Interview warm-up

Short whiteboard warmups

Under construction

Still being built. Things may change

Total results4,880 problems

XO
Easy2
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Curling
Easy2
Implementation, Math
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Square
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Zero
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Time Limits
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bomb
Easy2
Matrix, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Growth Potion Selection Ticket
Easy2
Implementation, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Choosing Problems
Easy2
Hash map, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
A+B
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Alternating word
Easy2
String, Greedy
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Kent-buggen
Easy2
Hash map, String
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
The Train Switch
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Viking Hackers
Easy2
Hash map, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Chocolate Box
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pyramid Construction
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Refrigerator Transport
Easy2
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Morning Exercises
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
ISBN
Easy2
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Vertical Histogram
Easy2
Array, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Making Change
Easy2
Greedy, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Special Chicken Distribution
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ice Cream
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Halli Galli
Easy2
Implementation, Hash map
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Adjacent Colors
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Old English
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
FHL Final
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
PE Class
Easy2
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Three-Legged Race
Easy2
Array, Hash map
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Score
Easy2
Simulation, Hash map
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
JOI Editor
Easy2
String, Simulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Estimathon
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Class Field Trip
Easy2
Sorting, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ghost Leg
Easy2
Simulation, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Honeycomb 2
Easy2
Math, Implementation
No attempts yet
Time limit
0.25s
Memory limit
1024 MB
Judgeable
Non-Prime Number
Easy2
Math, Implementation
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Hotelier
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Absolute Difference Sequence
Easy2
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hunt the Wumpus
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Splitology
Easy2
String, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Vestigium
Easy2
Array, Implementation
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Encrypted School Name
Easy2
Implementation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
SciComLove (2023)
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Clothes Hangers
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Orange Eaten Long Ago
Easy2
Brute force, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cube pile
Easy2
Implementation, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ribbon (Easy)
Easy2
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Daily Trips
Easy2
Simulation, Implementation
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
Lemon Picking
Easy2
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Naming the Team
Easy2
Implementation, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Cream Bread
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Flower Festival
Easy2
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
The Informatics Teacher's Ambition
Easy2
Brute force, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hungry (Easy)
Easy2
Bit manipulation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Three-Tier Chocolate Ice Cream
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stack 2
Easy2
Stack, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Gift
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
in-out? out-in? stairs? reverse?
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
10!
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Egypt
Easy2
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Skateboard
Easy2
Implementation, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Word Chain
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Colorful Parrots
Easy2
Implementation, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Potato
Easy2
Sorting, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Slip~Hit! Hit~Slip!
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Piltover and Zaun
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Super Lucky Tickets (Basic)
Easy2
Brute force, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Lunch Break
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Marmalade Recipe
Easy2
Prefix sum, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Gravity Falls Diary
Easy2
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Doctor Strange and the Swap
Easy2
Implementation, Brute force+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Journey Through Worlds
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Amulet Split
Easy2
Math, Geometry
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Final Grade
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Spaceship
Easy2
Array, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Figurines
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Almost Favorite Numbers
Easy2
Math, Implementation
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Just Laughter
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Time to Rest
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Guards
Easy2
Brute force, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
The Case of the Game
Easy2
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Filter
Easy2
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Football
Easy2
Brute force, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Distributing the Rings of Power
Easy2
Greedy
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Treasure Map
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Squad
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Harry Potter and Voldemort's Nose
Easy2
Implementation, Matrix
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Gasoline Production
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Strange Grasshopper
Easy2
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Chess
Easy2
Implementation, Simulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sandwich Preparation
Easy2
Implementation, Brute force
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sequence
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Curling
Easy2
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Radio-Controlled Car Race
Easy2
Brute force, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Time Standards
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Real Number
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Beusil's Ttibu-Ttibu Sticker Collection
Easy2
Hash map, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Problems No Larger Than the Weeds
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
So, how many problems have you solved?
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
What Is in the Apple Box? Cash?
