finding a Home
Easy3
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bored Maru
Easy3
Intervals, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Score Management
Easy3
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sum of Consecutive Numbers
Easy3
Math, Number theory
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Twin Distribution Centers
Easy3
Graph, Union-find
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sparkling Stardust
Easy3
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Building a KOREA String
Easy3
String, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Temperature Adjustment
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Parking Payment
Easy3
Greedy, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bus Route Lengths
Easy3
Array, Two pointers
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Big Plans
Easy3
Array, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dungeons & Dragons
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Schedule
Easy3
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Watchmen
Easy3
Hash map, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Stars in a Regular Polygon
Easy3
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fibonacci Sum
Easy3
Brute force, Hash map
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Spoons
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Protecting the Fried Rice
Easy3
Geometry, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Yokohama Phenomena
Easy3
Brute force, Backtracking+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Snowflakes
Easy3
Matrix, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pingvin
Easy3
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Want to ensemble?
Easy3
Brute force, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
The Legend of Dakgangjeong
Easy3
Prefix sum, Matrix
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Padaeng Studies Hard as a Middle Schooler
Easy3
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
자동차 주차
Easy3
Combinatorics, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Swapped Distributive Law
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stock Simulation
Easy3
Simulation, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hit Song
Easy3
String, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The ABC Conjecture
Easy3
Brute force, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Warehouse
Easy3
Hash map, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hidden Password
Easy3
Math, String
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Decrease the Maximum
Easy3
Binary search, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Strange Shuffle Operation
Easy3
Math, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Super Prime
Easy3
Number theory, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Y
Easy3
Combinatorics, Graph
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Page Number
Easy3
String, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Chess Board
Easy3
Matrix, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Symmetric Numbers
Easy3
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mobile Ad Bidding
Easy3
Sorting, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Substrings Containing Letter a
Easy3
Math, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Symmetric String
Easy3
String, Two pointers
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Maximum Profit
Easy3
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Longest Force Protecting the Republic of Korea
Easy3
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Power
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Parking
Easy3
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pentagon
Easy3
Geometry, Dynamic programming
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Lines Per Hour
Easy3
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Magnesium Supplementation
Easy3
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Non-Shortest Path
Easy3
Backtracking, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
The First Day of School
Easy3
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Aris, Time to Clean! (Easy)
Easy3
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tree Explorer (Easy)
Easy3
Tree, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Duty Roster
Easy3
Hash map, Greedy
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Call forwarding chaos
Easy3
