Problems

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Total results29,474 problems

Star in Parentheses
Easy3
Stack, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Slimming Plan
Easy3
Simulation, Array+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Manhattan
Easy3
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Teenage Mutant
Easy3
Array, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Harshad Numbers
Easy3
Math, Brute force
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Half Seasoned, Half Fried
Easy3
Math, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Snakes and Ladders Game
Easy3
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Strong Password
Easy3
String, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Switches and Lamps
Easy3
Implementation, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
License Plate 1
Easy3
Combinatorics, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
License Plate 2
Easy3
Dynamic programming, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cellphone Text Compression
Easy3
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Flipper
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Shell Game
Easy3
Simulation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sleepy Cow Herding (Bronze)
Easy3
Greedy, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lun
Easy3
Implementation, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Word Clock
Easy3
Implementation, String+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Encoding
Easy3
String, Implementation
No attempts yet
Time limit
8s
Memory limit
1252 MB
Judgeable
3-Minute Graph
Easy3
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sum of Multiples
Easy3
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Total Number of Counts
Easy3
Math, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Constructing a Cyclic Quadrilateral
Easy3
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Phone Number Compatibility
Easy3
Implementation, Simulation+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Passing the Buck
Easy3
Matrix, Implementation+2
No attempts yet
Time limit
0.1s
Memory limit
256 MB
Judgeable
Good Day Bad Day
Easy3
Probability, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Payment Helper for the Moon Rabbit
Easy3
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Fruit Stealing
Easy3
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Integral of a Polynomial
Easy3
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Why Did APC Become a Subtask Contest?
Easy3
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Server Room
Easy3
Sorting, Binary search+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Sam-sam Number
Easy3
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Sam-Sam-Han Number 2
Easy3
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Keyboard Event
Easy3
Sorting, Implementation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
I AM IRONMAN
Easy3
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
League of Legensal (Small)
Easy3
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
I am Groot
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Yumi
Easy3
Brute force, Geometry+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Deeper, The Better
Easy3
Stack, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Only Three!
Easy3
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Worm Reproduction
Easy3
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
What if a car takes the side of its owner, Kim Pyojun?
Easy3
Array, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
What Does Milk Say When It Falls Over?
Easy3
Implementation, Matrix+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
You Have To Solve This One!
Easy3
Sorting, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
N! mod P (2)
Easy3
Implementation, Math
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Typing Practice
Easy3
String, Greedy+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Star Fruit
Easy3
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Claire and Palindrome
Easy3
String, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Floor Plan
Easy3
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hexagonal Rooks
Easy3
Implementation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hamster Ball
Easy3
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Circuit Math
Easy3
Stack, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gerrymandering
Easy3
Implementation, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sticks
Easy3
Array, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Interesting Number
Easy3
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Jazz it Up!
Easy3
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Beer Bill
Easy3
Implementation, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Clock
Easy3
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Lost Lineup
Easy3
Array, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Awkward Party
Easy3
Array, Hash map+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Joint Attack
Easy3
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pongdang Pongdang 2
Easy3
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Pongdang Pongdang 1
Easy3
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Climbing Stairs
Easy3
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Checkerboard
Easy3
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Price Evaluation
Easy3
Implementation, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Mountain Ranges
Easy3
Array, Two pointers+2
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
Expeditious Cubing
Easy3
Math, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
NBA Draft
Easy3
Implementation, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
solved.ac
Easy3
Sorting, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cat Food
Easy3
Implementation, Matrix+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Strange Cipher Code
Easy3
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Summer Hand Fan
Easy3
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Are They All Integers?