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dynamic Array
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
XOGiven the first N moves of a tic-tac-toe game, decide whether X or O moves next, whether X or O has won, or whether the game is a draw.	Easy2	ImplementationSimulation	No attempts yet	1s	1024 MB	Judgeable
CurlingCount each team's stones that touch the house and are closer to the center than every opposing stone that also touches it.	Easy2	ImplementationMath	No attempts yet	20s	1024 MB	Judgeable
SquareGiven words, print a square where each row is the word cyclically shifted one more position than the row above it.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
ZeroGiven a zero-free integer k, find the next positive integer after k that also contains no zero digit.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Time LimitsFor each dataset, find the smallest whole-second time limit that is at least s times the slowest model solution's time in milliseconds.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
BombGiven a grid of walls, empty cells, and enemies, find the empty cell where a bomb destroys the most enemies along four directions, stopped by walls.	Easy2	MatrixSimulation	No attempts yet	1s	1024 MB	Judgeable
Growth Potion Selection TicketGiven a character level from 200 to 239, the task is to pick the Growth Potion that lets the character reach the highest level, with ties going to the lower potion.	Easy2	ImplementationBrute force	No attempts yet	1s	1024 MB	Judgeable
Choosing ProblemsGiven the slot each idea fits, decide whether every one of the fifteen slots can be filled, with slots 5A, 5B, and 5C each needing two problems.	Easy2	Hash mapImplementation	No attempts yet	1s	1024 MB	Judgeable
A+BGiven two positive integers a and b with at most 5000 digits each, print their sum.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Alternating wordGiven a string, find the fewest letters to delete so that no two adjacent remaining letters are equal.	Easy2	StringGreedy	No attempts yet	4s	1024 MB	Judgeable
Kent-buggenGiven n artist names, count how many distinct names appear more than once.	Easy2	Hash mapString	No attempts yet	6s	1024 MB	Judgeable
The Train SwitchCount how many times the station master must flip a track switch over one day, given two trains that depart every n and m minutes.	Easy2	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Viking HackersSplit a binary string into 4-bit chunks, map each chunk to its character using a lookup table, and print ? for chunks with no match.	Easy2	Hash mapString	No attempts yet	1s	1024 MB	Judgeable
Chocolate BoxCount how many times the piece count rises between consecutive observations, since each rise means a new box was bought.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Pyramid ConstructionGiven N blocks, find the largest height h whose layers 1^2 + 3^2 + ... + (2h-1)^2 use at most N blocks.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Refrigerator TransportGiven two cars with a per-trip cost and a capacity each, find the trip counts for each car that move n refrigerators at the lowest total cost.	Easy2	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
Morning ExercisesGiven a 2 x N pasture with some tree squares, find the longest run of tree-free columns and print twice its length.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
ISBNGiven a 10-character ISBN with one '?', find the digit (0 to 9 or X) that makes the weighted sum divisible by 11, or print -1 if none does.	Easy2	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
Vertical HistogramCount how many times each capital letter appears in four input lines and print a vertical asterisk histogram with the alphabet below.	Easy2	ArrayImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Making ChangeGiven a purchase price P in cents, output the fewest 25, 10, 5, and 1 cent coins that make change for one dollar.	Easy2	GreedyMath	No attempts yet	1s	1024 MB	Judgeable
Special Chicken DistributionGiven N pieces of each of three chicken kinds and soldier preference counts A, B, C, find the maximum number of soldiers who get their preferred chicken.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Ice CreamGiven N serial numbers, find the length of the longest contiguous run of even numbers in the sequence.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Halli GalliGiven the revealed cards, decide whether any single fruit kind totals exactly 5 across all cards so Hanbyeol should ring the bell.	Easy2	ImplementationHash map	No attempts yet	1s	1024 MB	Judgeable
Adjacent ColorsFor each circular string of R, G, and B beads, find the color pair that is adjacent most often, printing every pair that ties for the maximum.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Old EnglishTranslate each word by replacing s, a leading e, and oo according to three rules while keeping the case of the first letter.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
FHL FinalGiven the results of a best-of-n series of k games, find the earliest game after which the winner is known and mark which games were predictable.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