Graph, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Virtual Verification Technology
Easy3
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sponge
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
A+B - Two Step
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Not Prime 3
Easy3
Math, Number theory+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Sky and Pink
Easy3
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pigtail Pairing
Easy3
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Programming-trampoline-athlon!
Easy3
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
A Cappella Recording
Easy3
Sorting, Greedy
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Champernowne Verification
Easy3
String, Simulation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Four Die Rolls
Easy3
Brute force, Combinatorics
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Furiosa AI Video Processing Acceleration
Easy3
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hexagonal Tile Maze Escape
Easy3
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Online Assignment
Easy3
Brute force, Bit manipulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Dance
Easy3
Sorting, Greedy
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Maximizing Productivity
Easy3
Sorting, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Alien Math
Easy3
String, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Special Magic Attack
Easy3
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
PizzasGiven N riders, M showers, T minutes per shower, and a budget K, find the total pizza money left after each rider's shower-line wait is subtracted.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Snowball FightCount the friends Jonas can hit, where a snowball is blocked by any snowdrift between the two positions that is taller than the shorter of the two heights.	Easy3	ArrayBrute force	No attempts yet	1s	1024 MB	Judgeable
CyclistPick K distinct kilometers with the largest wetness values to ride by bus, so the total wetness left over is minimal.	Easy3	SortingGreedy	No attempts yet	1s	1024 MB	Judgeable
Roller CoasterGiven N groups of sizes a_i and a coaster that holds M people, print the earliest ride index (starting from 0) each group can board, keeping group order.	Easy3	SimulationGreedy	No attempts yet	2s	1024 MB	Judgeable
Suffi\otimesCount the suffixes that appear in an odd number of the N strings, since repeated XOR keeps only elements with odd multiplicity.	Easy3	Hash mapString	No attempts yet	0.5s	1024 MB	Judgeable
YoroshikuGiven department sizes and M, find the expected count of same-department pairs when M students are chosen uniformly at random, modulo 998244353.	Easy3	ProbabilityMath	No attempts yet	1s	1024 MB	Judgeable
Counting Sheep, Powers of AGiven A and B, find the sum 1 + A + A^2 + ... + A^(B-1) modulo 1,000,000,007, where B can be up to 10^12.	Easy3	MathDivide and conquer	No attempts yet	1s	1024 MB	Judgeable
Let's Move!Given N squares that may be rotated, find the most squares that one square fully contains, counting itself.	Easy3	GeometryBrute force	No attempts yet	1s	1024 MB	Judgeable
Converting RomansConvert each Roman numeral string to its integer value, where any digit left of a larger digit is subtracted.	Easy3	StringSimulation	No attempts yet	1s	1024 MB	Judgeable
Die HardGiven three six-sided dice, find the smallest die John can pick that wins at least half the time against either die Hans might choose, or report No dice.	Easy3	Brute forceImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Palindrome NumbersGiven n below 10^10, count the palindrome numbers from 1 to n inclusive.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Palindrome AnagramDecide whether swaps between the left and right halves can turn a string into a palindrome, given that the middle character stays fixed for odd N.	Easy3	StringHash map	No attempts yet	1s	1024 MB	Judgeable
Seaweed is not a plantGiven recorded photosynthesis and motility test results for N organisms, find the minimum and maximum possible number of plants.	Easy3	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Quadrat Survey (Easy)Given N flower kinds in a row, answer how many flowers of a given kind lie in a range, and remove all flowers in a range on request.	Easy3	ArraySimulation	No attempts yet	1s	1024 MB	Judgeable
A Sad Legend of Sejong and YeongjaeAssign each of the N bags to a different day so that every day receives at least its minimum A_i, or report -1 if no assignment exists.	Easy3	GreedySorting	No attempts yet	1s	1024 MB	Judgeable