Easy3
Brute force, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Issuing Plates
Easy3
String, String matching+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Black and White
Easy3
Array, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Basketball One-on-One
Easy3
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Soft Passwords
Easy3
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Thue-Morse String
Easy3
Bit manipulation, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
ZOAC 2
Easy3
Implementation, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Square Eye Test
Easy3
Implementation, Array+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
A Cipher in Wonderland
Easy3
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Queue 2
Easy3
Queue, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cow Gymnastics
Easy3
Brute force, Array+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Livestock Lineup
Easy3
Brute force, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Boxing Day Football Analysis
Easy3
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Biodiversity
Easy3
Hash map, Implementation+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Icebergs
Easy3
Geometry, Math+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Word Processor
Easy3
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
PRIM
Easy3
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
SECHT
Easy3
String, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
CHROM
Easy3
Array, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
SENTI
Easy3
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
DISPER
Easy3
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sequence and Queries 37
Easy3
Array, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Military Service
Easy3
Math, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Duplicate Files
Easy3
Hash map, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Coffee
Easy3
Hash map, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Inverting bits (Easy)
Easy3
Bit manipulation, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Triangles (Bronze)
Easy3
Brute force, Geometry+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Feedback
Easy3
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Star in ParenthesesGiven balanced parentheses with one star, count the matching pairs that enclose the star's position.	Easy3	StackString+1	No attempts yet	2s	512 MB	Judgeable
Slimming PlanSimulate daily weight changes from the repeating D-day plan and report the day the weight reaches T, or output -1 if it never does.	Easy3	SimulationArray+1	No attempts yet	2s	512 MB	Judgeable
ManhattanGiven the Euclidean distance between two grid-aligned houses, find the maximum Manhattan distance achievable between them.	Easy3	GeometryMath+1	No attempts yet	1s	512 MB	Judgeable
Teenage MutantCompare each of your k trait characters against all n ancestor strings at the same position, count positions where yours differs from every ancestor, and output that count over k.	Easy3	ArrayString+1	No attempts yet	2s	512 MB	Judgeable
Harshad NumbersFind the smallest number at least n that is divisible by its digit sum, for n up to 1,000,000,000.	Easy3	MathBrute force	No attempts yet	2s	512 MB	Judgeable
Half Seasoned, Half FriedGiven prices for seasoned, fried, and half-and-half chicken, find the cheapest way to get at least X seasoned and Y fried pieces.	Easy3	MathGreedy+2	No attempts yet	2s	512 MB	Judgeable
Snakes and Ladders GameOn a 10x10 board with ladders and snakes, find the fewest die rolls to move from square 1 to square 100, where each roll advances 1 to 6.	Easy3	BFSGraph+2	No attempts yet	1s	512 MB	Judgeable
Strong PasswordGiven a string S, find the minimum number of characters to append so it has length at least 6 and contains a digit, a lowercase letter, an uppercase letter, and a special character.	Easy3	StringGreedy+2	No attempts yet	2s	512 MB	Judgeable
Switches and LampsGiven N switches that each light some lamps and together cover every lamp, decide whether leaving out one switch still covers all lamps.	Easy3	ImplementationHash map+2	No attempts yet	2s	512 MB	Judgeable
License Plate 1Given a format string of length at most 4 with c for letter and d for digit, count plates where no two adjacent characters are identical.	Easy3	CombinatoricsMath+2	No attempts yet	1s	512 MB	Judgeable
License Plate 2Count strings matching a pattern of letter and digit slots, where no two adjacent characters are equal, modulo 1,000,000,009.	Easy3	Dynamic programmingMath+2	No attempts yet	1s	512 MB	Judgeable
Cellphone Text CompressionFor each of N strings, output its run-length encoding: each maximal run of identical characters as a count followed by the character.	Easy3	StringImplementation+1	No attempts yet	1s	512 MB	Judgeable