PE ClassStudents are sorted by height within each sex group, boys first, and the task is to find the largest height gap between neighbors in the row.	Easy2	SortingImplementation	No attempts yet	1s	1024 MB	Judgeable
Three-Legged RaceGiven the team numbers of the first 2N-1 students, find the team of student 2N, which is the only team that appears once.	Easy2	ArrayHash map	No attempts yet	2s	1024 MB	Judgeable
ScoreSimulate a score that adds A_i each round and resets to 0 whenever it equals a value in B, then print the final score.	Easy2	SimulationHash map	No attempts yet	2s	1024 MB	Judgeable
JOI EditorGiven a sequence of j, o, and i key presses, the task is to output the final text after each adjacent pair of identical lowercase letters becomes uppercase.	Easy2	StringSimulation	No attempts yet	2s	1024 MB	Judgeable
EstimathonGiven the chair count of each colour, decide whether every colour can fill whole tables of four chairs so that exactly n tables are filled.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Class Field TripGiven two sorted lowercase strings, print one string that contains all their letters in alphabetical order.	Easy2	SortingString	No attempts yet	1s	1024 MB	Judgeable
Ghost LegSimulate a Ghost Leg with n vertical lines and m horizontal lines from top to bottom, then print the resulting order of the elements.	Easy2	SimulationArray	No attempts yet	1s	1024 MB	Judgeable
Honeycomb 2Given room number N in a hexagonal honeycomb numbered outward from center room 1, find how many rooms lie on the shortest path from room 1 to room N, counting both ends.	Easy2	MathImplementation	No attempts yet	0.25s	1024 MB	Judgeable
Non-Prime NumberGiven N, print any integer at least N that is not prime. The answer must be at most 10^9.	Easy2	MathImplementation	No attempts yet	0.5s	1024 MB	Judgeable
HotelierSimulate customers entering a 10-room hotel from the left or right end and leaving by room number, then print which rooms are occupied at the end.	Easy2	SimulationImplementation	No attempts yet	1s	256 MB	Judgeable
Absolute Difference SequenceRepeatedly replace a sequence with the absolute differences of its adjacent terms until one value remains, then print that value.	Easy2	SimulationImplementation	No attempts yet	2s	1024 MB	Judgeable
Hunt the WumpusGiven a seeded generator that places four wumpuses on a 10x10 grid, report each guess's hit status and the Manhattan distance to the nearest remaining wumpus.	Easy2	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
SplitologyGiven a lowercase string of length up to 500, find a split into two non-empty palindromes, or report NO if none exists.	Easy2	StringBrute force	No attempts yet	1s	1024 MB	Judgeable
VestigiumGiven an N by N matrix with values from 1 to N, find its trace and count the rows and columns that contain a repeated value.	Easy2	ArrayImplementation	No attempts yet	20s	1024 MB	Judgeable
Encrypted School NameGiven an encrypted school name, find which of four schools it came from by trying all 26 possible shifts of its processed name.	Easy2	ImplementationBrute force+1	No attempts yet	1s	512 MB	Judgeable
SciComLove (2023)Given the prefix of length N of the repeated string SciComLove, flip the case of one character per query and print the uppercase count after each query.	Easy2	ArrayImplementation	No attempts yet	2s	1024 MB	Judgeable
Clothes HangersGiven each hanger's type and the counts of tops and bottoms, decide whether all clothes can be hung and print one valid assignment if so.	Easy2	ImplementationMath	No attempts yet	1s	256 MB	Judgeable
Orange Eaten Long AgoGiven a string, decide whether some length L makes the prefix of length L and the suffix of length L differ in exactly one position.	Easy2	Brute forceString	No attempts yet	1s	1024 MB	Judgeable
Cube pileCount the cubes whose six face-adjacent positions all contain cubes in an N by N by N grid.	Easy2	ImplementationArray	No attempts yet	1s	1024 MB	Judgeable
Ribbon (Easy)Given N ribbons with positions, lengths, and colors, find two ribbons of different colors that can be tied together, or report NO.	Easy2	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
Daily TripsSimulate Bella's umbrella rule over N days and output, for each of the 2N bus trips, whether she carries an umbrella.	Easy2	SimulationImplementation	No attempts yet	0.1s	1024 MB	Judgeable
Lemon PickingSeongwoo picks lemons from one tree and walks home, losing one lemon per move. Find the maximum number of lemons he can carry home.	Easy2	ImplementationMath	No attempts yet	2s	1024 MB	Judgeable
Naming the TeamGiven three members' solved counts, admission years, and surnames, print a name from the years mod 100 sorted ascending and another from surname initials sorted by solved count.	Easy2	ImplementationSorting+1	No attempts yet	2s	1024 MB	Judgeable
Cream BreadCount the groups of K consecutive loaves where the number of loaves without cream (0) is fewer than P.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Flower FestivalGiven each car's position and constant speed on a road of length f, find the number of the car that reaches the end first.	Easy2	ImplementationMath	No attempts yet	2s	1024 MB	Judgeable
