Interview warm-up

Short whiteboard warmups

Under construction

Still being built. Things may change

Total results4,880 problems

Choosing a Team Name
Easy2
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
TV Size
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Group Word Checker
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Year Progress Bar
Easy2
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Actual Disk Space
Easy2
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Yujin Number
Easy2
String, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Reversed Addition
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Pet
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Most Frequent Letters
Easy2
Hash map, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Earrings
Easy2
Hash map, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Floor Decoration
Easy2
Matrix, Implementation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Song Scores
Easy2
Prefix sum, Binary search+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
24-Hour Mission
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Sort Digits Descending
Easy2
Sorting, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Organizing Books
Easy2
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Time Machine
Easy2
Combinatorics, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Internet Cafe Seat Requests
Easy2
Simulation, Array+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Room Number
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Adjusted Average
Easy2
Array, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Ball
Easy2
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Sequence Transformation
Easy2
Array, Simulation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Manhattan Distance on a Four-Row Number Board
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Find Places to Lie Down
Easy2
Matrix, Simulation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Trophy Display
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Chicken Coupons
Easy2
Math, Simulation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Growth Points
Easy2
Simulation, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Next Term in a Sequence
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Fraction Sum
Easy2
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Concatenating Numbers 1
Easy2
Math, Implementation
No attempts yet
Time limit
0.15s
Memory limit
128 MB
Judgeable
Packing Books into Boxes
Easy2
Greedy, Array+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Numbers With Equal Remainder and Quotient
Easy2
Math
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Octopus Numbers
Easy2
String, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Good License Plates
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fourth Point
Easy2
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Making Anagrams
Easy2
Hash map, String
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Year 2007
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Least Common Multiple
Easy2
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Counting Pentagon Points
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Perfect Squares
Easy2
Math, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Counting Primes
Easy2
Math, Brute force
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Plugs
Easy2
Math, Greedy+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Self-Replicating Number
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Day of the Year
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Number Game
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Prime Word
Easy2
String, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Dobby's Case-Insensitive Word Test
Easy2
String, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Restoring Numbers
Easy2
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Sum of Consecutive Integers
Easy2
Math, Implementation
No attempts yet
Time limit
0.25s
Memory limit
128 MB
Judgeable
Weather Intern's Temperature Sum
Easy2
Sliding window, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Right-Aligned Stars
Easy2
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Star Printing - 6
Easy2
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Star Printing - 8
Easy2
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Intelligent Train
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Intelligent Train 2
Easy2
Simulation, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dice Game
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Three Dice
Easy2
Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Longest Digit Run
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Find the K-th Divisor
Easy2
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Score Calculation
Easy2
Array, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Card Game
Easy2
Simulation, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
AI Oven Clock
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Candy Teacher Go Changyoung
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Maximum Value
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Digit Counts in a Product
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Average and Mode
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Virus
Easy2
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Greatest Common Divisor and Least Common Multiple
Easy2
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Coin Game
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Third Largest Number
Easy2
Sorting, Array
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
Cryptoquote
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
U.S. Unit Conversion
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Laundry Owner Donghyuk
Easy2
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Binary Addition
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Matrix Multiplication
Easy2
Matrix, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Base Conversion
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fibonacci Number 2
Easy2
Dynamic programming, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
What Is This Semester's GPA?
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Triangular Gimbap Price Comparison
Easy2
Math, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Score Calculation
Easy2
Sorting, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sugar Delivery
Easy2
Greedy, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Uphill Road
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Super Mario
Easy2
Array, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Maximum Value of a Fraction Table
Easy2
Brute force, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Difference Between 5 and 6
Easy2
String, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Climbing Snail
Easy2
Math, Simulation
No attempts yet
Time limit
0.25s
Memory limit
128 MB
Judgeable
Monster Truck
Easy2
Matrix, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Why Is KMP Called KMP?