FlipperStart with the grid 1 2 / 3 4 and apply a sequence of horizontal (H) and vertical (V) flips, then print the final grid.	Easy3	SimulationImplementation+1	No attempts yet	1s	512 MB	Judgeable
Shell GameGiven N shell swaps and Elsie's guess after each swap, find the highest number of correct guesses she could make over all possible starting positions of the pebble.	Easy3	SimulationBrute force+2	No attempts yet	2s	512 MB	Judgeable
Sleepy Cow Herding (Bronze)Three cows on a number line move one endpoint at a time; find the minimum and maximum moves to make their three positions consecutive.	Easy3	GreedyMath+2	No attempts yet	2s	512 MB	Judgeable
LunGiven a card number string with one digit replaced by 'x', find the smallest digit for 'x' that makes the number pass the Luhn check.	Easy3	ImplementationMath+2	No attempts yet	1s	512 MB	Judgeable
Word ClockConvert an hour and minute into the words a word clock shows, using past or to and special phrases for 0, 15, 30, and 45 minutes.	Easy3	ImplementationString+2	No attempts yet	0.5s	512 MB	Judgeable
EncodingGiven a Hangul string that was decoded from UTF-8 and re-encoded with another method, print the name of that encoding from five candidates.	Easy3	StringImplementation	No attempts yet	8s	1252 MB	Judgeable
3-Minute GraphSubmit source code to a microwave judge: a program that fails to compile resets the timer with a fresh graph, a compiling one serves it, so the program must compile after roughly three minutes of runtime.	Easy3	ImplementationSimulation	No attempts yet	1s	512 MB	Judgeable
Sum of MultiplesGiven N and a list of divisors K_i, sum every integer from 1 to N that is divisible by at least one K_i, counting each qualifying number once.	Easy3	ImplementationMath+1	No attempts yet	1s	512 MB	Judgeable
Total Number of CountsGiven N bills and bundle size M, repeatedly count items and group them into bundles of M until no bundle can form, then print the total number of counts.	Easy3	MathSimulation+2	No attempts yet	1s	512 MB	Judgeable
Constructing a Cyclic QuadrilateralGiven three decreasing segment lengths where the longest is a diameter of the circumscribed circle, find the fourth side of the cyclic quadrilateral or print -1.	Easy3	GeometryMath+2	No attempts yet	1s	512 MB	Judgeable
Phone Number CompatibilityInterleave two 8-digit phone numbers, repeatedly replace adjacent pairs by the units digit of their sum until two digits remain, and print the score with leading zeros.	Easy3	ImplementationSimulation+1	No attempts yet	2s	256 MB	Judgeable
Passing the BuckGiven two 5x5 matrices A and B, compute each of five people's total workload by a fixed matrix formula and report the least busy person.	Easy3	MatrixImplementation+2	No attempts yet	0.1s	256 MB	Judgeable
Good Day Bad DayGiven a two-state Markov chain's transition probabilities and a starting mood, compute the probability of each mood N days later and print each scaled by 1000.	Easy3	ProbabilityDynamic programming+2	No attempts yet	1s	256 MB	Judgeable
Payment Helper for the Moon RabbitFind the minimum number of 1, 2, 5, and 7 won coins that sum to a given amount N.	Easy3	Dynamic programmingGreedy+1	No attempts yet	1s	256 MB	Judgeable
Fruit StealingCount the ways to distribute M identical stolen fruits among N labeled kinds so each kind receives at least one.	Easy3	CombinatoricsDynamic programming+1	No attempts yet	1s	256 MB	Judgeable
Integral of a PolynomialParse a degree-at-most-1 polynomial string and print its integral, writing x^2 as xx and the constant of integration as W.	Easy3	StringImplementation+2	No attempts yet	1s	256 MB	Judgeable
Why Did APC Become a Subtask Contest?Given N problems each with an easy and hard difficulty and a solve limit K, find the maximum score Hyunjung can earn with skill L. Each problem's easy part is worth 100 and the hard part adds 40, and solving the hard part counts as one problem.	Easy3	GreedySorting+2	No attempts yet	1s	512 MB	Judgeable
Server RoomAir rises one unit per minute from the bottom of an N x N grid of stacked computers; find the earliest minute when at least half of all computers are cooled.	Easy3	SortingBinary search+2	No attempts yet	1s	256 MB	Judgeable
Sam-sam NumberDecide whether N can be written as a sum of distinct powers of 3, using each power at most once.	Easy3	MathImplementation+2	No attempts yet	1s	256 MB	Judgeable
Sam-Sam-Han Number 2Decide whether N can be written as a sum of distinct powers of 3, with at least one term, then print YES or NO.	Easy3	MathNumber theory+2	No attempts yet	1s	256 MB	Judgeable
Keyboard EventGiven key presses with keyboard number, time, and character, print the characters ordered by time, breaking ties by keyboard number.	Easy3	SortingImplementation+1	No attempts yet	1s	256 MB	Judgeable
