Interview warm-up

Short whiteboard warmups

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Still being built. Things may change

Total results4,880 problems

Minimum Grade
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Character Frequencies
Easy2
Hash map, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Two-Move Knight
Easy2
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Distributing plates
Easy2
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Unreadable Text
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Maximum Climb
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Frog Matching
Easy2
Greedy, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
ZOAC 6
Easy2
String, String matching
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Concert
Easy2
Implementation, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dešifravimas (Decryption)
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Minesweeper
Easy2
Matrix, Implementation+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
We Want You Happy!
Easy2
Simulation, Implementation
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Finding Your Roots
Easy2
Implementation, Linked list
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hurricane Warning
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Lectures
Easy2
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Traffic Light
Easy2
Math, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Making a Rainbow
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Happiness Score
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Find the Zebra!
Easy2
String, Implementation
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Floor Number
Easy2
Implementation, Math
No attempts yet
Time limit
0.2s
Memory limit
1024 MB
Judgeable
Why Hoban-woo Was Late for School 1
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Deciphering WordWhiz
Easy2
Implementation, String
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Democratic Naming
Easy2
Array, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Attendance
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pop-It
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Choosing the Morgorithm President
Easy2
String, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Flight Delays
Easy2
Simulation, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Gahui and Sousenkyo 2
Easy2
Array, Implementation
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Welcome Kit
Easy2
Math, Implementation
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
UOSPC Count
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cheese Comparison
Easy2
Sorting
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Drum
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Knak and the 3D Printer
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
A Choice at the Crossroads
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Dice
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Clever Ines
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Clock
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Triangles
Easy2
Brute force, Geometry
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
I Thought of a Number
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Eurokod
Easy2
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Water Journal
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Counting Consecutive Ascending Subarrays
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ordered Problem Set
Easy2
Implementation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Clock Tower
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
City and Bitcoin
Easy2
Matrix, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Card Game 2
Easy2
Array, Hash map
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Special School Escape
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bingo
Easy2
Array, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Who Won?
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Preliminary Meeting Result Report
Easy2
Implementation, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Team Name Selection 2
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Watermelon Game
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Spreading a Virus in K512
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hyundai Mobis Special Prize 2
Easy2
Brute force, String matching
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Four Vertices of a Cube
Easy2
Implementation, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Snacks within 300 Yen
Easy2
Greedy, Simulation
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
SWAPC
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Snowman
Easy2
Hash map, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cold Shower
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ready for Contest
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bronze Count
Easy2
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rhythm Game
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Magic Compass
Easy2
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
ANA is a palindrome
Easy2
String, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fractions are better when continued
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dishonest Lottery
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
BB84
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Expected Error
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Jumbled Scoreboards
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sauna
Easy2
Array, Implementation
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Obedient Tom
Easy2