Thomae's FunctionGiven P and Q, count the real numbers x in [0, 1] whose Thomae function value f(x) is at least P/Q.	Easy3	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
Cyclical PeriodsGiven letter strings at sparse positions on a number line, find the letter whose periodic occurrences have the longest period.	Easy3	Hash mapMath+1	No attempts yet	1s	1024 MB	Judgeable
Don't Be FakeGiven each friend's available second intervals, find the maximum number of friends who can photograph one notification second and count the seconds that reach it.	Easy3	Prefix sumArray	No attempts yet	1s	1024 MB	Judgeable
Boat CommuterGiven a chronological log of pier tap events, compute each travel card's total fare, where an unfinished trip or a trip starting and ending at the same pier costs 100 pounds.	Easy3	SimulationArray	No attempts yet	2s	1024 MB	Judgeable
Last One StandingTwo units fire missiles at fixed reload intervals with a 0.5 second delay; find which player's unit is destroyed first, or whether both fall at the same moment.	Easy3	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Naming Wine BottlesGive each bottle volume a lowercase Latin name, using the same name for equal volumes that have up to 10 decimal digits in liters.	Easy3	Hash mapString+1	No attempts yet	2s	1024 MB	Judgeable
NatatoriumGiven an area C that is the product of two distinct primes, find the two listed primes whose product is C and print them in increasing order.	Easy3	Hash mapNumber theory	No attempts yet	2s	1024 MB	Judgeable
Middle of the GameGiven Alice's and Bob's points after some tic-tac-toe rounds, find the number of wins and draws, or print Error if the scores are impossible or Undefined if the answer is not unique.	Easy3	MathImplementation	No attempts yet	0.5s	1024 MB	Judgeable
Progressive NoSQLGiven Q registration requests, each name is assigned as-is if free, otherwise the smallest suffix number (1, 2, ...) that makes it unused is appended.	Easy3	Hash mapString	No attempts yet	2s	1024 MB	Judgeable
Axis-Aligned AreaGiven four sorted stick lengths, find the largest area of an axis-aligned rectangle the sticks can enclose.	Easy3	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Missing VowelsCheck whether the short name s can be formed from the full name f by deleting only vowels (a, e, i, o, u, y), ignoring letter case.	Easy3	StringTwo pointers	No attempts yet	2s	1024 MB	Judgeable
A-maze-ing LakesGiven a binary grid, count the 4-connected components of water tiles and report each component's size in sorted order.	Easy3	MatrixBFS+1	No attempts yet	10s	1024 MB	Judgeable
Course PrerequisitesChecks whether every course in set B also appears in set A, printing 1 if so and 0 otherwise.	Easy3	Hash mapString	No attempts yet	5s	1024 MB	Judgeable
Port RobotGiven a log where lowercase letters store containers and uppercase letters remove them, decide whether each removal takes the top container and storage ends empty.	Easy3	StackString	No attempts yet	10s	1024 MB	Judgeable
Finding a HomeFor each query L R, people L to R may swap houses among themselves. Print the sequence that maximizes the sum of house index times person number.	Easy3	GreedySorting+1	No attempts yet	1s	1024 MB	Judgeable
Bored MaruEach order covers a circular arc of 2b degrees centered opposite the wall point at angle a. Count the integer sensors hit by at least one arc.	Easy3	IntervalsPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Score ManagementRank participants by score with shared ranks for ties, then print the rank, name, and score of each non-hidden participant sorted by rank and then name.	Easy3	SortingImplementation	No attempts yet	1s	1024 MB	Judgeable
Sum of Consecutive NumbersFor each integer n until 0, decide whether n is a sum of two or more consecutive positive integers, printing SIM or NAO.	Easy3	MathNumber theory	No attempts yet	0.5s	1024 MB	Judgeable
Twin Distribution CentersGiven undirected city links for several test cases, count the pairs of cities that fall in the same connected component.	Easy3	GraphUnion-find	No attempts yet	2s	1024 MB	Judgeable
Sparkling StardustGiven a day-by-day plan of spell casts and rests, compute the total stardust made with combo and skill bonuses, or -1 if fatigue breaks the wand.	Easy3	SimulationImplementation	No attempts yet	1s	512 MB	Judgeable
Building a KOREA StringGiven a string of the letters K, O, R, E, A, find the length of the longest subsequence that spells KOREA repeatedly, starting with K.	Easy3	StringDynamic programming	No attempts yet	1s	1024 MB	Judgeable
