Problems

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Total results29,478 problems

S-Trees
Easy3
Tree, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Four Quarters
Easy3
Probability, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Drunken Jailer
Easy3
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bode Plot
Easy3
Math, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Set Me
Easy3
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Digital Root
Easy3
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Clock Patience
Easy3
Simulation, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Floppies
Easy3
Math, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Transaction Processing
Easy3
Implementation, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Circle Through Three Points
Easy3
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Adam's Genes
Easy3
Hash map, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Prime Cuts
Easy3
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Uniform Generator
Easy3
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Unix ls Column Formatting
Easy3
Sorting, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Palindromes
Easy3
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Factorial Frequencies
Easy3
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Evaluating Simple C Expressions
Easy3
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shipping Routes
Easy3
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Donghyeok Pizza
Easy3
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Kilometers to Miles
Easy3
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Black and White Painting
Easy3
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ambiguous Permutations
Easy3
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Help the problem setter
Easy3
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Edge
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Genetic Code
Easy3
String, Recursion
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Subsequence
Easy3
Two pointers, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Polygon Programming with Ease
Easy3
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Paths on a Grid
Easy3
Combinatorics, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Average is not Fast Enough!
Easy3
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
HTML
Easy3
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Artificial Intelligence?
Easy3
String, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Balancing Bank Accounts
Easy3
Prefix sum, Hash map+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Error Correction
Easy3
Implementation, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Globetrotter
Easy3
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Circumference of a Circle
Easy3
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mosquito Multiplication
Easy3
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Easiest Problem Is This One
Easy3
Brute force, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
On-Line Banking
Easy3
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Soccer Tournament
Easy3
Implementation, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Read the Chessboard
Easy3
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bridge Hands
Easy3
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Complicated Route
Easy3
Implementation, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Too Much Water
Easy3
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ball Bearings
Easy3
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hardware
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Goldbach's Conjecture
Easy3
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Add Backward Numbers
Easy3
Math, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Next Year with Distinct Digits
Easy3
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Chances of Winning
Easy3
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Don't pass me the ball!
Easy3
Combinatorics, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Aromatic Numbers
Easy3
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Absolutely Acidic
Easy3
Array, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Mouse Journey
Easy3
Dynamic programming, Matrix+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Who Has Seen the Wind
Easy3
Math, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Up and Down
Easy3
Simulation, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Punchy
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Global Warming
Easy3
String matching, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Huffman Encoding
Easy3
Trie, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Signage
Easy3
String, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cool Numbers
Easy3
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
GPS Text Entry
Easy3