Simulation, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hamburger
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bus Assignment
Easy2
Simulation, Array
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Generalized FizzBuzz
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Oooh I See
Easy2
Matrix, Brute force
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Matrix Game
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
RACI Matrix
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Triangle on the Axis
Easy2
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Shooting Practice
Easy2
Simulation, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Drone Control
Easy2
Simulation, Hash map
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bitcoin Halving
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Apartment
Easy2
Simulation, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Jjin Even Number
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Anomaly Mahjong 1
Easy2
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Problem C
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Dorayaki
Easy2
Brute force, Implementation
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Either, but Not Both
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Hezardastan's Annual Report
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Fermat's Fakini
Easy2
Implementation, Hash map
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Glass Reflection
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Alternative Blockchain Algorithms
Easy2
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Game Night
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Sum of a Sequence
Easy3
Math, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Treasure
Easy3
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Divisors
Easy3
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lies
Easy3
Union-find, Graph+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Number Square
Easy3
Brute force, Matrix+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Tournament Meeting Round
Easy3
Simulation, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Friends
Easy3
Graph, Matrix+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
King
Easy3
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Minimum GradeGiven the grades of N-1 courses and a target GPA, find the lowest grade for the last course that makes the truncated semester average exceed the target.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Character FrequenciesCount how many times each non-whitespace character appears in N lines of text and print each character with its count.	Easy2	Hash mapString	No attempts yet	1s	1024 MB	Judgeable
Two-Move KnightGiven a knight's starting square on a chess board, list every square the knight can reach in exactly two moves.	Easy2	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
Distributing platesFind the smallest starting seat from which Juku can hand out plates so that every friend receives a clean plate.	Easy2	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
Unreadable TextGiven N topics and a pattern where '*' marks each unreadable letter, list every topic that matches the pattern in input order.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Maximum ClimbGiven N course heights, find the largest difference between the end and start of a run of consecutive strictly increasing heights.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Frog MatchingGiven Juho at S and N frogs at E_i, find the frog whose jump-then-walk meeting costs the least stamina, and print that cost and its number.	Easy2	GreedyImplementation	No attempts yet	1s	1024 MB	Judgeable
ZOAC 6Count the sentences that contain the substring 01 or OI, since each such sentence gets one Yeongil emoticon.	Easy2	StringString matching	No attempts yet	1s	1024 MB	Judgeable
ConcertGiven seat assignments with one empty seat, count how many listeners must move when listener 1 displaces occupants in a chain until someone reaches the empty seat.	Easy2	ImplementationArray	No attempts yet	1s	1024 MB	Judgeable
Dešifravimas (Decryption)Given a partly encrypted Caesar cipher message and the full encrypted message, find the key from the first differing letter and decrypt the full message.	Easy2	StringSimulation+1	No attempts yet	1s	1024 MB	Judgeable
MinesweeperGiven a solved Minesweeper board, check that every digit equals the number of flagged squares next to it.	Easy2	MatrixImplementation+1	No attempts yet	4s	1024 MB	Judgeable
We Want You Happy!Given arrival, service, and patience times for n customers served in arrival order by one teller, list the customers who are processed without leaving.	Easy2	SimulationImplementation	No attempts yet	5s	1024 MB	Judgeable
Finding Your RootsFor each data set, count how many lions lie on the parent chain from lion L upward, including L, until the chain reaches an unknown parent.	Easy2	ImplementationLinked list	No attempts yet	1s	1024 MB	Judgeable
Hurricane WarningFor each data set, count the people whose consumed media string shares at least one letter with the media string the authorities use for the warning.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
LecturesGiven ten weekly lecture slots, find two that overlap in day and time, or if none do, report the total lecture time.	Easy2	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
Traffic LightGiven drive time M, lap time N, and red interval T, find the laps completed before Mantas first hits a red light, or report that he never stops.	Easy2	MathSimulation	No attempts yet	1s	1024 MB	Judgeable
Making a RainbowGiven a string of letters, decide whether it has enough lowercase, uppercase, or both to spell ROYGBIV, then print yes, YES, YeS, or NO!.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Happiness ScoreGiven one message, count letters that appear in HAPPY and SAD, then print the happiness index as a percentage rounded to two decimals.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Find the Zebra!Count the runs of 1s in each zebra's coat string, then print the maximum run count and how many zebras reach it.	Easy2	StringImplementation	No attempts yet	0.5s	1024 MB	Judgeable
Floor NumberGiven a floor number N and a digit count L, print an L-digit number with no leading zero whose repeated digit-product reduces to N.	Easy2	ImplementationMath	No attempts yet	0.2s	1024 MB	Judgeable
Why Hoban-woo Was Late for School 1Given four stats and a target N, find the fewest +1 blessings needed so the average of the four stats is at least N.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Deciphering WordWhizGiven the secret word and the feedback for each guess, count the dictionary words that would produce that exact feedback against the secret.	Easy2	ImplementationString	No attempts yet	0.5s	1024 MB	Judgeable
Democratic NamingGiven n city names of length m, build the county name by picking, for each position, the letter most cities have there, breaking ties alphabetically.	Easy2	ArrayHash map+1	No attempts yet	1s	1024 MB	Judgeable
AttendanceGiven a log of called names and Present! replies, print the names of students who never answered Present!, in the order they were called.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Pop-ItGiven an h by w grid of 0s and 1s, find the fewest cells to flip so that every cell has the same value.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Choosing the Morgorithm PresidentGiven N distinct uppercase names, print the one that comes first in dictionary order among those with exactly three characters.	Easy2	StringArray	No attempts yet	1s	1024 MB	Judgeable
Flight DelaysGiven scheduled times t_i and a gap k, output each flight's departure: the max of t_i and the previous departure plus k.	Easy2	SimulationArray	No attempts yet	2s	1024 MB	Judgeable
Gahui and Sousenkyo 2Given Gahui's character's vote count and the counts of the other characters, print that character's rank, where more votes means a higher rank.	Easy2	ArrayImplementation	No attempts yet	4s	512 MB	Judgeable
Welcome KitFind the fewest T-shirt bundles of size T that cover each size's requests, and the maximum pen bundles of size P with the leftover single pens.	Easy2	MathImplementation	No attempts yet	0.1s	1024 MB	Judgeable
UOSPC CountRearrange the letters of S to form as many copies of uospc as possible, and print that maximum count.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Cheese ComparisonArrange a set of cheese wheels in order of weight, from smallest to largest, for a market display.	Easy2	Sorting	No attempts yet	3s	1024 MB	Judgeable
DrumGiven hit counts X (left hand) and Y (right hand) per beat, print the order of hits in one beat: 1 for left, 2 for right, 3 for both.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Knak and the 3D PrinterGiven N bar heights of width 1, find the total surface area of the histogram solid, counting the top, bottom, and side faces.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
A Choice at the CrossroadsGiven N miniatures with quality and price, find the two picks under each rule: highest quality (ties by lowest price), and lowest price (ties by highest quality).	Easy2	ArrayImplementation	No attempts yet	1s	512 MB	Judgeable
DiceGiven n dice with f faces and a modifier m, decide whether a reported total S is reachable by checking if S minus m lies between n and n times f.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Clever InesReverse a column-by-column reading of an r x s grid (r at most s, r*s = n, r as large as possible) to recover the original message.	Easy2	ImplementationString+1	No attempts yet	1s	1024 MB	Judgeable
ClockGiven a clock time h and m, find the first moment the hour hand lands on the minute hand's mark, then print that clock time and the elapsed time.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
TrianglesGiven N named points with integer coordinates, list every triple of points that is not collinear, with the names in input order.	Easy2	Brute forceGeometry	No attempts yet	1s	1024 MB	Judgeable
I Thought of a NumberGiven a and b, find the starting number that becomes b after dividing by a, subtracting a, and repeating those two steps once more.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
EurokodGiven the president's ranking and each code's member vote count, print the codes by summed points in descending order, breaking ties by member votes.	Easy2	SortingImplementation	No attempts yet	1s	1024 MB	Judgeable
Water JournalGiven n-1 logged daily water amounts and the true minimum a and maximum b, list every value the missing day could have, or -1 if none fits.	Easy2	ArrayImplementation	No attempts yet	1s	2048 MB	Judgeable
Counting Consecutive Ascending SubarraysGiven a permutation A of length N, count the pairs (i, j) with i at most j where A_i through A_j are strictly increasing.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Ordered Problem SetGiven n distinct difficulties in contest order, list each divisor k greater than 1 of n where every block of n/k consecutive problems is easier than the next block.	Easy2	ImplementationBrute force+1	No attempts yet	1s	2048 MB	Judgeable
Clock TowerGiven the minute M that the altered minute hand points to, find the true minute and print it with one decimal place.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
City and BitcoinDetermines whether a path exists from the top-left to the bottom-right of a grid using only right and down moves through open cells.	Easy2	MatrixDynamic programming	No attempts yet	1s	512 MB	Judgeable
Card Game 2Given N card values, determine whether some integer x exists such that cards with values x, x+3, and x+6 all appear.	Easy2	ArrayHash map	No attempts yet	2s	1024 MB	Judgeable
Special School EscapeGiven N teacher patrol strings over M periods, find the earliest period when no teacher patrols, or report ESCAPE FAILED if none exists.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
BingoGiven bingo boards and a drawn sequence, list the players who have a full row, column, or diagonal marked after m draws, in input order.	Easy2	ArrayHash map+1	No attempts yet	1s	1024 MB	Judgeable
Who Won?Given two sets of 18 problem scores, decide who ranks higher by total, then by the count of 10s, 9s, and so on, or report a tie.	Easy2	ArrayImplementation	No attempts yet	2s	1024 MB	Judgeable
Preliminary Meeting Result ReportCount the teams that solved at least one of three problems, where each solve time is no earlier than the solve time of any lower-numbered problem.	Easy2	ImplementationArray	No attempts yet	1s	1024 MB	Judgeable
Team Name Selection 2Given N candidate team names, print the one that has at most 10 characters, no more uppercase than lowercase letters, and at least one non-digit character.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Watermelon GameGiven N and K cherries, find how many level N watermelons can be made by merging two equal-level fruits into the next level.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Spreading a Virus in K512Process infect and cure queries on N computers, and print how many computers are uninfected for each count query.	Easy2	ArrayImplementation	No attempts yet	2s	512 MB	Judgeable
Hyundai Mobis Special Prize 2Count how many times the word MOBIS can be read in an N by N letter grid, starting from any cell and moving in one of 8 directions.	Easy2	Brute forceString matching	No attempts yet	1s	1024 MB	Judgeable
Four Vertices of a CubeGiven T test cases of four distinct indices of a unit cube's vertices, determine whether each set of four points lies on a single face of the cube.	Easy2	ImplementationBrute force	No attempts yet	1s	1024 MB	Judgeable
Snacks within 300 YenGreedy George walks a shelf of snack prices left to right and buys each snack that keeps his total within 300 yen. The task is to output his total spending for each dataset.	Easy2	GreedySimulation	No attempts yet	8s	1024 MB	Judgeable
SWAPCGiven a string, pair the i-th P with the i-th C in order, swap the two characters in each pair, and print the resulting string.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
SnowmanGiven two rankings of the same players, find the bib numbers that rose the most places, listed in their final rank order.	Easy2	Hash mapImplementation	No attempts yet	1s	1024 MB	Judgeable
Cold ShowerSimulate the shower temperature for n seconds under the given update rule and sum the distances between each temperature and the comfortable temperature k.	Easy2	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Ready for ContestGiven solutions written per problem and language, list the problems that have both a C++ solution and a Java solution, in increasing order.	Easy2	ArrayImplementation	No attempts yet	2s	1024 MB	Judgeable
Bronze CountGiven N participant scores, find the third-highest distinct score and how many participants received that score.	Easy2	SortingImplementation	No attempts yet	1s	1024 MB	Judgeable
Rhythm GameGiven N measures with BPM changes at certain measures, compute the song's total play time in seconds, where each measure has 4 beats.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Magic CompassGiven M compass readings that each give the direction from a cell to a hidden treasure on an N x N grid, find the treasure's cell.	Easy2	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
ANA is a palindromeCount the substrings of S that start and end with A, contain exactly one N, and have no other A.	Easy2	StringBrute force	No attempts yet	1s	1024 MB	Judgeable
Fractions are better when continuedGiven N, print the numerator of p_N, where p_0 = 1 and p_N = 1 / (1 + p_(N-1)), written in lowest terms.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Dishonest LotteryGiven 10n drawings of five distinct numbers from 1 to 50, list every number that appears more than 2n times, or print -1 if none do.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
BB84Given each qubit's basis and value from both sides, build the shared key from positions where the bases match, or print htg! if any matched position disagrees.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Expected ErrorGiven a sudo password of length n, a slip after k correct characters with probability p%, pick the strategy (continue, backspace, or restart) with the lowest expected typing time.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Jumbled ScoreboardsGiven n score pairs in the order the pictures arrived, check whether both teams' scores never decrease from one picture to the next.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
SaunaFind how many temperatures lie in every person's inclusive range and the lowest such temperature, or report bad news if none exist.	Easy2	ArrayImplementation	No attempts yet	1.5s	1024 MB	Judgeable
Obedient TomSimulate placing N colored toys into three capacity-K boxes, trying each toy's preferred box, then the next box in the A-B-C cycle when it is full.	Easy2	SimulationArray	No attempts yet	1s	1024 MB	Judgeable
HamburgerGiven a string S of bread, patty, lettuce, and tomato, check whether it is a valid hamburger: bread at both ends, no equal neighbors, and counts within A, B, C, D.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Bus AssignmentGiven how many people get off and get on at each stop, find the maximum number of passengers on the bus at any one time.	Easy2	SimulationArray	No attempts yet	2s	2048 MB	Judgeable
Generalized FizzBuzzGiven n, a, and b, count how many times Fizz, Buzz, and FizzBuzz are printed in a generalized FizzBuzz run from 1 to n.	Easy2	MathImplementation	No attempts yet	1s	2048 MB	Judgeable
Oooh I SeeGiven a grid of O and 0 characters, find every 0 whose eight neighbors are all O, then print its position, the count, or Oh no!.	Easy2	MatrixBrute force	No attempts yet	1s	2048 MB	Judgeable
Matrix GameFor each column, pick the row that maximizes \|a - b\| there, then sum those maxima over all M columns Chan calls to get the largest possible Diff.	Easy2	ArrayImplementation	No attempts yet	1s	2048 MB	Judgeable
RACI MatrixCheck whether every row of a RACI matrix has exactly one A and at most one R, printing Yes or No.	Easy2	ArrayImplementation	No attempts yet	2s	2048 MB	Judgeable
Triangle on the AxisGiven integer points in the plane, find the largest-area triangle with one side on the Ox axis, or print 0 if no non-degenerate triangle exists.	Easy2	ArrayImplementation	No attempts yet	2s	2048 MB	Judgeable
Shooting PracticeStarting from the cursor at (0, 0), repeatedly shoot the farthest target and sum the squared distances from the cursor to each shot target over M moves.	Easy2	SimulationBrute force	No attempts yet	1s	1024 MB	Judgeable
Drone ControlGiven obstacle cells and a string of U, D, R, L moves, find the drone's final position when it stays put whenever the next cell holds an obstacle.	Easy2	SimulationHash map	No attempts yet	1s	1024 MB	Judgeable
Bitcoin HalvingGiven the initial reward R, the halving interval K, and a block number M, print the mining reward of block M.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
ApartmentRotate a circular stack of 2N hands by each game's count and report the participant at the bottom, keeping the arrangement between games.	Easy2	SimulationArray	No attempts yet	1s	1024 MB	Judgeable
Jjin Even NumberGiven N, count the N-digit Jjin Even Numbers (no leading zero, except 0 itself) modulo 10^9+7 for up to 100,000 queries.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Anomaly Mahjong 1Given a sequence of mahjong tiles, find the position of the first tile whose kind appears a fifth time, or print 0 if no kind reaches five.	Easy2	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Problem CGiven N words, replace each c with k or s by its English pronunciation rule, and replace each ch with c.	Easy2	StringImplementation	No attempts yet	1s	2048 MB	Judgeable
DorayakiGiven tastiness values for N fillings and M skins, sum (a+b) times max(a,b) over every filling and skin pair.	Easy2	Brute forceImplementation	No attempts yet	2s	2048 MB	Judgeable
Either, but Not BothCount the integers from 1 to N that are divisible by exactly one of A and B.	Easy2	MathImplementation	No attempts yet	2s	2048 MB	Judgeable
Hezardastan's Annual ReportGiven the page count of each chapter, find the fewest A4 sheets needed when every chapter starts on an odd page and no sheet mixes two chapters.	Easy2	MathImplementation	No attempts yet	1s	2048 MB	Judgeable
Fermat's FakiniGiven N nicknames split into even and odd gangs, Mirko joins the larger gang and picks the smallest unused natural number with that parity.	Easy2	ImplementationHash map	No attempts yet	1s	2048 MB	Judgeable
Glass ReflectionGiven a reflected string where each run of identical letters is one letter longer than in the original, output the original word.	Easy2	StringImplementation	No attempts yet	1s	2048 MB	Judgeable
Alternative Blockchain AlgorithmsWalk the blocks in order, check each parent id against the previous block id, and print the final balance, NO_MONEY, or INVALID.	Easy2	ImplementationSimulation	No attempts yet	1s	2048 MB	Judgeable
Game NightGiven two equal-length passwords, count the positions where the letters differ, since only those magnets must be fetched from the box.	Easy2	StringImplementation	No attempts yet	2s	2048 MB	Judgeable
Sum of a SequenceGiven N and a minimum length L, find the shortest run of consecutive non-negative integers summing to N, or print -1 if none exists within length 100.	Easy3	MathBrute force+1	No attempts yet	2s	128 MB	Judgeable
TreasureGiven two arrays A and B, rearrange A (B stays fixed) to minimize the sum of elementwise products, using the sorted pairing strategy.	Easy3	GreedySorting+1	No attempts yet	2s	128 MB	Judgeable
DivisorsGiven all proper divisors of an unknown number N, compute N using the fact that the smallest and largest proper divisors multiply to N.	Easy3	MathNumber theory+1	No attempts yet	2s	512 MB	Judgeable
LiesUsing union-find on party attendees, determine which parties can be exaggerated without conflicting with people who must always hear the truth.	Easy3	Union-findGraph+1	No attempts yet	2s	128 MB	Judgeable
Number SquareGiven an N by M grid of digits, find the area of the largest axis-aligned square whose four corner cells share the same digit.	Easy3	Brute forceMatrix+1	No attempts yet	2s	128 MB	Judgeable
Tournament Meeting RoundSimulate a single-elimination tournament where positions are halved each round to find when two specific players first face each other.	Easy3	SimulationMath+1	No attempts yet	1s	512 MB	Judgeable
FriendsGiven an N x N friendship matrix (N ≤ 50), find the maximum count of people reachable within two friendship links from any single person.	Easy3	GraphMatrix+1	No attempts yet	2s	128 MB	Judgeable
KingMove a king on an 8x8 board by given commands; if it lands on the stone, the stone slides one square the same way unless it would leave the board.	Easy3	SimulationImplementation	No attempts yet	2s	128 MB	Judgeable