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Copyright
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dominoes
Easy2
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Year 2009
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
I Am a Chef
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Changyeong's Diary
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Answer Pattern Guessing
Easy2
Simulation, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
ATM Transactions
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Octal
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fourth Point
Easy2
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Equal-Size Interval Clustering
Easy2
Sorting, Array+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Changyeong Village Cup Shuffle
Easy2
Simulation, String
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Time Until the Warning
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Angry Changyoung
Easy2
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Choosing a Team NameCount letters L,O,V,E across a fixed name plus each candidate string, compute a formula mod 100, and print the candidate with the highest value, breaking ties by lexicographic order.	Easy2	StringImplementation+1	No attempts yet	2s	128 MB	Judgeable
TV SizeGiven a TV's diagonal length and height-to-width ratio, compute the actual height and width, flooring non-integer results.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
Group Word CheckerCount how many of up to 100 lowercase words have every repeated character forming a single contiguous block.	Easy2	StringImplementation	No attempts yet	2s	128 MB	Judgeable
Year Progress BarGiven a date and time string, compute what percentage of the current year (accounting for leap years) has elapsed.	Easy2	ImplementationMath	No attempts yet	2s	128 MB	Judgeable
Actual Disk SpaceGiven N file sizes and a cluster size, compute total disk space used by rounding each file up to the nearest cluster multiple and summing.	Easy2	MathImplementation+1	No attempts yet	2s	128 MB	Judgeable
Yujin NumberGiven an integer up to about 2.1 billion, determine whether some split of its digits into a left and right part yields equal digit products.	Easy2	StringBrute force+1	No attempts yet	2s	128 MB	Judgeable
Reversed AdditionReverse the digits of two numbers up to 1000, add the reversed values, then reverse the sum and print the result.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
PetSimulate feeding and exercising a pet's weight across scenarios and report whether it ends happy, sad, or dead based on simple weight thresholds.	Easy2	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
Most Frequent LettersCount lowercase letter frequencies across up to 50 lines of text and print all letters tied for the highest frequency in alphabetical order.	Easy2	Hash mapString+1	No attempts yet	2s	128 MB	Judgeable
EarringsGiven girl names and 2n-1 confiscation/return records tagged with a number and a letter, find the girl whose number appears only once and thus never got her earring back.	Easy2	Hash mapArray+1	No attempts yet	1s	128 MB	Judgeable
Floor DecorationCount the number of wooden planks by counting maximal runs of consecutive '-' in each row and '\|' in each column of a grid.	Easy2	MatrixImplementation+1	No attempts yet	2s	128 MB	Judgeable
Song ScoresGiven cumulative durations of N song scores, answer Q queries asking which score is being sung at a given time using prefix sums and search.	Easy2	Prefix sumBinary search+1	No attempts yet	2s	128 MB	Judgeable
24-Hour MissionGiven the current time and a start time in HH:MM:SS, compute the time remaining until the start time next occurs within a 24-hour cycle.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
Sort Digits DescendingRearrange the digits of a given natural number so they appear in descending order and print the result.	Easy2	SortingString+1	No attempts yet	2s	128 MB	Judgeable
Organizing BooksSimulate packing books into boxes in order, sealing a box once the next book no longer fits, and sum the leftover capacity of every box.	Easy2	SimulationImplementation+1	No attempts yet	2s	128 MB	Judgeable
Time MachineGiven three two-digit numbers from a digital clock, count how many of the 6 permutations form a valid HH:MM:SS time.	Easy2	CombinatoricsBrute force+1	No attempts yet	2s	128 MB	Judgeable
Internet Cafe Seat RequestsGiven a sequence of seat requests for 100 computers, count how many requests are rejected because the requested seat is already taken.	Easy2	SimulationArray+1	No attempts yet	2s	128 MB	Judgeable
Room NumberGiven a room number, count how many plastic digit sets (0-9 each) are needed, treating 6 and 9 as interchangeable when flipped.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
Adjusted AverageGiven N exam scores, rescale each by dividing by the maximum score and multiplying by 100, then output the average of the rescaled scores.	Easy2	ArrayMath+1	No attempts yet	2s	128 MB	Judgeable
BallTrack which of three cups covers a ball as cups swap positions M times, then output the cup number holding it.	Easy2	SimulationImplementation	No attempts yet	2s	128 MB	Judgeable