Temperature AdjustmentFind the fewest presses so every beaker reaches its target when each press shifts beaker i by plus or minus X_i, or print -1 if no press count works.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Parking PaymentGiven three pass prices for 1, 7, and 28 days and a number of days n, find the minimum cost to cover all n days.	Easy3	GreedyMath+1	No attempts yet	2s	1024 MB	Judgeable
Bus Route LengthsGiven k and a binary string marking villages, find for each village the distance to the village k positions to its right, or to the last village.	Easy3	ArrayTwo pointers	No attempts yet	2s	1024 MB	Judgeable
Big PlansGiven n planned trips inside a visa of a days, the task is to check whether every b consecutive days contain at most c days spent in the Schengen area.	Easy3	ArrayPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Dungeons & DragonsCount the pairs (x, y) where x is in [a, b], y is in [c, d], and x + y equals n.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
ScheduleGiven a year, the weekday of January 1, and a list of public holidays, find the day off that gives the most days off and the one that gives the fewest.	Easy3	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
WatchmenCount pairs of points whose Manhattan distance equals their Euclidean distance, given n points with integer coordinates.	Easy3	Hash mapMath	No attempts yet	2s	1024 MB	Judgeable
Stars in a Regular PolygonGiven the vertex count N of a regular polygon, count the distinct stars that can be drawn by connecting its vertices.	Easy3	MathCombinatorics	No attempts yet	1s	1024 MB	Judgeable
Fibonacci SumGiven k and x, decide whether x equals the sum of exactly k Fibonacci numbers, where the same term may be reused.	Easy3	Brute forceHash map	No attempts yet	1s	1024 MB	Judgeable
SpoonsGiven Petya's carving speed A and painting speed B in spoons per day, find the maximum number of spoons he can paint in one day.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Protecting the Fried RiceFind the integer wok center (X, Y) that covers the most grains within distance R, given N distinct integer grain positions.	Easy3	GeometryBrute force	No attempts yet	1s	1024 MB	Judgeable
Yokohama PhenomenaCount the paths of eight cells, each adjacent to the previous one, whose letters spell Y, O, K, O, H, A, M, A in order on the grid.	Easy3	Brute forceBacktracking+1	No attempts yet	2s	1024 MB	Judgeable
SnowflakesGiven a grid of snowflake characters, find the largest size, where each snowflake's size is the shortest arm among its eight directions from the center.	Easy3	MatrixImplementation+1	No attempts yet	1s	1024 MB	Judgeable
PingvinFind the fewest unit moves along the x, y, or z axis needed to fly from the start cell to the end cell through cloud-free cells in an n by n by n cube.	Easy3	BFSGraph+1	No attempts yet	1s	1024 MB	Judgeable
Want to ensemble?Given predictions from N models on M items, check whether some odd-sized group of models, combined by majority vote, beats the most accurate single model.	Easy3	Brute forceBit manipulation	No attempts yet	1s	512 MB	Judgeable
The Legend of DakgangjeongGiven an N by N grid, answer Q rectangle queries by summing interior cells as +1 and border cells as -1.	Easy3	Prefix sumMatrix	No attempts yet	4s	512 MB	Judgeable
Padaeng Studies Hard as a Middle SchoolerGiven a paper of 3x8 cells, each holding an addition equation a+b=c, mark the margin of correct equations with stars and wrong ones with slashes.	Easy3	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
자동차 주차Count the distinct ways to arrange A red, B green, and C blue cars in N parking spaces, where cars of the same color are indistinguishable.	Easy3	CombinatoricsMath	No attempts yet	1s	1024 MB	Judgeable
Swapped Distributive LawCount integer triples (a, b, c) with absolute values at most N that satisfy a + bc = (a + b)(a + c).	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Stock SimulationSimulate buying, selling, and price changes across companies grouped by number, then print the cash and total liquidation value at each menu 6 or 7 query.	Easy3	SimulationHash map+1	No attempts yet	1s	1024 MB	Judgeable
Hit SongGiven pleasant words and song lyrics, decide per test case whether at least 75% of the lyric words (case-insensitive) are pleasant.	Easy3	StringHash map+1	No attempts yet	1s	1024 MB	Judgeable
The ABC ConjectureFor each range [L, H], list every coprime equation a + b = c whose radical d of a·b·c is smaller than c, sorted by c then a.	Easy3	Brute forceNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