The Informatics Teacher's AmbitionPick two of the five weekdays so that the most students can attend both lecture days, then print that count and the chosen schedule.	Easy2	Brute forceImplementation	No attempts yet	2s	1024 MB	Judgeable
Hungry (Easy)For each positive integer m, print the pair x and y (x <= y) where 2^x + 2^y = m.	Easy2	Bit manipulationMath	No attempts yet	1s	1024 MB	Judgeable
Three-Tier Chocolate Ice CreamGiven uppercase strings, decide whether each one matches one of four three-part patterns built from a prefix of length ceil(n/3) and its reverse.	Easy2	ImplementationString+1	No attempts yet	1s	1024 MB	Judgeable
Stack 2Process N stack commands that push integers, pop or peek the top value, report the size, and check emptiness, printing -1 when the stack is empty.	Easy2	StackImplementation	No attempts yet	2s	1024 MB	Judgeable
GiftGiven the daily sock prices, find the minimum cost to buy X socks on each of two consecutive days, 2X socks in total.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
in-out? out-in? stairs? reverse?Given a string that is a permutation of the eight keys a s d f j k l ;, decide whether it is in-out, out-in, stairs, reverse, or none of these.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
10!Given N from 10 to 17, print how many weeks N! seconds equals, using 6 weeks as 3628800 seconds.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
EgyptStarting from P, follow the connected chain of x cells in a grid and print the direction of each move (gore, dolje, lijevo, desno), one per line.	Easy2	ImplementationSimulation	No attempts yet	1s	1024 MB	Judgeable
SkateboardGiven each athlete's two run scores and five trick scores, find the highest final score, where each final score is the best run plus the top two tricks.	Easy2	ImplementationSorting	No attempts yet	1s	1024 MB	Judgeable
Word ChainGiven a word chain record with one hidden word and a list of candidates, find the candidate that makes the chain valid with no repeated words.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Colorful ParrotsGiven the body and tail colors of two parrots, list every distinct body and tail color pair a chick can have, sorted in dictionary order.	Easy2	ImplementationSorting+1	No attempts yet	1s	1024 MB	Judgeable
PotatoPark and Sungwoo take turns grabbing whole plates of fries, Park first, and the task is to find each player's total under optimal play.	Easy2	SortingGreedy	No attempts yet	1s	1024 MB	Judgeable
Slip~Hit! Hit~Slip!Given N moves with attack and dodge gains and real multipliers K_i, find the maximum final adrenaline when every move starts with the same action type.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Piltover and ZaunGiven current statuses x1 and x2 and n years, decide whether Piltover gaining and Zaun losing the same yearly amounts can produce them.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Super Lucky Tickets (Basic)Count the digit tickets of length n where the first half and second half have equal digit sums, and even-position and odd-position digit sums are also equal.	Easy2	Brute forceImplementation	No attempts yet	2s	1024 MB	Judgeable
Lunch BreakFor each restaurant, add the distance from the hideout, the eating time, and the distance to the destination, then output the smallest total.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Marmalade RecipeGiven cumulative counts b_i of values at most i, rebuild the sorted array a of n integers from 1 to m.	Easy2	Prefix sumImplementation	No attempts yet	2s	1024 MB	Judgeable
Gravity Falls DiaryGiven page size, letter size, and letter count, find how many pages the diary needs, or -1 if no letter fits on a page.	Easy2	ImplementationMath	No attempts yet	2s	1024 MB	Judgeable
Doctor Strange and the SwapFind two positions whose swap puts even numbers on even positions and odd numbers on odd positions, or report -1 -1 if no swap works.	Easy2	ImplementationBrute force+1	No attempts yet	2s	1024 MB	Judgeable
Journey Through WorldsCount the repdigit numbers (such as 11, 222, or 9999) between l and r, where l and r can be as large as 10^18.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Amulet SplitGiven a right triangle with legs X and Y on the axes, find the vertical line x that splits its area into two equal halves.	Easy2	MathGeometry	No attempts yet	2s	1024 MB	Judgeable
Final GradeGiven a string of letter grades (A is best, Z worst), output the mean rounded in the student's favor, capped at one step better than the worst grade.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
SpaceshipGiven n enemy strengths, find the boss, which equals the sum of the others, and print the order that destroys it last.	Easy2	ArrayMath	No attempts yet	2s	1024 MB	Judgeable
FigurinesGiven n figurines each facing N, S, W, or E, find the fewest turns needed to make all of them face the same direction.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Almost Favorite NumbersCount the integers from 1 to m whose decimal representation ends with the digits of n.	Easy2	MathImplementation	No attempts yet	0.5s	1024 MB	Judgeable