I AM IRONMANSimulate N games: look up each opponent in a win/loss table, add W or subtract L (floored at 0), and report whether the score ever reaches G.	Easy3	SimulationImplementation+2	No attempts yet	1s	256 MB	Judgeable
League of Legensal (Small)Count sequences of 1-second A casts and M-second B casts that fill exactly N seconds, modulo 1,000,000,007.	Easy3	Dynamic programmingCombinatorics	No attempts yet	1s	256 MB	Judgeable
I am GrootGiven trunk length L and ratio R, branches double each level while length becomes floor(prev*R/100), stopping when a level's length is 5 or less; sum all branch lengths.	Easy3	SimulationImplementation+1	No attempts yet	1s	256 MB	Judgeable
YumiGiven Yumi's position and three fixed people on a plane, find the shortest travel distance for Yumi to visit all three people.	Easy3	Brute forceGeometry+1	No attempts yet	1s	256 MB	Judgeable
The Deeper, The BetterGiven a correct bracket string with digits inside, score each digit by the brackets enclosing it and print the highest score.	Easy3	StackString+1	No attempts yet	1s	256 MB	Judgeable
Only Three!Count how many length-3 windows of a digit string are strictly increasing and are not extended to a run of four or more consecutive digits.	Easy3	StringImplementation+2	No attempts yet	1s	256 MB	Judgeable
Worm ReproductionTrack a worm population over N years where each worm splits yearly and dies after 3 or 4 splits depending on its birth year's parity.	Easy3	SimulationImplementation	No attempts yet	1s	256 MB	Judgeable
What if a car takes the side of its owner, Kim Pyojun?For each window length k from 1 to N, find the starting index of the length-k subarray with the largest standard deviation, breaking ties by the smallest index.	Easy3	ArrayPrefix sum+2	No attempts yet	1s	512 MB	Judgeable
What Does Milk Say When It Falls Over?Given a grid of ASCII art characters, rotate it 90 degrees to the left, mapping each character to its rotated counterpart.	Easy3	ImplementationMatrix+2	No attempts yet	1s	1024 MB	Judgeable
You Have To Solve This One!Sort the array, then answer range-sum queries over the sorted sequence efficiently.	Easy3	SortingPrefix sum+1	No attempts yet	1s	512 MB	Judgeable
N! mod P (2)Given N and a prime P with N < P, compute N! modulo P.	Easy3	ImplementationMath	No attempts yet	3s	1024 MB	Judgeable
Typing PracticeGiven a short sentence, assign each key press (letters plus Shift and space) to the left or right hand under QWERTY rules and balance the counts, letting the left hand press one extra when the difference is one.	Easy3	StringGreedy+1	No attempts yet	1s	256 MB	Judgeable
Star FruitGiven summer length N, growth time T, C plots, and price P, compute the maximum money earnable by planting and replanting each plot as often as possible.	Easy3	GreedyMath+2	No attempts yet	1s	256 MB	Judgeable
Claire and PalindromeFill each '?' in a string with a lowercase letter so the whole string becomes a palindrome, printing any valid result.	Easy3	StringTwo pointers+1	No attempts yet	1s	256 MB	Judgeable
Floor PlanGiven n, find non-negative integers m and k with n = m^2 - k^2, or report that no such pair exists.	Easy3	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
Hexagonal RooksGiven a start and target cell on a side-6 hexagonal board, count the intermediate cells from which a rook reaches the target in exactly two moves.	Easy3	ImplementationBrute force+1	No attempts yet	1s	512 MB	Judgeable
Hamster BallTape can seal a ball only if its tape needed is at most the radius; each ball of radius s costs 2pis, so pick sizes with the cheapest cost per ball.	Easy3	GreedySorting+2	No attempts yet	1s	512 MB	Judgeable
Circuit MathEvaluate a valid postfix boolean circuit over up to 26 variables and print T or F for the given input assignment.	Easy3	StackString+1	No attempts yet	1s	1024 MB	Judgeable
GerrymanderingSum precinct votes into districts, find each district's winner, compute lost and excess wasted votes per party, then output the overall efficiency gap.	Easy3	ImplementationMath+2	No attempts yet	2s	1024 MB	Judgeable
SticksGiven the heights of N sticks in a row, count how many sticks are visible when the row is viewed from the right, where a stick is visible only if it is strictly taller than every stick to its right.	Easy3	ArrayImplementation+2	No attempts yet	1s	512 MB	Judgeable
Interesting NumberCount how many integers from 1 to N are divisible by the sum of their decimal digits.	Easy3	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Jazz it Up!Given a squarefree n between 3 and 100000, find m with 2 <= m < n such that m*n is also squarefree.	Easy3	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
Beer BillParse each bill line as either an item price with optional bars or a bars-only rake line, then print the total (beer at 42) rounded up to a multiple of 10 in the N,- format.	Easy3	ImplementationString+2	No attempts yet	2s	512 MB	Judgeable