WarehouseSum each toy's count across all shipments, then list the toys by count in decreasing order, breaking ties alphabetically.	Easy3	Hash mapSorting	No attempts yet	1s	1024 MB	Judgeable
Hidden PasswordGiven the first password, find the second one, which is a Caesar-cipher encoding with an unknown positive key d, or print NIE if it cannot be determined.	Easy3	MathString	No attempts yet	3s	1024 MB	Judgeable
Decrease the MaximumGiven five integers and at most k decrements of 1 each, find the smallest possible value of the largest number after the operations.	Easy3	Binary searchGreedy	No attempts yet	1s	1024 MB	Judgeable
Strange Shuffle OperationGiven n, apply the swaps of B_k and B_lowbit(k) for k from 1 to n to the identity sequence, then report the index where the value 1 ends up.	Easy3	MathSimulation	No attempts yet	1s	1024 MB	Judgeable
Super PrimeGiven n, print the n-th super prime, where a super prime is a prime whose index among all primes is also prime. Up to 1000 queries with n up to 3000.	Easy3	Number theorySorting	No attempts yet	1s	1024 MB	Judgeable
YCount the Y shapes in an undirected graph, where a root vertex has three edges to three leaves, modulo 10^9+7.	Easy3	CombinatoricsGraph	No attempts yet	1s	1024 MB	Judgeable
Page NumberCount the ways to split a digit string into two numbers i and n with no leading zeros and 1 <= i <= n.	Easy3	StringBrute force	No attempts yet	1s	1024 MB	Judgeable
Chess BoardGiven a 4 by 5 grid filled with 1 to 20, find the largest k such that each number from 1 to k is a knight move away from the previous one.	Easy3	MatrixSimulation	No attempts yet	1s	1024 MB	Judgeable
Symmetric NumbersGiven the first three digits A, B, and C, print the smallest symmetric number that starts with them.	Easy3	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Mobile Ad BiddingFind the smallest nonnegative integer X so that adding X to every bid A_i makes A_i + X at least B_i in at least K slots.	Easy3	SortingArray	No attempts yet	2s	1024 MB	Judgeable
Substrings Containing Letter aGiven the length n and the positions p and q of the two letter a's in a string, count the substrings containing at least one a, modulo 123456789.	Easy3	MathString+1	No attempts yet	1s	1024 MB	Judgeable
Symmetric StringGiven a string, find the fewest characters to append to its end so that it becomes a palindrome, and print those characters.	Easy3	StringTwo pointers	No attempts yet	1s	1024 MB	Judgeable
Maximum ProfitGiven processor and monitor prices, pair them into the most systems possible and find the maximum total of the price products.	Easy3	GreedySorting	No attempts yet	1s	1024 MB	Judgeable
The Longest Force Protecting the Republic of KoreaGiven a digit string, split it into the fewest pieces where each piece is a number from 1 to 641 without leading zeros.	Easy3	Dynamic programmingString	No attempts yet	1s	1024 MB	Judgeable
PowerFor each column j, raise the first-row value a_j to the power j+1, add all these diagonal powers, and print the sum modulo m.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
ParkingCount the legal parking spaces on each street plan, skipping garages, bus stops with the 10 m before them, and crossings with 5 m on each side.	Easy3	ImplementationSimulation+1	No attempts yet	1s	1024 MB	Judgeable
PentagonGiven up to 10,000 pentagons by their vertex coordinates, count the triangulations of each one, where every pentagon has 5 possible diagonal sets with at most 5 triangulations per shape.	Easy3	GeometryDynamic programming	No attempts yet	2s	1024 MB	Judgeable
Lines Per HourGiven each problem's line count and a team's lines-per-hour limit, find the largest set of problems whose total lines fit in five hours.	Easy3	GreedySorting	No attempts yet	1s	1024 MB	Judgeable
Magnesium SupplementationGiven n, k, and p, list every pill dosage d up to k that divides n, where n divided by d is at most p.	Easy3	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
Non-Shortest PathGiven a 4x4 grid with walls, find one simple path from the top-left to the bottom-right cell that is longer than the shortest path, or print -1.	Easy3	BacktrackingDFS+1	No attempts yet	2s	1024 MB	Judgeable