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cell-Phone Messaging
Easy3
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Maternity
Easy3
Implementation, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
RSA Numbers
Easy3
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Returning Home
Easy3
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fix-Free Check
Easy3
String, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
TopYodeller
Easy3
Array, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Picture Perfect
Easy3
Math, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Snakes and Ladders
Easy3
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Poetry
Easy3
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
BFed
Easy3
Simulation, Stack+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Students' Council Breakfast
Easy3
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Keeping Score
Easy3
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Numbers That Read the Same Upside Down
Easy3
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Slot Machines
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Babbling Brooks
Easy3
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Surfing
Easy3
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Card Game
Easy3
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Censor
Easy3
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sentences
Easy3
Brute force, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dynamic Dictionary Coding
Easy3
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Deficient, Perfect, and Abundant
Easy3
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Train Swapping
Easy3
Array, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Trimmed and Corrected Mean
Easy3
Sorting, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Arithmetic Sequence
Easy3
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hobbiton Farms
Easy3
Geometry, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hand Detection
Easy3
Implementation, Hash map
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Guessing Game I
Easy3
Implementation, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Millennium
Easy3
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rectangle
Easy3
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Milk and Honey
Easy3
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Making shortest-path test data
Easy3
Implementation, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Graph that exceeds Dijkstra's counter
Easy3
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Class
Easy3
Implementation, Matrix+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mõttemeister
Easy3
Implementation, Array+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Word Problem (TEKSTER)
Easy3
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Carpets
Easy3
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Harmony: Parallel Fifths
Easy3
Implementation, Array+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Harmony
Easy3
Implementation, Brute force+2
No attempts yet
Time limit
7s
Memory limit
1024 MB
Judgeable
Aliens' Socks
Easy3
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
S-TreesGiven an S-tree's variable ordering and terminal labels, evaluate the Boolean function for each supplied variable assignment.	Easy3	TreeSimulation+1	No attempts yet	1s	128 MB	Judgeable
Four QuartersFor each round count from 1 to 20, compute the probability that A wins, B wins, or the game ties after that many rounds of this four-coin game.	Easy3	ProbabilityDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
The Drunken JailerA jailer toggles the doors of cells that are multiples of k in round k; count how many doors end up open after n rounds.	Easy3	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Bode PlotGiven source voltage, resistance, capacitance, and several angular frequencies, compute the resistor voltage magnitude from the RC low-pass circuit equations.	Easy3	MathSimulation+2	No attempts yet	1s	128 MB	Judgeable
Set MeGiven tableaus of Set cards, print each tableau and then every triple of cards that forms a valid set, in index order.	Easy3	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
Digital RootGiven positive integers up to 1000 digits, each line until a terminating 0, print the digital root of each number.	Easy3	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Clock PatienceSimulate Clock Patience on several decks: deal cards into 13 piles, flip cards following rank-to-pile moves, and report how many cards were exposed and the last card.	Easy3	SimulationArray+1	No attempts yet	1s	128 MB	Judgeable
FloppiesCompute the number of floppies by applying fixed roundings for compression, uuencoding, 30000-line splitting, and recompression.	Easy3	MathSimulation+1	No attempts yet	1s	128 MB	Judgeable
Transaction ProcessingRead ledger accounts and transaction entries, then print an exception report for any transaction whose debits and credits do not sum to zero.	Easy3	ImplementationHash map+2	No attempts yet	1s	128 MB	Judgeable
Circle Through Three PointsFor each line of three points, compute the circle through them and print its center-radius and general equations with signs adjusted.	Easy3	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Adam's GenesProcess cloning requests in order, tracking each clone's accumulated genes and reporting whether it is consistent and safe, disconnected from Adam, or doubly mutated.	Easy3	Hash mapSimulation+2	No attempts yet	1s	128 MB	Judgeable
Prime CutsFor each N and C, build the primes from 1 to N and print the middle C2 or C2-1 of them, or the whole list if that many do not exist.	Easy3	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Uniform GeneratorFor each pair STEP and MOD, decide whether seed(x+1) = (seed(x) + STEP) mod MOD cycles through all MOD values, which holds exactly when gcd(STEP, MOD) = 1.	Easy3	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Unix ls Column FormattingSort filenames by ASCII value and lay them out in column-major order with fixed-width padding, as few rows as fit in 60 characters.	Easy3	SortingImplementation+2	No attempts yet	1s	128 MB	Judgeable
PalindromesFor each string, decide whether it reads the same backward and whether replacing each character by its mirror and reversing gives the same string.	Easy3	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Factorial FrequenciesRead n values until a terminating 0, and for each n count how many times each digit 0 through 9 appears in the decimal representation of n! (n up to 366), printing the counts in a fixed two-line format.	Easy3	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
Evaluating Simple C ExpressionsEvaluate a sequence of simple C expressions with +, -, and prefix or postfix ++/--, printing the expression value and the final values of used variables.	Easy3	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Shipping RoutesGiven warehouses and bidirectional shipping legs, answer each request with the cheapest cost, which is shipment size times the minimum number of legs times 100, or report no route.	Easy3	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Donghyeok PizzaGiven a circular table of radius r and a rectangular pizza w by l, decide whether the rectangle fits inside the circle.	Easy3	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Kilometers to MilesConvert each kilometer value to miles by writing it in Zeckendorf Fibonacci form, dropping the lowest bit, and re-evaluating.	Easy3	MathGreedy+2	No attempts yet	1s	128 MB	Judgeable
Black and White PaintingCount the 8x8 blocks inside an n by m checkerboard whose bottom-right square is white, given the color of the painting's bottom-right corner.	Easy3	MathCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Ambiguous PermutationsFor each permutation, decide whether it equals its own inverse, meaning position of value i equals the value at position i.	Easy3	ArrayImplementation	No attempts yet	1s	128 MB	Judgeable
Help the problem setterFor each test case, read a binary search tree on labels 1..n and print each node's frequency, computed bottom-up as 1 plus the sum of the frequencies of all its proper descendants.	Easy3	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
EdgeGiven a string of A (clockwise) and V (counter-clockwise) turns, emit PostScript line commands tracing a unit-step path from a fixed start point.	Easy3	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Genetic CodePrint the first n characters of the infinite square-free sequence generated by the substitution N→NOP, O→NP, P→O.	Easy3	StringRecursion	No attempts yet	1s	128 MB	Judgeable
SubsequenceFor each line of input, decide whether the first string is a subsequence of the second, printing Yes or No.	Easy3	Two pointersString+2	No attempts yet	1s	128 MB	Judgeable
Polygon Programming with EaseGiven the midpoints of the edges of a polygon with an odd number of vertices, recover the original vertex coordinates using an alternating sum and forward substitution.	Easy3	MathGeometry+2	No attempts yet	1s	128 MB	Judgeable
Paths on a GridCount monotone lattice paths from the lower-left to the upper-right of an n by m grid.	Easy3	CombinatoricsMath	No attempts yet	1s	128 MB	Judgeable
Average is not Fast Enough!Parse each team's section times in h:mm:ss form, sum them, and print the average seconds per kilometer rounded to the nearest second, or a dash if any runner was disqualified.	Easy3	ImplementationString+2	No attempts yet	1s	128 MB	Judgeable
HTMLRender an HTML fragment of plain text with <br> and <hr> tags, wrapping lines at 80 characters.	Easy3	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Artificial Intelligence?Given a word problem stating two of power, voltage, and current with optional metric prefixes, compute the missing quantity using P = U * I.	Easy3	StringMath+1	No attempts yet	1s	128 MB	Judgeable
Balancing Bank AccountsGiven transactions among travelers, compute each person's net balance and print the canonical chain of payments using prefix sums.	Easy3	Prefix sumHash map+1	No attempts yet	1s	128 MB	Judgeable
Error CorrectionFor each square 0/1 matrix, report OK if every row and column sum is even, the single bit that fixes the parity if exactly one row and one column are odd, or Corrupt otherwise.	Easy3	ImplementationArray+2	No attempts yet	1s	128 MB	Judgeable
GlobetrotterRead a list of cities with latitudes and longitudes, then for each query print the great-circle distance between two cities rounded to the nearest km.	Easy3	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Circumference of a CircleFor each line of three non-collinear points, compute the perimeter of the circle passing through them, rounded to two decimals.	Easy3	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Mosquito MultiplicationSimulate weekly mosquito stages (eggs become larvae, larvae become pupae, pupae become adults) with floor divisions and report the adult count after N Sundays.	Easy3	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
The Easiest Problem Is This OneFor each positive integer N up to 100000, find the smallest multiplier p greater than 10 such that N and N*p have the same decimal digit sum.	Easy3	Brute forceMath+2	No attempts yet	1s	128 MB	Judgeable
On-Line BankingSimulate a stream of bank commands (create, deposit, withdraw, transfer) over many scenarios and print the result of each request.	Easy3	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Soccer TournamentRead team lists and played games, then print a result grid and a standings table sorted by points, goal difference, goals, wins, and reverse input order.	Easy3	ImplementationSorting	No attempts yet	1s	128 MB	Judgeable
Read the ChessboardGiven an ASCII-art chessboard, list each side's pieces in standard notation, grouped by type in a fixed order and sorted by position rules.	Easy3	ImplementationString+2	No attempts yet	1s	128 MB	Judgeable
Bridge HandsDeal a 52-card deck to four bridge players from a given dealer, sort each 13-card hand by suit and rank, and print the hands in a fixed card-table format.	Easy3	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Complicated RouteParse a route of step counts in eight compass directions, sum the displacement, and print the final point and its distance from the origin to three decimals.	Easy3	ImplementationMath+2	No attempts yet	1s	128 MB	Judgeable
Too Much WaterGiven a property point, compute the hour when the growing semicircle centered at the origin first covers it, using the fixed 50 square meters per hour rate.	Easy3	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Ball BearingsGiven the inner diameter of an outer ring, the ball diameter, and the minimum gap between neighboring balls, find the maximum number of balls that fit.	Easy3	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
HardwareExpand each house-number order into individual numbers, count how many times each digit 0-9 appears, and print the per-digit totals plus the grand total.	Easy3	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Goldbach's ConjectureFor each even n below 2^15, count the unordered pairs of primes that sum to n, stopping at a terminating 0.	Easy3	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Add Backward NumbersAdd two numbers whose digits are given in reverse order, printing the sum with its digits also reversed and no leading zeroes.	Easy3	MathString+2	No attempts yet	1s	128 MB	Judgeable
The Next Year with Distinct DigitsGiven a year Y, print the smallest year greater than Y whose decimal digits are all distinct.	Easy3	Brute forceImplementation	No attempts yet	1s	128 MB	Judgeable
Chances of WinningGiven results of some games among four teams, count the outcomes of the remaining games where team T ends with strictly more points than every other team.	Easy3	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
Don't pass me the ball!Given the scorer's jersey number J, count the ordered increasing 4-tuples of distinct jersey numbers ending at J.	Easy3	CombinatoricsMath	No attempts yet	2s	512 MB	Judgeable
Aromatic NumbersGiven a string alternating Arabic digits and Roman numeral letters, sum each digit times its Roman value, subtracting a pair when the next Roman value is larger.	Easy3	StringImplementation+1	No attempts yet	2s	512 MB	Judgeable
Absolutely AcidicCount the frequency of readings in the range 1 to 1000, then apply tie-breaking rules to find which two readings to subtract.	Easy3	ArrayImplementation+1	No attempts yet	2s	512 MB	Judgeable
Mouse JourneyCount monotone right/down paths on an R by C grid from (1,1) to (R,C) that avoid K blocked cat cells.	Easy3	Dynamic programmingMatrix+1	No attempts yet	2s	512 MB	Judgeable
Who Has Seen the WindGiven humidity h and a time limit M, evaluate the quartic altitude formula hour by hour and report the first hour the balloon's altitude drops to zero or below.	Easy3	MathSimulation+2	No attempts yet	2s	512 MB	Judgeable
Up and DownTwo walkers repeat a forward/backward step cycle; after s steps, report whose distance from the start is greater, or Tied.	Easy3	SimulationMath+2	No attempts yet	2s	512 MB	Judgeable
PunchySimulate a tiny two-variable language, running the given instructions in order until a stop opcode, and print each requested variable value.	Easy3	SimulationImplementation+1	No attempts yet	2s	512 MB	Judgeable
Global WarmingGiven a sequence of temperatures, find the length of the shortest period of the sequence of consecutive differences, allowing the final repetition to be truncated.	Easy3	String matchingBrute force+2	No attempts yet	2s	512 MB	Judgeable
Huffman EncodingGiven prefix-free binary codes for up to 20 letters, decode a binary string of at most 250 digits back into the original letters.	Easy3	TrieString+2	No attempts yet	2s	512 MB	Judgeable
SignageGiven a sign width, lay out a fixed sentence into lines, justifying each line so spaces are spread as evenly as possible, and print dots for spaces.	Easy3	StringSimulation+2	No attempts yet	1s	128 MB	Judgeable
Cool NumbersCount integers in [a, b] that are both a perfect square and a perfect cube, meaning perfect sixth powers.	Easy3	MathNumber theory+1	No attempts yet	1s	128 MB	Judgeable
GPS Text EntryGiven a fixed 5x6 letter grid, compute the total cursor moves to type a string starting from 'A' and then reach 'enter'.	Easy3	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Cell-Phone MessagingGiven words, compute the typing time on a phone keypad where each press takes 1 second and switching between letters on the same key adds a 2-second pause.	Easy3	ImplementationString+2	No attempts yet	1s	128 MB	Judgeable
MaternityGiven the two alleles each parent carries for five genes, decide for each baby whether its five visible traits could result from that pairing.	Easy3	ImplementationCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
RSA NumbersCount how many integers in an inclusive range below 1000 have exactly four divisors, then print the count in a fixed sentence.	Easy3	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Returning HomeReverse a short list of turn directions and street names, flipping each left or right turn, to produce the route from school back home.	Easy3	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Fix-Free CheckFor each triple of words, decide whether no word is a prefix or suffix of another, printing Yes or No.	Easy3	StringBrute force+2	No attempts yet	1s	128 MB	Judgeable
TopYodellerCompute each yodeller's cumulative score after every round, find who ends with the highest total, and report their worst rank.	Easy3	ArraySimulation+1	No attempts yet	1s	128 MB	Judgeable
Picture PerfectFor each C, find the factor pair (W, H) with W*H = C closest to a square, and report the smallest perimeter along with W and H.	Easy3	MathBrute force+2	No attempts yet	1s	128 MB	Judgeable
Snakes and LaddersSimulate a Snakes and Ladders game with a fixed 100-square board, applying three given ladders and three given snakes after each dice roll until the piece reaches 100 or the player quits.	Easy3	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
PoetryFor each four-line verse, extract the last syllable of the final word on every line and print which rhyme scheme it matches.	Easy3	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
BFedInterpret a Brainfuck program read from stdin up to '#', supporting the seven pointer, arithmetic, loop, and output commands on a 30000-cell byte tape.	Easy3	SimulationStack+2	No attempts yet	1s	128 MB	Judgeable
The Students' Council BreakfastGiven four ticket prices and a target amount, list every non-negative count combination that hits the target, count them, and report the fewest tickets needed.	Easy3	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
Keeping ScoreParse a 13-card hand grouped by suit, score high cards and short suits, and print each suit with points right-aligned in a fixed table.	Easy3	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
Numbers That Read the Same Upside DownCount how many integers in the interval [m, n] stay the same when rotated 180 degrees, using the digit map 0, 1, 8, 6, 9.	Easy3	MathImplementation+2	No attempts yet	1s	128 MB	Judgeable
Slot MachinesSimulate a gambler who cycles through three slot machines with fixed payout periods and stops when she runs out of quarters, and report the total number of plays.	Easy3	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Babbling BrooksSimulate a sequence of splits and joins on a list of streams and print the resulting flows after each split divides flow by a percentage and each join merges neighbors.	Easy3	ImplementationSimulation+1	No attempts yet	1s	128 MB	Judgeable
SurfingParse links out of HTML pages, print each link, then answer reachability queries between pages.	Easy3	GraphDFS+1	No attempts yet	1s	128 MB	Judgeable
Card GameSimulate a 52-card game where players alternate turning cards; award points when a high card is followed by enough non-high cards, then print each score.	Easy3	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
CensorRead n lines of space-separated words and replace every word of exactly four letters with ****, printing a blank line between consecutive output lines.	Easy3	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
SentencesGiven lists of subjects, verbs, and objects, print every subject-verb-object sentence in alphabetical order, with a blank line between datasets.	Easy3	Brute forceSorting+2	No attempts yet	1s	128 MB	Judgeable
Dynamic Dictionary CodingCompress each text set by replacing repeated words with their 1-based dictionary positions, leaving first occurrences unchanged, and preserve all spacing.	Easy3	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Deficient, Perfect, and AbundantFor each integer, sum its proper divisors and classify it as deficient, perfect, or abundant.	Easy3	MathNumber theory+1	No attempts yet	1s	128 MB	Judgeable
Train SwappingFor each test case, count the inversions of a permutation of 1..L, the minimum number of adjacent swaps needed to sort the train.	Easy3	ArraySorting+2	No attempts yet	1s	128 MB	Judgeable
Trimmed and Corrected MeanGiven N judge scores and an integer K, sort the scores, then output the trimmed mean that drops K from each end and the corrected mean that replaces those extremes with the nearest kept value, both rounded to two decimals.	Easy3	SortingPrefix sum+2	No attempts yet	1s	256 MB	Judgeable
Arithmetic SequenceGiven a sequence, decide whether consecutive differences are equal and, if so, print the next five terms in the exact required format.	Easy3	ImplementationMath+1	No attempts yet	1s	128 MB	Judgeable
Hobbiton FarmsFor each test case, decide whether a circle and an axis-aligned rectangle share at least one point.	Easy3	GeometryImplementation+1	No attempts yet	1s	128 MB	Judgeable
Hand DetectionFor each five-card hand, check whether all ten pairwise value differences are distinct and whether the five suits are all different.	Easy3	ImplementationHash map	No attempts yet	1s	128 MB	Judgeable
Guessing Game ICompare a 4-digit secret and a guess digit by digit, count exact-position matches as circles and remaining cross-position matches as squares, with duplicates matched once.	Easy3	ImplementationHash map+2	No attempts yet	1s	128 MB	Judgeable
MillenniumGiven a birthdate in a fictional 10-month calendar with alternating 19 and 20 day months, find days until year 1000, month 1, day 1.	Easy3	MathImplementation+2	No attempts yet	1s	128 MB	Judgeable
RectangleRepeatedly cut the largest possible square from an n by m rectangle and count how many squares result.	Easy3	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
Milk and HoneyEach field holds either cows up to its cow limit or bees up to its bee limit; assign each field one animal type to maximize happiness from milk and honey.	Easy3	GreedySorting+2	No attempts yet	1s	1024 MB	Judgeable
Making shortest-path test dataPrint the prescribed shortest-path test graph: a chain with a computed number of self-loops at vertex 0, plus Q queries from V-1 to 0.	Easy3	ImplementationGraph+2	No attempts yet	1s	128 MB	Judgeable
Graph that exceeds Dijkstra's counterPrint the exact constructed directed weighted graph that makes Floyd-Warshall finish while the lazy-deletion Dijkstra times out on one query.	Easy3	GraphShortest path+1	No attempts yet	1s	128 MB	Judgeable
ClassGiven a grid of digits, sum each cell's average absolute difference from its up to four orthogonal neighbors, and print the total with four decimals.	Easy3	ImplementationMatrix+2	No attempts yet	1s	1024 MB	Judgeable
MõttemeisterGiven a secret four-digit number and N guesses, print for each guess the count of correct digits (A) and the count of digits in the correct position (B).	Easy3	ImplementationArray+2	No attempts yet	1s	1024 MB	Judgeable
Word Problem (TEKSTER)Parse variable values embedded in a word problem, then evaluate the student's step-by-step arithmetic and print the last step's result.	Easy3	ImplementationString+2	No attempts yet	1s	1024 MB	Judgeable
CarpetsGiven up to three axis-aligned rectangles, find the total area of their union.	Easy3	GeometryImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Harmony: Parallel FifthsGiven N pairs of simultaneous two-voice pitches, list every position i where the voices form a perfect fifth (interval 5 mod 12) at both i and i+1 and both voices move.	Easy3	ImplementationArray+2	No attempts yet	3s	1024 MB	Judgeable
HarmonyGiven K voices over N note rows, list every pair of consecutive rows and voice pair that forms a parallel fifth (both voices move and stay 7 semitones apart mod 12).	Easy3	ImplementationBrute force+2	No attempts yet	7s	1024 MB	Judgeable
Aliens' SocksFind the minimum number of socks to draw so that at least k of one color are guaranteed, given the counts per color.	Easy3	GreedyMath+1	No attempts yet	1s	1024 MB	Judgeable