ClockGiven a clock time, compute the angles each hand makes with 12 o'clock and report the smallest of the three pairwise angles.	Easy3	MathGeometry+2	No attempts yet	1s	512 MB	Judgeable
Lost LineupGiven each of Jimmy's friends' distance (number of people between them and Jimmy) from the front, reconstruct the original lineup with Jimmy first.	Easy3	ArraySorting+2	No attempts yet	1s	512 MB	Judgeable
Awkward PartyGiven a row of n language labels, find the smallest gap between two positions holding the same label, or n if all labels are distinct.	Easy3	ArrayHash map+1	No attempts yet	1s	512 MB	Judgeable
Joint AttackConvert a continued fraction given as coefficients into a single reduced fraction, with numerator and denominator under 10^18.	Easy3	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Pongdang Pongdang 2Decide whether Hwisu raises an arm on turn T of a circular drinking game where the number of arms per turn cycles up and down between 1 and 2N.	Easy3	MathImplementation+1	No attempts yet	1s	256 MB	Judgeable
Pongdang Pongdang 1Given N players and a turn T, find how many arms must be raised on turn T as the count cycles 1,2,...,2N,2N-1,...,1 repeatedly.	Easy3	MathImplementation+1	No attempts yet	1s	256 MB	Judgeable
Climbing StairsGiven the required walk length n, the desk height r, and the office height k, find the minimum total steps walked in a day while starting and ending on the ground floor.	Easy3	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
CheckerboardGiven row heights and column widths that partition a grid into a v by h block matrix, color each block so side-adjacent blocks differ, starting Black at the top left.	Easy3	ImplementationSimulation+1	No attempts yet	1s	512 MB	Judgeable
Price EvaluationGiven property prices and a list of m property names where some entries are unknown, find the minimum and maximum possible total price.	Easy3	ImplementationGreedy+2	No attempts yet	2s	512 MB	Judgeable
Mountain RangesGiven non-decreasing viewpoint altitudes along a trail, find the length of the longest run where each consecutive altitude increase is at most X, starting anywhere.	Easy3	ArrayTwo pointers+2	No attempts yet	0.1s	512 MB	Judgeable
Expeditious CubingGiven four of Claire's five solve times and a target final score (average of the middle three), find the largest fifth solve time that still meets the target, or report impossible or infinite.	Easy3	MathSorting+2	No attempts yet	2s	512 MB	Judgeable
NBA DraftClassify each player into one of four draft categories by comparing five integer statistics against expected ranges and their midpoints.	Easy3	ImplementationMath+2	No attempts yet	2s	512 MB	Judgeable
solved.acGiven up to 300,000 difficulty votes, output the 30% trimmed mean, rounding the count trimmed at each end and the final average to the nearest integer.	Easy3	SortingMath+1	No attempts yet	1s	1024 MB	Judgeable
Cat FoodGiven a binary picture rotated 90 degrees counterclockwise, check whether it equals the students' picture under the reverse rotation.	Easy3	ImplementationMatrix+2	No attempts yet	1s	1024 MB	Judgeable
Strange Cipher CodeSplit a string into case-insensitive runs of equal letters, map each run to 1 if its length is at least K and 0 otherwise, and drop later runs whose letter already appeared.	Easy3	StringImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Summer Hand FanFor each fan compute the price plus the sum C + 2C + ... + mC for the number of K-hour intervals fully completed during the walk Q, then output the cheapest fan index.	Easy3	MathImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Are They All Integers?Decide whether (A[i]-A[j])/A[k] is an integer for every choice of three distinct indices in a sorted list.	Easy3	Brute forceMath+2	No attempts yet	2s	1024 MB	Judgeable
Issuing PlatesFor each of M plates, decide whether any of N bad words appears as a substring after mapping leetspeak digits to letters.	Easy3	StringString matching+2	No attempts yet	1s	512 MB	Judgeable
Black and WhiteGiven an n by n grid of B and W cells, check that every row and column is balanced and has no three cells of the same color in a row.	Easy3	ArrayImplementation+2	No attempts yet	1s	512 MB	Judgeable
Basketball One-on-OneGiven a string recording who scored and how many points each time, determine which player won the basketball game under the eleven-point and win-by-two rules.	Easy3	ImplementationSimulation+2	No attempts yet	1s	512 MB	Judgeable
Soft PasswordsGiven a stored password S and an entered password P, decide whether P is accepted: equal to S, a digit-prepend/append of S, or the case-reversed form of S.	Easy3	StringImplementation+2	No attempts yet	1s	512 MB	Judgeable