Sequence TransformationRepeatedly replace a sequence with its adjacent differences K times and print the resulting shorter sequence.	Easy2	ArraySimulation+1	No attempts yet	2s	128 MB	Judgeable
Manhattan Distance on a Four-Row Number BoardGiven two numbers placed column by column in a 4-row grid, compute the Manhattan distance between their cell positions.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
Find Places to Lie DownCount maximal horizontal and vertical runs of at least two consecutive empty cells in an N x N grid.	Easy2	MatrixSimulation	No attempts yet	2s	128 MB	Judgeable
Trophy DisplayCount how many trophies form a visible prefix-maximum sequence when scanning the row from the left and separately from the right.	Easy2	ArrayImplementation	No attempts yet	2s	128 MB	Judgeable
Chicken CouponsGiven n chicken coupons and a stamp-to-coupon exchange rate k, compute the maximum chickens obtainable by repeatedly redeeming stamps for new coupons.	Easy2	MathSimulation+1	No attempts yet	2s	128 MB	Judgeable
Growth PointsSimulate a tree that multiplies its leaves by a yearly factor then subtracts pruned branches, and report the final leaf count.	Easy2	SimulationMath	No attempts yet	1s	128 MB	Judgeable
Next Term in a SequenceGiven a sequence that is either arithmetic or geometric, determine which type it is and output its next term.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
Fraction SumAdd two given fractions and output the sum reduced to lowest terms using GCD.	Easy2	MathNumber theory+1	No attempts yet	2s	128 MB	Judgeable
Concatenating Numbers 1Compute the total digit count when integers from 1 to N are written consecutively without spaces.	Easy2	MathImplementation	No attempts yet	0.15s	128 MB	Judgeable
Packing Books into BoxesGiven book weights in order and a per-box weight limit, compute the minimum number of boxes needed by greedily filling each box in sequence.	Easy2	GreedyArray+1	No attempts yet	2s	128 MB	Judgeable
Numbers With Equal Remainder and QuotientGiven N, find the sum of all positive integers x whose quotient and remainder are equal when divided by N.	Easy2	Math	No attempts yet	2s	256 MB	Judgeable
Octopus NumbersConvert base-8 strings using nine special symbols (including one for digit -1) into their decimal integer values until a terminator line appears.	Easy2	StringMath+1	No attempts yet	1s	128 MB	Judgeable
Good License PlatesFor each license plate, compute a base-26 value from the three letters and compare it to the four-digit number, printing whether their difference is within 100.	Easy2	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
Fourth PointGiven two adjacent sides of a parallelogram as endpoint coordinates, compute and print the fourth vertex for each line of input.	Easy2	GeometryMath+1	No attempts yet	2s	128 MB	Judgeable
Making AnagramsGiven two lowercase words, compute how many letters must be deleted in total so their remaining letters match as multisets (anagrams).	Easy2	Hash mapString	No attempts yet	2s	128 MB	Judgeable
Year 2007Given a month and day in 2007, compute and print the corresponding day of the week starting from Monday, Jan 1.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
Least Common MultipleFor each of up to 1000 pairs of numbers, compute and print the least common multiple.	Easy2	MathNumber theory	No attempts yet	1s	128 MB	Judgeable
Counting Pentagon PointsCompute the total pentagonal points after N steps using a simple arithmetic formula, modulo 45678.	Easy2	MathImplementation	No attempts yet	2s	256 MB	Judgeable
Perfect SquaresGiven two numbers M and N up to 10000, sum all perfect squares in that inclusive range and print the smallest one, or -1 if none exist.	Easy2	MathBrute force+1	No attempts yet	2s	128 MB	Judgeable
Counting PrimesCount how many of up to 100 given numbers (each at most 1000) are prime.	Easy2	MathBrute force	No attempts yet	2s	128 MB	Judgeable
PlugsGiven N power strips each with a plug capacity, compute the max number of computers powered when strips are chained from one wall outlet.	Easy2	MathGreedy+1	No attempts yet	2s	256 MB	Judgeable
Self-Replicating NumberCheck whether squaring an integer N reproduces N as the trailing digits of N squared.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
Day of the YearGiven day, month, year, compute the day's ordinal number within that year accounting for leap years, until a 0 0 0 terminator.	Easy2	ImplementationMath	No attempts yet	1s	128 MB	Judgeable
Number GameRepeatedly sum decimal digits of each number until one digit remains, processing lines until a terminating zero.	Easy2	MathImplementation	No attempts yet	2s	128 MB	Judgeable
Prime WordSum letter values (a-z=1-26, A-Z=27-52) for a word and print whether the sum is prime (with 1 counted as prime).	Easy2	StringMath+1	No attempts yet	2s	128 MB	Judgeable
Dobby's Case-Insensitive Word TestFor each test case, output the original-cased word that is smallest in dictionary order when comparisons ignore letter case.	Easy2	StringSorting+1	No attempts yet	1s	128 MB	Judgeable
Restoring NumbersFor each given integer up to 100,000, output its prime factorization as prime-exponent pairs in increasing order.	Easy2	MathNumber theory+1	No attempts yet	2s	128 MB	Judgeable
Sum of Consecutive IntegersGiven two integers, print the sum of all integers in the closed range between them, handling either order.	Easy2	MathImplementation	No attempts yet	0.25s	128 MB	Judgeable
Weather Intern's Temperature SumGiven N daily temperatures, find the maximum sum over any contiguous window of exactly K days.	Easy2	Sliding windowArray	No attempts yet	1s	128 MB	Judgeable
Right-Aligned StarsPrint N lines of right-aligned stars, where line i has i stars padded with leading spaces to align the right edge.	Easy2	ImplementationSimulation	No attempts yet	1s	128 MB	Judgeable
Star Printing - 6Print a centered triangle of stars whose width decreases by 2 each line from 2N-1 down to 1.	Easy2	ImplementationSimulation	No attempts yet	1s	128 MB	Judgeable
Star Printing - 8Print a diamond-like star pattern of width 2N where side star counts rise from 1 to N then fall back to 1, with spaces filling the middle.	Easy2	ImplementationSimulation	No attempts yet	1s	128 MB	Judgeable
Intelligent TrainSimulate passengers getting off and on at four stations and output the maximum train occupancy at any point.	Easy2	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
Intelligent Train 2Given boarding and alighting counts at 10 stations, simulate the running passenger total and print its maximum value.	Easy2	SimulationArray	No attempts yet	1s	128 MB	Judgeable
Dice GameFor each player's three dice rolls, compute a prize using given rules and print the maximum prize among all players.	Easy2	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
Three DiceGiven three dice values from 1 to 6, compute a prize following fixed rules for triples, pairs, or all different values.	Easy2	Implementation	No attempts yet	1s	128 MB	Judgeable
Longest Digit RunFor three given eight-digit numbers, print the length of the longest run of identical consecutive digits in each.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
Find the K-th DivisorGiven N and K, find and print the K-th smallest divisor of N, or 0 if it doesn't exist.	Easy2	MathBrute force	No attempts yet	1s	128 MB	Judgeable
Score CalculationCompute a total score from a 0/1 sequence where consecutive correct answers score an increasing running count.	Easy2	ArraySimulation+1	No attempts yet	1s	128 MB	Judgeable
Card GameSimulate 10 rounds of card comparisons between two players, scoring points, and determine the overall winner using the most recent non-tied round as a tiebreaker.	Easy2	SimulationArray	No attempts yet	1s	128 MB	Judgeable
AI Oven ClockGiven a start time in hours, minutes, seconds and a duration in seconds, compute the finishing time on a 24-hour clock that wraps around.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Candy Teacher Go ChangyoungCheck whether the total number of candies among N students can be evenly divided among them (sum divisible by N).	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Maximum ValueGiven a 9x9 grid of numbers, find the maximum value and print its row and column position.	Easy2	ArrayImplementation	No attempts yet	1s	128 MB	Judgeable
Digit Counts in a ProductGiven three 3-digit natural numbers, compute their product and count how many times each digit 0 to 9 appears in it.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Average and ModeGiven ten natural numbers, compute and print their average and the most frequently occurring value.	Easy2	ArrayImplementation	No attempts yet	1s	128 MB	Judgeable
VirusCount how many computers other than computer 1 lie in computer 1's connected component of a small undirected graph.	Easy2	GraphBFS+1	No attempts yet	1s	128 MB	Judgeable
Greatest Common Divisor and Least Common MultipleGiven two natural numbers up to 10000, output their greatest common divisor and least common multiple.	Easy2	MathNumber theory	No attempts yet	1s	128 MB	Judgeable
Coin GameCount occurrences of each of 8 possible length-3 head/tail patterns among all consecutive triples in a 40-character coin toss string, for multiple test cases.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
Third Largest NumberFor each test case of 10 positive integers, output the third largest distinct-position value in the array.	Easy2	SortingArray	No attempts yet	1s	32 MB	Judgeable
CryptoquoteDecode each ciphertext message by substituting letters using a given 26-letter mapping while preserving spaces.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
U.S. Unit ConversionConvert given values between kilograms/pounds and liters/gallons using fixed conversion factors, rounding to four decimal places.	Easy2	ImplementationMath	No attempts yet	1s	128 MB	Judgeable
Laundry Owner DonghyukGiven a number of cents, output the minimum count of quarters, dimes, nickels, and pennies using a greedy coin breakdown.	Easy2	GreedyMath+1	No attempts yet	1s	128 MB	Judgeable
Binary AdditionAdd two binary strings up to length 80 for multiple test cases and print the sum without leading zeros.	Easy2	StringSimulation+1	No attempts yet	1s	128 MB	Judgeable
Matrix MultiplicationRead two matrices of bounded size and print their standard matrix product.	Easy2	MatrixImplementation	No attempts yet	1s	128 MB	Judgeable
Base ConversionConvert a number given in an arbitrary base (2 to 36, using letters for digits above 9) into its decimal value.	Easy2	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
Fibonacci Number 2Compute the nth Fibonacci number for n up to 90.	Easy2	Dynamic programmingMath	No attempts yet	1s	128 MB	Judgeable
What Is This Semester's GPA?Compute a weighted GPA from a list of courses, credits, and letter grades, rounded to two decimal places.	Easy2	ImplementationMath	No attempts yet	1s	128 MB	Judgeable
Triangular Gimbap Price ComparisonGiven several price rates for gimbap, compute the cheapest cost to buy exactly 1000 grams using the best per-gram rate among all stores.	Easy2	MathGreedy+1	No attempts yet	1s	128 MB	Judgeable
Score CalculationGiven 8 distinct problem scores, output the sum of the top 5 and their original indices in increasing order.	Easy2	SortingArray+1	No attempts yet	1s	128 MB	Judgeable
Sugar DeliveryFind the minimum number of 3kg and 5kg bags that sum to exactly N kilograms, or -1 if impossible.	Easy2	GreedyMath	No attempts yet	1s	128 MB	Judgeable
Uphill RoadGiven a sequence of heights, find the maximum height difference over the longest strictly increasing consecutive run.	Easy2	ArrayImplementation	No attempts yet	1s	128 MB	Judgeable
Super MarioGiven 10 mushroom scores, pick a prefix sum closest to 100 (preferring the larger one on ties) as Mario's final score.	Easy2	ArrayBrute force+1	No attempts yet	1s	128 MB	Judgeable
Maximum Value of a Fraction TableGiven a 2x2 grid of positive integers, find how many 90-degree clockwise rotations (0-3) maximize A/C+B/D, choosing the smallest such count on ties.	Easy2	Brute forceImplementation+1	No attempts yet	1s	128 MB	Judgeable
Difference Between 5 and 6Given two integers, compute the minimum and maximum possible sums after freely swapping digits 5 and 6 in each number.	Easy2	StringGreedy+1	No attempts yet	1s	128 MB	Judgeable
Climbing SnailCompute the number of days for a snail climbing A meters by day and sliding B meters by night to reach a pole of height V.	Easy2	MathSimulation	No attempts yet	0.25s	128 MB	Judgeable
Monster TruckCount 2x2 blocks in a grid without any building, grouped by how many parked cars they contain (0 to 4).	Easy2	MatrixImplementation	No attempts yet	1s	128 MB	Judgeable
Why Is KMP Called KMP?Convert a hyphen-joined full name like Knuth-Morris-Pratt into its initials such as KMP.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
CopyrightGiven A songs and a rounded-up average I, find the smallest total copyrighted melodies consistent with ceil(total/A) = I.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
DominoesGiven N, compute the total dot count across all unique dominoes with halves ranging from 0 to N.	Easy2	MathCombinatorics	No attempts yet	1s	128 MB	Judgeable
Year 2009Given a day and month in the year 2009, output the English name of the weekday for that date.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
I Am a ChefGiven four scores each for five contestants, output the number and total score of the contestant with the highest sum.	Easy2	ArrayImplementation	No attempts yet	1s	128 MB	Judgeable
Changyeong's DiaryDecode a string by replacing every vowel-p-vowel triple with the single vowel, restoring the original sentence.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
Answer Pattern GuessingGiven an answer string, count matches against three fixed repeating guess patterns and report the highest score and who achieved it.	Easy2	SimulationString+1	No attempts yet	1s	128 MB	Judgeable
ATM TransactionsProcess ATM withdrawal or deposit lines, updating balance but rejecting withdrawals that push it below -200, until a sentinel line ends input.	Easy2	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
OctalConvert a binary string (up to 100 digits) to octal by padding and grouping bits in threes using the given table.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
Fourth PointGiven three corners of an axis-aligned rectangle, compute the coordinates of the missing fourth corner.	Easy2	GeometryMath+1	No attempts yet	1s	128 MB	Judgeable
Equal-Size Interval ClusteringSort points lexicographically, split them into K consecutive groups of nearly equal size, and print each group's coordinate average.	Easy2	SortingArray+1	No attempts yet	5s	128 MB	Judgeable
Changyeong Village Cup ShuffleTrack the position of a ball among three cups after a sequence of swap operations described by characters A, B, C.	Easy2	SimulationString	No attempts yet	1s	128 MB	Judgeable
Time Until the WarningGiven current time and a future warning time in a day, compute the wait time as a difference modulo 24 hours, printing 24:00:00 if they match.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Angry ChangyoungFor each match length, decide if it fits diagonally inside a W by H rectangle and print DA or NE accordingly.	Easy2	GeometryMath+1	No attempts yet	1s	128 MB	Judgeable