Just LaughterFind the length of the longest substring made of alternating letters a and h in a string of up to 100,000 lowercase letters.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Time to RestGiven n penguin groups with start a_i, step b_i, and size c_i, find the total count of penguins whose path passes through point k.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
GuardsCount the guards in an n by m grid whose Manhattan distance to the ship at (x, y) is at most k, excluding the ship's own cell.	Easy2	Brute forceImplementation	No attempts yet	2s	1024 MB	Judgeable
The Case of the GameTrack the ammo count through save, load, shoot, and ammo actions, and print the count after each action.	Easy2	SimulationImplementation	No attempts yet	2s	1024 MB	Judgeable
FilterSimulate n daily oil pours into a filter of capacity r that drains x liters per day, and find the total oil that flows out.	Easy2	SimulationImplementation	No attempts yet	2s	1024 MB	Judgeable
FootballFor each first-leg score a:b, count the second-leg results where LAG wins and where DCU wins, by total goals and then away goals.	Easy2	Brute forceImplementation	No attempts yet	2s	1024 MB	Judgeable
Distributing the Rings of PowerGiven sizes of ring groups, find the fewest rings that must be handed out one by one until only one group remains.	Easy2	Greedy	No attempts yet	2s	1024 MB	Judgeable
Treasure MapEach clue bounds the treasure with a strict inequality, so count the lattice points inside the resulting rectangle, or print Infinity if some side is open.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
SquadGiven two equal-length digit strings a and b, print the string that takes the larger digit at each position.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Harry Potter and Voldemort's NoseCount the pairs of horizontally or vertically adjacent free cells in an n by m grid, where each pair can hold the nose.	Easy2	ImplementationMatrix	No attempts yet	2s	1024 MB	Judgeable
Gasoline ProductionGiven n bids with line cost A, per-ton cost B, and price C, find the bid index that minimizes A/(C-B), with ties going to the smallest index.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Strange GrasshopperStarting at stone 1, the grasshopper jumps k stones from stone k across a row with destroyed stones. Decide whether it reaches the last stone.	Easy2	SimulationImplementation	No attempts yet	2s	1024 MB	Judgeable
ChessGiven a path of squares a single chess piece visited, list every piece (including white and black pawns) that could have traveled it by its legal moves.	Easy2	ImplementationSimulation	No attempts yet	2s	1024 MB	Judgeable
Sandwich PreparationGiven four axis-aligned rectangles on a grid, find the area of their union so overlapping cells are counted once.	Easy2	ImplementationBrute force	No attempts yet	2s	1024 MB	Judgeable
SequenceGiven a sequence, find the longest subsequence that is not strictly increasing, and print its length and indices, or 0 if none exists.	Easy2	ArrayImplementation	No attempts yet	2s	1024 MB	Judgeable
CurlingFor each end, find the team with the stone closest to the origin and count its stones closer than every opposing stone, then print the totals as a:b.	Easy2	ImplementationMath	No attempts yet	2s	1024 MB	Judgeable
Radio-Controlled Car RaceGiven each car's head start and constant speed, find the earliest time at which two cars are at the same distance from the start.	Easy2	Brute forceMath	No attempts yet	2s	1024 MB	Judgeable
Time StandardsGiven two time standards that set the hours, minutes, and seconds per unit, convert a moment from the first standard to the same moment in the second.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Real NumberGiven a real number x with 0 <= x < 1 and an integer k, round x to k digits after the decimal point, carrying 9s upward as needed.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Beusil's Ttibu-Ttibu Sticker CollectionGiven N uppercase letter stickers, find how many full copies of the word BRONZESILVER can be spelled from them.	Easy2	Hash mapString	No attempts yet	1s	1024 MB	Judgeable
Problems No Larger Than the WeedsCount how many problems have a total character size no greater than the weed size J, where uppercase letters are 4, lowercase letters and digits are 2, and spaces are 1.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
So, how many problems have you solved?Given N, M, and K, find the minimum and maximum problems solved so far when reaching a total of N needs at least M per day for at least K days.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
What Is in the Apple Box? Cash?Given apple and pear juice boxes with their sizes, compute the total mass of the boxes and the market value of the apples inside.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Dynamic ArraySimulate store and delete commands on a dynamic array that doubles when full, then print its final maximum size.	Easy2	ImplementationSimulation+1	No attempts yet	1s	1024 MB	Judgeable