Thue-Morse StringFind the character at position k in the Thue-Morse sequence, where k can be as large as 10^18.	Easy3	Bit manipulationMath+1	No attempts yet	1s	256 MB	Judgeable
ZOAC 2A disk holds the 26 uppercase letters in a circle, and an arrow starts at 'A'. Find the minimum total rotations needed to print a given string in order.	Easy3	ImplementationGreedy+2	No attempts yet	1s	512 MB	Judgeable
Square Eye TestIn a grid containing exactly one colored square border with a one-cell gap at the middle of a side, report which side has the gap.	Easy3	ImplementationArray+2	No attempts yet	1s	512 MB	Judgeable
A Cipher in WonderlandFor the i-th line, read the sentence starting at the first character and print every i-th character in order.	Easy3	StringImplementation	No attempts yet	1s	512 MB	Judgeable
Queue 2Implement a queue supporting push, pop, size, empty, front, and back, and run N commands, printing output for the query commands.	Easy3	QueueImplementation+2	No attempts yet	1s	512 MB	Judgeable
Cow GymnasticsGiven K rankings of N cows, count the pairs where one cow beats the other in every ranking.	Easy3	Brute forceArray+1	No attempts yet	1s	512 MB	Judgeable
Livestock LineupGiven at most 7 'must be milked beside' constraints among 8 cows, output the alphabetically first permutation satisfying all of them.	Easy3	Brute forceBacktracking+2	No attempts yet	1s	512 MB	Judgeable
Boxing Day Football AnalysisGiven the order of N goals scored by two teams, report the final score, the number of tied scores reached during the match, and the longest run of successive goals that flipped a deficit into a lead.	Easy3	SimulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
BiodiversityGiven the species names of N animals, print the species that appears more times than all other species combined, or NONE.	Easy3	Hash mapImplementation+2	No attempts yet	3s	512 MB	Judgeable
IcebergsGiven N simple polygons, compute the total area and print its floor as an integer.	Easy3	GeometryMath+2	No attempts yet	3s	512 MB	Judgeable
Word ProcessorFormat N words into lines of at most K characters using the greedy first-fit rule, then print the result.	Easy3	SimulationImplementation+2	No attempts yet	2s	512 MB	Judgeable
PRIMFor each of T test cases, given an array of n integers, replace every element with the smallest prime that is at least that element, then print the sum.	Easy3	Number theoryMath+2	No attempts yet	2s	512 MB	Judgeable
SECHTDecode a string where each letter was replaced by the uppercase or lowercase form of the character to its left (or lowercase itself if the left is not a letter).	Easy3	StringImplementation	No attempts yet	2s	512 MB	Judgeable
CHROMGiven two parent permutations and two crossover points n and m, build the offspring by keeping parent 1's segment [n, m) in place and filling the rest from parent 2 in order.	Easy3	ArrayImplementation+2	No attempts yet	2s	512 MB	Judgeable
SENTIRead L comments, each ending with a period, and count how many contain a word from a given positive list and how many contain one from a negative list.	Easy3	StringImplementation+1	No attempts yet	2s	512 MB	Judgeable
DISPERFor each professor, treat all student marks as one set, compute the variance of those marks, and report the professor with the highest dispersion to two decimals.	Easy3	MathImplementation+1	No attempts yet	2s	512 MB	Judgeable
Sequence and Queries 37Maintain an array under point updates, and for range queries report how many entries are even or odd.	Easy3	ArrayPrefix sum+2	No attempts yet	1s	512 MB	Judgeable
Military ServiceEach soldier works at most K consecutive months then rests one month; find the largest number of soldiers that can be guaranteed on duty in every month.	Easy3	MathGreedy+1	No attempts yet	2s	512 MB	Judgeable
Duplicate FilesGiven file names and unique IDs, keep the smallest ID for each distinct name and print the surviving IDs in increasing order.	Easy3	Hash mapSorting+1	No attempts yet	2s	512 MB	Judgeable
CoffeeFor each person, add the price of their ordered coffee size to a shared delivery fee of floor(100/P), then snap the total to a multiple of 5 only when it is 1 off.	Easy3	Hash mapImplementation+2	No attempts yet	1s	512 MB	Judgeable
Inverting bits (Easy)Write a program in a tiny 26-register 8-bit assembly language that reads 7 bits and outputs their complements, using the not instruction at most once.	Easy3	Bit manipulationImplementation	No attempts yet	1s	512 MB	Judgeable
Triangles (Bronze)Given up to 100 points, find the largest triangle with one horizontal and one vertical side, and print twice its area.	Easy3	Brute forceGeometry+1	No attempts yet	2s	512 MB	Judgeable
FeedbackBuild a strictly increasing length-N sequence with values at most 1000, second element 2, and last element prime.	Easy3	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable