Interview warm-up

Short whiteboard warmups

Under construction

Still being built. Things may change

Total results4,880 problems

Hedgemony (Small)
Easy2
Simulation, Math
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Quake Live (Small2)
Easy2
Brute force, Combinatorics
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Card Shuffle (Small)
Easy2
Simulation, Array
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Investing at the Market
Easy2
Brute force, Array
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Investing at the Market (Large)
Easy2
Brute force
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Odd Man Out
Easy2
Bit manipulation, Array+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
T9 Spelling (Small)
Easy2
String, Implementation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
XORXORXOR
Easy2
Bit manipulation, Math
No attempts yet
Time limit
0.2s
Memory limit
512 MB
Judgeable
Cameras
Easy2
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Adding god to nicknames
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Manhattan Taxi
Easy2
Implementation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Chop Cup
Easy2
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Divisor Count
Easy2
Number theory, Brute force
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tic Tac Toe
Easy2
Implementation, Matrix+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Palindrome
Easy2
String, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Collatz Sequence
Easy2
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Least Common Multiple
Easy2
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Room Assignment
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jumbled Compass
Easy2
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Stock Investment
Easy2
Array, Greedy
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Graph Maximum Matching
Easy2
Graph, Backtracking+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Data Plan
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Cleaning Stations
Easy2
Implementation, Array+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Walking in time
Easy2
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
The Funniest Digital Laughter
Easy2
String, Two pointers
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Alarm Clock
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Second Cheapest Present
Easy2
Sorting, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Holes
Easy2
String, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Olympic Games
Easy2
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Virus
Easy2
String, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Alpha Puzzle
Easy2
Simulation, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Splitting into Two Teams
Easy2
Brute force, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Luhn Algorithm
Easy2
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Key Maker
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Grades
Easy2
Array, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bridge Honor Points
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
Microwave
Easy2
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Refreshment Area
Easy2
Array, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
One Hundred to Ten
Easy2
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Base 9
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Birthday Graph
Easy2
Array, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Grid Pattern
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Speed Limit
Easy2
Implementation, Math+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Card Game Contest
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Perfect, deficient, or abundant
Easy2
Math, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
2017 Yonsei University Programming Contest
Easy2
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
We Lost Again Today
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
2017 Ajou University Programming Contest (Small)
Easy2
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Empathy
Easy2
Math, String+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Recovering a Damaged ISBN Digit
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
I am happy~
Easy2
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Who Is the Admin?
Easy2
Implementation, Array+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Credit Card Validation
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Paint Estimate
Easy2
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Stacking Cups
Easy2
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pepero Day 2017
Easy2
Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Von Neumann and the Fly
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Coffee Machine
Easy2
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Life Savings
Easy2
Brute force, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Batter Up
Easy2
Implementation, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
No Duplicates
Easy2
String, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Latin Squares
Easy2
Implementation, Array+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Congruent Numbers
Easy2
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Atomic Mass
Easy2
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Analysis of Advanced Analytics
Easy2
Simulation, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Kiwis vs Kangaroos
Easy2
Implementation, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Recently Used Documents
Easy2
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pirates
Easy2
String, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Password check
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Triple Jump
Easy2
Implementation, Array
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hissing Microphone
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sum Squared Digits Function
Easy2
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Santa's Gifts
Easy2
Math, Geometry+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Life Score
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Check the Check
Easy2
Implementation, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Shattered Cake
Easy2
Math, Implementation+2
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Triangles from Five Sticks
Easy2
Brute force, Geometry+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jaccard Similarity Threshold
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pencils
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Array Manipulation at Moloco (Easy)
Easy2
Array, Brute force
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lorem ipsum
Easy2
String, Implementation+1
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
Abbey Courtyard
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sum of Divisors
Easy2
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Is N prime
Easy2
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Rick
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Midterm Exam Grading
Easy2
Implementation, Array+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Teleportation
Easy2
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
PLAYERJINAH’S BOTTLEGROUNDS
Easy2
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Master of the Shell Game
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Overflow and Modulo
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
What Is Your Handle
Easy2
Sorting, String+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
It Worked, So Why Is It Wrong?
Easy2
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Caesar Cipher
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
What Does UCPC Stand For?
Easy2
String, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Suchan Is a Marine Boy!!
Easy2
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Prize Hunter
Easy2
Implementation, Array
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Happiness
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Telemarketer or not?
Easy2
Implementation, Brute force
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Occupy Parking
Easy2
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Are we there yet?
Easy2
Array, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Hedgemony (Small)Simulate a single left-to-right pass that trims each bush to the average of its current neighbors and output the final height of bush N-1.	Easy2	SimulationMath	No attempts yet	5s	512 MB	Judgeable
Quake Live (Small2)Split the given players into two equal teams so the two skill totals differ as little as possible.	Easy2	Brute forceCombinatorics	No attempts yet	5s	512 MB	Judgeable
Card Shuffle (Small)Simulate C segment-to-top cuts on a deck of M ordered cards and report the card at position W.	Easy2	SimulationArray	No attempts yet	5s	512 MB	Judgeable
Investing at the MarketChoose a buy month and a later sell month from 12 prices to maximize whole-unit profit, breaking ties by lower buy price.	Easy2	Brute forceArray	No attempts yet	5s	512 MB	Judgeable
Investing at the Market (Large)Choose one buy month and a later sell month from 12 monthly prices to maximize profit from whole shares bought with fixed money.	Easy2	Brute force	No attempts yet	5s	512 MB	Judgeable
Odd Man OutGiven an odd-length list of invitation codes where every value appears twice except one, find the value that appears once.	Easy2	Bit manipulationArray+1	No attempts yet	5s	512 MB	Judgeable
T9 Spelling (Small)Map each letter of a short message to its keypad digit and repeat count, inserting a space between consecutive letters that share the same key.	Easy2	StringImplementation+2	No attempts yet	5s	512 MB	Judgeable
XORXORXORXOR the value B into A exactly C times and print the result.	Easy2	Bit manipulationMath	No attempts yet	0.2s	512 MB	Judgeable
CamerasRead n eight-character plates and print each one that matches a fixed pattern of digits and a capital letter, in input order.	Easy2	StringImplementation+1	No attempts yet	2s	512 MB	Judgeable
Adding god to nicknamesGiven N nicknames split into syllables by spaces, replace the first syllable with god and print the result.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
Manhattan TaxiGiven your waiting intersection and up to 100 taxi positions on a 100x100 grid, print the coordinates of the taxi with the smallest Manhattan distance.	Easy2	ImplementationBrute force+2	No attempts yet	2s	512 MB	Judgeable
Chop CupTrack which of three cups hides the ball after a sequence of swaps given as letters A, B, and C.	Easy2	SimulationImplementation	No attempts yet	2s	512 MB	Judgeable
Divisor CountFor each of up to 10 values of n below 10000, print n and its divisor count.	Easy2	Number theoryBrute force	No attempts yet	2s	512 MB	Judgeable
Tic Tac ToeRead a 3x3 board of X, O, and dots and print YES if some row, column, or diagonal has three equal non-dot symbols.	Easy2	ImplementationMatrix+1	No attempts yet	2s	512 MB	Judgeable
PalindromeGiven a lowercase word of at most 20 characters, decide whether it reads the same forwards and backwards.	Easy2	StringTwo pointers+1	No attempts yet	2s	512 MB	Judgeable
Collatz SequenceStarting from n, repeatedly apply the Collatz rule (halve evens, 3n+1 for odds) and print every value from n down to 1 on one line.	Easy2	SimulationImplementation+1	No attempts yet	2s	512 MB	Judgeable
Least Common MultipleGiven two integers below 100,000,000, print their least common multiple, which can exceed the 32-bit range.	Easy2	MathNumber theory+1	No attempts yet	2s	512 MB	Judgeable
Room AssignmentCount boys and girls per grade and sum the ceiling of each count divided by the room capacity K.	Easy2	MathImplementation	No attempts yet	2s	512 MB	Judgeable
Jumbled CompassGiven two compass directions from 0 to 359, print the signed rotation with the smallest magnitude that moves the needle from the first direction to the second, breaking ties toward clockwise.	Easy2	MathImplementation+1	No attempts yet	2s	512 MB	Judgeable
Stock InvestmentGiven each day's profit for three stocks, pick at most one stock per day and maximize the total profit.	Easy2	ArrayGreedy	No attempts yet	1s	128 MB	Judgeable
Graph Maximum MatchingGiven a small graph, decide whether some edges can be kept so every vertex has degree exactly 1.	Easy2	GraphBacktracking+1	No attempts yet	2s	512 MB	Judgeable
Data PlanTrack monthly data allowance that rolls over, subtract each month's usage, and report the megabytes available in month N+1.	Easy2	ImplementationMath	No attempts yet	1s	64 MB	Judgeable
Cleaning StationsGiven weights and a feature matrix, print the indices of the rows whose weighted sum is largest, in ascending order, for each of K data sets.	Easy2	ImplementationArray+1	No attempts yet	2s	512 MB	Judgeable
Walking in timeGiven three credit values, decide whether choosing some of them with signs (+ or -) sums to zero using at least one credit.	Easy2	Brute forceMath+1	No attempts yet	1s	512 MB	Judgeable
The Funniest Digital LaughterGiven a string, ignore the consonants and decide whether the remaining vowels read the same forwards and backwards.	Easy2	StringTwo pointers	No attempts yet	1s	512 MB	Judgeable
Alarm ClockFor each case, compute how many minutes pass from the current time until the alarm time, rolling over to the next day when needed.	Easy2	MathImplementation	No attempts yet	2s	512 MB	Judgeable
Second Cheapest PresentGiven a list of distinct prices, print the second cheapest one, formatted with two decimal places.	Easy2	SortingImplementation	No attempts yet	2s	512 MB	Judgeable
HolesCount the holes in each of N lines of uppercase text, where B counts as two, A D O P Q R count as one, and the rest count as zero.	Easy2	StringImplementation+2	No attempts yet	2s	512 MB	Judgeable
Olympic GamesFor each year, decide whether it is a summer Olympic year, and if so whether the games were held, cancelled by a war, or not yet assigned a city.	Easy2	ImplementationMath	No attempts yet	2s	512 MB	Judgeable
VirusGiven a key and one line of ciphertext, undo a Caesar variant whose shift grows by one per letter and resets after 25.	Easy2	StringSimulation+1	No attempts yet	2s	512 MB	Judgeable
Alpha PuzzleAssign numbers 1 to 26 to letters by scanning the grid and numbering each letter at its first appearance.	Easy2	SimulationString+1	No attempts yet	2s	512 MB	Judgeable
Splitting into Two TeamsGiven four sorted skill levels, split them into two pairs of two and print the smallest possible difference between the two pair sums.	Easy2	Brute forceMath+1	No attempts yet	2s	512 MB	Judgeable
Luhn AlgorithmGiven a sixteen-digit card number as a string, check whether it passes the Luhn checksum and print DA or NE.	Easy2	StringImplementation+2	No attempts yet	1s	512 MB	Judgeable
Key MakerFor each test case, count how many trash keys have the same cut count and can be deepened, or already match, the customer key.	Easy2	ArrayImplementation	No attempts yet	2s	512 MB	Judgeable
GradesGiven a list of grades, compare the midpoint of the maximum and minimum against the overall average, and report whether they differ by less than 1.	Easy2	ArrayMath+1	No attempts yet	2s	512 MB	Judgeable
Bridge Honor PointsGiven N strings of 13 card characters, add up honor points (A=4, K=3, Q=2, J=1) across all hands and print the total.	Easy2	ImplementationString+1	No attempts yet	1s	32 MB	Judgeable
MicrowaveGiven a start temperature below target, compute total heating time using per-degree rates for frozen and unfrozen states plus a fixed thawing time.	Easy2	MathImplementation+1	No attempts yet	2s	512 MB	Judgeable
Refreshment AreaCount the number of D-long horizontal or vertical runs of empty cells in an N by M grid.	Easy2	ArrayImplementation+2	No attempts yet	2s	512 MB	Judgeable
One Hundred to TenParse a ratio written as n:m, divide both numbers by their greatest common divisor, and print the reduced ratio in the same format.	Easy2	MathNumber theory+1	No attempts yet	2s	512 MB	Judgeable
Base 9Convert a given decimal integer between 1 and 10000 into its base 9 representation.	Easy2	MathImplementation	No attempts yet	2s	512 MB	Judgeable
Birthday GraphRead dates in dd mm yyyy form and print a star per birthday for each of the twelve months, in a numbered case format.	Easy2	ArrayString+1	No attempts yet	5s	512 MB	Judgeable
Grid PatternFor each case, print a text grid with pipe, minus, and plus lines and asterisk-filled cells of size w by h.	Easy2	ImplementationSimulation+1	No attempts yet	10s	512 MB	Judgeable
Speed LimitFor each log entry, multiply the speed by the time since the previous entry, sum these products, and print the total distance in miles.	Easy2	ImplementationMath+1	No attempts yet	5s	512 MB	Judgeable
Card Game ContestFor each of N games, Meiji has A_i decks, or gets one basic deck if A_i is 0. Count the number of distinct ways to enter, modulo M.	Easy2	MathImplementation+2	No attempts yet	1s	256 MB	Judgeable
Perfect, deficient, or abundantFor each of T numbers below 10000, sum its proper divisors and classify it as Perfect, Deficient, or Abundant.	Easy2	MathBrute force+1	No attempts yet	1s	128 MB	Judgeable
2017 Yonsei University Programming ContestCount triples (A, B, C) with A+B+C = N, all at least 1, C at least B+2, and A even.	Easy2	Brute forceMath+1	No attempts yet	1s	128 MB	Judgeable
We Lost Again TodayGiven the runs each team scored in all nine innings, decide whether the Ullim Geminis ever held a lead during a game they ended up losing.	Easy2	ImplementationSimulation+1	No attempts yet	1s	64 MB	Judgeable
2017 Ajou University Programming Contest (Small)Given up to three contestants' scores, submission counts, and last scoring upload times, output the number of the top-ranked contestant by the tie-break rules.	Easy2	SortingImplementation	No attempts yet	1s	512 MB	Judgeable
EmpathyMultiply two binary numbers up to 30 bits long and print the product in binary without leading zeros.	Easy2	MathString+2	No attempts yet	2s	256 MB	Judgeable
Recovering a Damaged ISBN DigitOne digit of a 13-digit ISBN is replaced by '*', and you print the digit that makes the weighted checksum divisible by 10.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
I am happy~Given the height N, width M, and a seat number K in row-major order, print the row and column of that seat.	Easy2	MathImplementation+2	No attempts yet	2s	256 MB	Judgeable
Who Is the Admin?Given nine clubs with N members each, find the club whose best member solved more problems than the best member of every other club.	Easy2	ImplementationArray+1	No attempts yet	1s	256 MB	Judgeable
Credit Card ValidationFor each 16-digit card number, apply the Luhn checksum (double every second digit from the right, sum digits) and print T if the total is divisible by 10, else F.	Easy2	ImplementationString+1	No attempts yet	1s	128 MB	Judgeable
Paint EstimateFor each floor plan, compute the paintable wall and ceiling area minus window and door areas, multiply by the number of apartments, and round the total up by the coverage of one can.	Easy2	MathImplementation+2	No attempts yet	2s	512 MB	Judgeable
Stacking CupsRead each cup's message, recover its radius from either token order, then print colors from smallest to largest cup.	Easy2	SortingImplementation	No attempts yet	1s	512 MB	Judgeable
Pepero Day 2017Given a time on November 11, 2017, print the Pepero count from the reward rules based on the hour, minute, and second.	Easy2	Implementation	No attempts yet	2s	512 MB	Judgeable
Von Neumann and the FlyGiven train speed S, fly speed T, and initial gap D, compute how far the fly travels before the two trains collide.	Easy2	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Coffee MachineGiven the number of employees on each of three floors, pick the floor for one coffee machine that minimizes total daily stair time.	Easy2	Brute forceMath+1	No attempts yet	1s	1024 MB	Judgeable
Life SavingsCompare the savings from one 20%-style whole-purchase coupon against the best way to spend two one-item coupons on two of three items, then print the winning plan and its savings.	Easy2	Brute forceMath+2	No attempts yet	2s	512 MB	Judgeable
Batter UpRead n at-bat outcomes, sum the bases from official at-bats (0 to 4), divide by how many of them are not walks, and print the result to six decimals.	Easy2	ImplementationMath+2	No attempts yet	2s	512 MB	Judgeable
No DuplicatesRead a line of space-separated uppercase words and print yes if no word repeats, or no if any word appears more than once.	Easy2	StringHash map+1	No attempts yet	2s	512 MB	Judgeable
Latin SquaresRead an n by n grid of base-n digit characters and report whether it is a Latin square, and if so whether it is in reduced form.	Easy2	ImplementationArray+2	No attempts yet	1s	512 MB	Judgeable
Congruent NumbersGiven the two legs of a right triangle as fractions p1/q1 and p2/q2, print 1 if the triangle's area is an integer, otherwise 0.	Easy2	MathNumber theory+1	No attempts yet	2s	512 MB	Judgeable
Atomic MassParse a short chemical formula, look up each element's atomic mass, multiply by any following count, and print the total with two decimals.	Easy2	StringHash map+2	No attempts yet	1s	512 MB	Judgeable
Analysis of Advanced AnalyticsGiven daily page counts and a fixed notebook size, count how many notebooks are needed when each day's notes must fit in one notebook without splitting.	Easy2	SimulationGreedy+1	No attempts yet	1s	512 MB	Judgeable
Kiwis vs KangaroosGiven a phrase, score each side by how often its letters appear in KANGAROO or KIWIBIRD, then report the higher score or a tie.	Easy2	ImplementationString+2	No attempts yet	2s	512 MB	Judgeable
Recently Used DocumentsSimulate a most-recently-used list of capacity k: each opened document moves to the front, new ones are inserted there and the back is dropped when full, then print the final list.	Easy2	SimulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
PiratesGiven a lowercase word, find the letter with the highest frequency and print that letter with its count.	Easy2	StringHash map+1	No attempts yet	2s	512 MB	Judgeable
Password checkFor each of N passwords, report valid if it has a lowercase letter, uppercase letter, digit, symbol, and length at least 12, else invalid.	Easy2	StringImplementation	No attempts yet	2s	512 MB	Judgeable
Triple JumpFind the first step in [30.0, 30.2], then report 30.0 minus the smallest position among steps at least 3 later, or 0 if none exists.	Easy2	ImplementationArray	No attempts yet	2s	512 MB	Judgeable
Hissing MicrophoneGiven a lowercase string, check whether it contains two consecutive s characters and print hiss or no hiss.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
Sum Squared Digits FunctionFor each of P datasets, convert the given integer n to base b, square each digit, and report the total with the dataset number.	Easy2	MathImplementation+1	No attempts yet	2s	512 MB	Judgeable
Santa's GiftsCompute the total straight-line distance from Santa's house through four given points in 3D and check it does not exceed the time limit X.	Easy2	MathGeometry+2	No attempts yet	5s	512 MB	Judgeable
Life ScoreFor each name, sum the letter values (A=1 to Z=26, spaces worth 0) and print the total, or PERFECT LIFE when the total is exactly 100.	Easy2	StringImplementation	No attempts yet	2s	512 MB	Judgeable
Check the CheckRead dish names and price-quantity pairs until the line TOTAL, then print PAY if the waiter's total is at most the sum of price times quantity, else PROTEST.	Easy2	ImplementationString+1	No attempts yet	2s	512 MB	Judgeable
Shattered CakeGiven the cake's width and the dimensions of all shattered rectangular pieces, sum the piece areas and divide by the width to get the length.	Easy2	MathImplementation+2	No attempts yet	10s	512 MB	Judgeable
Triangles from Five SticksGiven five distinct stick lengths, count how many 3-stick subsets can form a triangle with positive area.	Easy2	Brute forceGeometry+1	No attempts yet	2s	512 MB	Judgeable
Jaccard Similarity ThresholdGiven two small sets of digits, decide whether their Jaccard similarity is greater than 0.5.	Easy2	ImplementationMath	No attempts yet	1s	512 MB	Judgeable
PencilsChoose either set X or set Y, buy any number of copies of that one set, and pay the least to reach at least N pencils.	Easy2	MathImplementation	No attempts yet	2s	512 MB	Judgeable
Array Manipulation at Moloco (Easy)For each element, count how many earlier elements in the array are smaller, and print those counts one per line.	Easy2	ArrayBrute force	No attempts yet	2s	512 MB	Judgeable
Lorem ipsumSplit a fixed Latin placeholder paragraph into words and print the words at indices L through R separated by spaces.	Easy2	StringImplementation+1	No attempts yet	0.1s	512 MB	Judgeable
Abbey CourtyardGiven the area of a square courtyard, compute the perimeter as 4 times the square root of the area, rounded to six decimal places.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
Sum of DivisorsGiven a natural number n up to 10000, print the sum of all its positive divisors, with 1 and n included.	Easy2	MathBrute force	No attempts yet	1s	256 MB	Judgeable
Is N primeGiven an integer N, decide whether N is prime and print Yes or No. The trailing line of N integers is unused.	Easy2	MathNumber theory+1	No attempts yet	1s	256 MB	Judgeable
RickRead one line and print NO if it exactly matches one of six given phrases, otherwise print YES.	Easy2	StringImplementation	No attempts yet	1s	256 MB	Judgeable
Midterm Exam GradingGiven point values for N problems and each examinee's O/X results, find the highest scorer, breaking ties by the smallest exam number.	Easy2	ImplementationArray+1	No attempts yet	1s	512 MB	Judgeable
TeleportationGiven start a, end b, and a bidirectional teleporter linking x and y, find the minimum tractor distance to move from a to b, with the option to skip the teleporter.	Easy2	MathImplementation+2	No attempts yet	2s	512 MB	Judgeable
PLAYERJINAH’S BOTTLEGROUNDSGiven the coordinates of three distinct points, decide whether they lie on a single straight line.	Easy2	GeometryMath+1	No attempts yet	1s	512 MB	Judgeable
Master of the Shell GameGiven a string, perform T swaps of characters at the given 0-indexed positions in order and print the final string.	Easy2	StringSimulation+1	No attempts yet	1s	128 MB	Judgeable
Overflow and ModuloMultiply N integers and print the product modulo M, reducing after each multiplication to avoid overflow.	Easy2	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
What Is Your HandleSort N distinct handles by ASCII dictionary order and print the I-th one.	Easy2	SortingString+1	No attempts yet	1s	512 MB	Judgeable
It Worked, So Why Is It Wrong?Compare the expected answer with Manyoung's output for each sample and system test case, then print Accepted, Wrong Answer, or Why Wrong!!! according to which group fails.	Easy2	ImplementationSimulation+2	No attempts yet	1s	512 MB	Judgeable
Caesar CipherShift every letter of a string by k positions in the alphabet, wrapping around, and leave spaces, periods, and commas unchanged.	Easy2	StringImplementation+1	No attempts yet	1s	64 MB	Judgeable
What Does UCPC Stand For?Given one string, decide whether deleting some characters can leave exactly the subsequence UCPC, case sensitive.	Easy2	StringGreedy+1	No attempts yet	1s	512 MB	Judgeable
Suchan Is a Marine Boy!!Given N practice records, compute the ratio of their arithmetic mean to the expected value of a value drawn uniformly from them, or print divide by zero.	Easy2	MathImplementation+2	No attempts yet	2s	512 MB	Judgeable
Prize HunterGiven two ranks a and b from two contests, print the total prize money using each contest's published prize table.	Easy2	ImplementationArray	No attempts yet	1s	512 MB	Judgeable
HappinessRead N scores and print the difference between the maximum and minimum score.	Easy2	ArrayImplementation	No attempts yet	2s	512 MB	Judgeable
Telemarketer or not?Given four digits, print "ignore" if the first and last are 8 or 9 and the middle two are equal, otherwise print "answer".	Easy2	ImplementationBrute force	No attempts yet	2s	512 MB	Judgeable
Occupy ParkingCount how many of the N parking spaces show 'C' in both the yesterday string and the today string.	Easy2	StringImplementation+1	No attempts yet	2s	512 MB	Judgeable
Are we there yet?Given four distances between consecutive cities on a line, print the full 5x5 table of distances between every pair of cities.	Easy2	ArrayPrefix sum+2	No attempts yet	2s	512 MB	Judgeable