The First Day of SchoolGiven up to 12 courses, each with a name and a Tuesday, Thursday, or Saturday slot from 1 to 4, print a 4 by 3 timetable table with word-wrapped names.	Easy3	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Aris, Time to Clean! (Easy)Simulate a robot that cleans dust on an H by W grid using two rule tables, and count the moves until it leaves the room or can no longer remove dust.	Easy3	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Tree Explorer (Easy)Given a folder tree where folders can be expanded or collapsed, move a cursor over the visible list and print the folder under it after each move.	Easy3	TreeDFS+1	No attempts yet	1s	1024 MB	Judgeable
Duty RosterGiven N duty days with soldier numbers, decide whether the roster can be rearranged so no soldier is on duty on two consecutive days.	Easy3	Hash mapGreedy	No attempts yet	0.5s	1024 MB	Judgeable
Call forwarding chaosGiven each phone's forwarding target, change the fewest settings so that every phone's call ends in a loop of two or more phones, and print the new settings.	Easy3	GraphImplementation	No attempts yet	1s	1024 MB	Judgeable
Virtual Verification TechnologyTwo researchers split simulations for models A and B, and only the senior can run B, so find the minimum time to finish all of them.	Easy3	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
SpongeGiven K labeled viruses on a W by H grid that each move one king step or stay each second, count the distinct placements possible after T seconds modulo 998244353.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
A+B - Two StepGiven A and B, output a 13-letter lowercase string from which the sum A+B can be recovered, then compute A+B from that string alone.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Not Prime 3Given a set of usable digits, find a non-prime number up to 10^12 made only from those digits, or report that none exists.	Easy3	MathNumber theory+1	No attempts yet	0.5s	1024 MB	Judgeable
Sky and PinkGiven two lists of positive integers, find nonzero a and b with absolute value at most 1000000 that make \|a·sum(A) - b·sum(B)\| as small as possible.	Easy3	MathNumber theory	No attempts yet	1s	1024 MB	Judgeable
Pigtail PairingCount the ways to split N labeled guests into pairs for two-person tables, where seat order and table order do not matter.	Easy3	MathCombinatorics+1	No attempts yet	1s	1024 MB	Judgeable
Programming-trampoline-athlon!Given each team's solved problem count and six trampoline scores, compute totals and list the teams with at most two teams scoring strictly higher.	Easy3	SortingImplementation	No attempts yet	1s	1024 MB	Judgeable
A Cappella RecordingGiven n pitches and a maximum allowed range d, find the fewest recordings so that each recording's max minus min pitch is at most d and every note is covered.	Easy3	SortingGreedy	No attempts yet	1s	2048 MB	Judgeable
Champernowne VerificationGiven n, check whether its digits equal the concatenation of 1, 2, ..., k for some k, and output k or -1.	Easy3	StringSimulation	No attempts yet	1s	2048 MB	Judgeable
Four Die RollsGiven the first 1 to 3 die rolls, count the ways to finish four rolls with all digits distinct (Ashley wins) and with a repeated digit (Brandon wins).	Easy3	Brute forceCombinatorics	No attempts yet	1s	2048 MB	Judgeable
Furiosa AI Video Processing AccelerationGiven speedup a and job times m and n, find the minimum time to finish two jobs when one computer is upgraded and each computer runs one job at a time.	Easy3	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
Hexagonal Tile Maze EscapeFind the shortest path from (0,0) to (N-1, M-1) on a hex grid avoiding obstacles, and print its tile count or -1.	Easy3	BFSGraph+1	No attempts yet	1s	1024 MB	Judgeable
Online AssignmentFind the true or false answers to five questions by submitting full answer sets, using the number of correct answers from each rejected submission as feedback.	Easy3	Brute forceBit manipulation	No attempts yet	2s	1024 MB	Judgeable
DanceGiven the heights of 2N students, decide whether they can be split into N pairs where each pair's height difference is at most D.	Easy3	SortingGreedy	No attempts yet	2s	1024 MB	Judgeable
Maximizing ProductivityFor each query with wake-up time S and target V, report whether at least V farms satisfy S + t_i < c_i.	Easy3	SortingBinary search+1	No attempts yet	2s	1024 MB	Judgeable
Alien MathGiven B alien digit strings and an alien number X, print X's decimal value. The digit strings are prefix-free, so X splits into digits in only one way.	Easy3	StringHash map+1	No attempts yet	1s	1024 MB	Judgeable
Special Magic AttackFind the minimum total energy to punish students in a line so that every pair of adjacent students has at least one punished.	Easy3	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable