Problems
Pick a problem and write your solution in the built-in editor. The judge runs it against real test cases while you watch, and the wider archive is open to read whenever you like.
Total results2,994 problems
| Title | Level | Topics | Solved | Time limit | Memory limit | Judge |
|---|---|---|---|---|---|---|
| Shuttle RunGiven the total distance Jihun can run, report which of the 5 m cone intervals he collapses in. | Easy3 | MathImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Look for the Winner!Given votes counted in order, report the earliest prefix after which one candidate's lead cannot be overtaken from remaining votes, or TIE. | Easy3 | ArraySimulation+1 | No attempts yet | 2s | 512 MB | Judgeable |
| TrucksTrucks cross a one-lane bridge in order under a weight limit; find the earliest time all have finished. | Easy3 | QueueSimulation | No attempts yet | 1s | 512 MB | Judgeable |
| Quality of Check DigitsGiven a 10x10 operation table, count how many of the 10000 four-digit basic IDs let a single-digit change or an adjacent swap pass the check digit test. | Easy3 | ImplementationBrute force+1 | No attempts yet | 1s | 512 MB | Judgeable |
| Course registrationGiven a click log of student numbers and K seats, keep each student's last click, then print the first K distinct students in that order. | Easy3 | QueueHash map+1 | No attempts yet | 1s | 256 MB | Judgeable |
| Turing machine halting in ten stepsSimulate a Turing machine for at most 10 steps on each query tape and report whether it reaches the halting state. | Easy3 | SimulationImplementation+2 | No attempts yet | 1s | 256 MB | Judgeable |
| RobotFollow TURN and MOVE commands from the origin facing east, print the final coordinates, or -1 if any move leaves the square. | Easy3 | SimulationImplementation+1 | No attempts yet | 1s | 512 MB | Judgeable |
| Strategy GameDistribute J times R point values to players in turn order, sum each player's points, and find the highest scorer, breaking ties by last move. | Easy3 | ArraySimulation | No attempts yet | 1s | 512 MB | Judgeable |
| The Lap Where the Backmarker Falls BehindGiven lap times X (fast) and Y (slow), find the leader's lap number when the leader first laps the slowest driver. | Easy3 | MathSimulation | No attempts yet | 2s | 512 MB | Judgeable |
| Digital Biochemical CircuitGiven an N-by-P table of bits, count the runs of consecutive 1s in each column whose length is at least C. | Easy3 | MatrixSimulation+1 | No attempts yet | 1s | 512 MB | Judgeable |
| Collector RobotSimulate a robot moving on a grid with pillars, turning and stepping according to a given instruction string, and count the distinct stickers it visits. | Easy3 | SimulationImplementation | No attempts yet | 2s | 512 MB | Judgeable |
| Peaks of a Musical LoopCount local maxima and minima in a circular sequence of samples where consecutive values differ and the first and last differ. | Easy3 | ImplementationArray+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Hawk EyesGiven a sequence of cup swaps among four positions, track where the small ball (initially at position 1) and big ball (initially at position 4) end up. | Easy3 | SimulationImplementation | No attempts yet | 1s | 512 MB | Judgeable |
| Averages in PlaceGiven N, print the one fixed N x N table whose row and column averages each land inside their own row and column, with -1 for N=2. | Easy3 | ImplementationMath+2 | No attempts yet | 1s | 64 MB | Judgeable |
| The Calculus of AdaGiven n values of a polynomial at evenly spaced inputs, find the degree of the minimal-degree polynomial and its value at the next input using finite differences. | Easy3 | MathImplementation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Hunt the RabbitFor each hidden rabbit position, print the sequence of envelope numbers a lower-middle binary search opens until it finds the rabbit. | Easy3 | Binary searchSimulation | No attempts yet | 2s | 512 MB | Judgeable |
| Hyper Rock-Scissors-PaperGiven each player's gesture in a 15-gesture rock-paper-scissors variant, find the single gesture that beats at least one shown gesture and loses to none, or report Draw. | Easy3 | ImplementationArray+2 | No attempts yet | 8s | 512 MB | Judgeable |
| Blackjack DealerSimulate the dealer's blackjack hand: report blackjack, bust, or the final score after the dealer plays by fixed rules. | Easy3 | SimulationImplementation | No attempts yet | 8s | 512 MB | Judgeable |
| ImenaSplit a book's text into N sentences and count, for each, how many words are names (uppercase first letter, lowercase rest). | Easy3 | StringImplementation+1 | No attempts yet | 1s | 32 MB | Judgeable |
| Dudu of EnglishApply seven ordered text transformations (lowercase, of-word replacement, vowel deletion, punctuation removal, line join, space condense, 20-char reflow) to translate English into Dudu's dialect. | Easy3 | StringImplementation+1 | No attempts yet | 2s | 512 MB | Judgeable |
| ReversalApply M substring reversals to a string of up to 2.5 million characters and print the final result. | Easy3 | StringImplementation+1 | No attempts yet | 1s | 256 MB | Judgeable |
| TriangleRecursively subdivide a triangle into three corner triangles N-1 times and print the resulting ASCII fractal. | Easy3 | Divide and conquerRecursion+1 | No attempts yet | 1s | 64 MB | Judgeable |
| The Crow's Last AttackSimulate a crow that attacks around a circular line of enemies, reversing on kills, and report which enemy takes the last attack. | Easy3 | SimulationImplementation | No attempts yet | 2s | 512 MB | Judgeable |
| Ticket machine keyboardGiven destination names and a pressed prefix, mark on a 4x8 grid every letter that can immediately follow the prefix in some name. | Easy3 | StringSimulation+2 | No attempts yet | 1s | 32 MB | Judgeable |
| Counting Sheep (Small)Track which digits 0 to 9 appear as Bleatrix counts multiples of N, and report the last multiple or INSOMNIA if digit 9 never completes. | Easy3 | SimulationImplementation+1 | No attempts yet | 5s | 512 MB | Judgeable |
| Baskin-Robbins 31Given n games with parameters j and m, compute how many turns each lasts and report the earliest game with the minimum turn count. | Easy3 | MathImplementation+2 | No attempts yet | 2s | 256 MB | Judgeable |
| Hoof, Paper, Scissors (Bronze)Given a sequence of pairs of gesture numbers, try all six ways to map numbers 1,2,3 to hoof, paper, scissors and report the largest number of games the first cow wins under any mapping. | Easy3 | Brute forceSimulation+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Why Did the Cow Cross the Road 1Given observations of which side of the road each of 10 cows stands on, count how many times a cow changes sides between consecutive observations of that cow. | Easy3 | ArrayImplementation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Why Did the Cow Cross the Road 3Given each cow's arrival and inspection time, find the earliest time all cows finish entering when inspected one at a time in arrival order. | Easy3 | SortingSimulation | No attempts yet | 2s | 512 MB | Judgeable |
| The Lost CowGiven start x and target y on a number line, simulate a doubling zig-zag search and report the total distance traveled until y is reached. | Easy3 | MathSimulation | No attempts yet | 2s | 512 MB | Judgeable |
| Kim's DinerMaintain a list of pending orders under append, sort by (time, table), and delete-by-table commands, printing the list after each query. | Easy3 | SimulationSorting+2 | No attempts yet | 2s | 256 MB | Judgeable |
| High-End ArtworkStamps are pressed onto a paper in a given order; later presses overwrite earlier ones. Print the final grid, using '.' for untouched cells. | Easy3 | SimulationArray+1 | No attempts yet | 4s | 512 MB | Judgeable |
| Mun, Hong, AnEach secretary adds one step to every stone in one direction from the start. Count total steps per stone modulo 3, then split P by the final blue, red, and green counts. | Easy3 | ImplementationPrefix sum+2 | No attempts yet | 2s | 256 MB | Judgeable |
| Sickly YeongjeongMap each symptom to its medicine name, then for every query list output the matching medicines in order or YOU DIED if any symptom is untreatable. | Easy3 | Hash mapImplementation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Ttakji GameFor each of N rounds, compare two cards by counting stars, then circles, then squares, then triangles, and print which player wins or a draw. | Easy3 | ImplementationArray+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Coke Drinking ContestGiven N entrants who each drink A mL per second with fixed drinking and resting periods, find when the first entrant finishes K mL. | Easy3 | MathSimulation+1 | No attempts yet | 1s | 512 MB | Judgeable |
| Reverse NonogramGiven a solved nonogram grid of '.' and 'X', print the run-length clues for every row and then every column. | Easy3 | ImplementationSimulation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Tracking Fake NewsModel a story spreading through a social network where each person reposts only if a weighted sum of the story's categories equals their target. | Easy3 | GraphBFS+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Alphabet Cake (Large)Fill every blank cell in a grid so each distinct letter occupies one axis-aligned rectangle, following the prescribed row-by-row expansion rule. | Easy3 | ImplementationSimulation+1 | No attempts yet | 5s | 512 MB | Judgeable |
| Happy NumberDecide whether repeatedly summing the squares of a number's decimal digits ever reaches 1. | Easy3 | SimulationHash map+1 | No attempts yet | 0.2s | 512 MB | Judgeable |
| Cezar's BlackjackGiven the values of N drawn cards summing to at most 21, decide whether to draw again based on how many remaining cards exceed the gap to 21. | Easy3 | ImplementationMath+2 | No attempts yet | 1s | 64 MB | Judgeable |
| Is Everybody Appy?Given each kid's ranked list of apps from oldest to youngest, assign each kid the highest-ranked app not already taken by an older kid. | Easy3 | Hash mapGreedy+2 | No attempts yet | 2s | 512 MB | Judgeable |
| DRM MessagesSplit a string in half, rotate each half by its character sum, then merge the halves by rotating one half with the other's values. | Easy3 | StringImplementation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Game of ThrownsTrack a token around a circle of children through clockwise or counterclockwise throws, undoing the last m throws on command. | Easy3 | StackSimulation+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Lights in the MorningGiven each light's first green time and green/red cycle, decide whether a car driving 1 km per minute reaches every light during green. | Easy3 | ImplementationMath+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Golf CroquetSimulate a golf croquet doubles game from a stroke record and report the score and standing once a team reaches 7 points. | Easy3 | SimulationImplementation+1 | No attempts yet | 2s | 512 MB | Judgeable |
| FitnessSimulate moves around 8 circularly numbered stations and print the visited sequence, marking it reject if fewer than 5 distinct stations appear or any station repeats. | Easy3 | SimulationImplementation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Musical ChairsSimulate musical chairs: each round every remaining player shifts M seats clockwise, the player at seat S is eliminated, and seats are renumbered until R rounds pass. | Easy3 | SimulationImplementation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| League TablesGiven each team's current record and a list of match results, update the records and print the table sorted by points, goal difference, goals scored, then name. | Easy3 | ImplementationSorting+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Another Brick in the WallSimulate laying bricks in pile order across h layers of width w, and report whether every layer fills exactly before the pile runs out. | Easy3 | SimulationImplementation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Name CompatibilityInterleave two equal-length names letter by letter, replace each letter with its stroke count, then repeatedly sum adjacent digits (keeping the ones digit) until two remain. | Easy3 | ImplementationSimulation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Bank Card VerifierEach test case gives a 16-digit card number as four 4-digit groups; apply the Luhn checksum rule and print Yes if the total is a multiple of 10, otherwise No. | Easy3 | ImplementationString+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Aron's Place in LineGiven the shirt colors of people in line, where each maximal run of equal colors is one group, find the position Aron occupies at the back. | Easy3 | ImplementationString+2 | No attempts yet | 1s | 32 MB | Judgeable |
| Vera and ABCDEGiven a string of N letters from A to E, render the 5x3 pattern for each letter side by side and print the resulting 5 rows of 3N characters. | Easy3 | ImplementationString+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Poker Card CombinationsGiven six card ranks, count how often each rank appears and print which of the nine named poker combinations the hand forms. | Easy3 | Hash mapImplementation+1 | No attempts yet | 1s | 512 MB | Judgeable |
| Äventyr 1On a path 1 to N, vertices become active over time; after each activation, answer the distance from a query vertex to the nearest active vertex, or -1 if none exists yet. | Easy3 | ArraySorting+2 | No attempts yet | 1s | 256 MB | Judgeable |
| Accepted ratioGiven a submission log, ignore the administrator, count solvers and the rejections each made before their first accepted submission, then print the accepted ratio with 10 decimals. | Easy3 | ImplementationHash map+2 | No attempts yet | 2s | 512 MB | Judgeable |
| BeondegiGiven A players in a circle and a chant pattern by rounds, find who makes the T-th call of a chosen word (ppeon or degi), counting only that word. | Easy3 | MathImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Round and Round SnailA snail walks a clockwise square spiral from the origin, one cell per second; given n seconds, print its coordinates. | Easy3 | ImplementationSimulation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| A/B to 2000 decimal placesPrint A/B with exactly 2000 digits after the decimal point, truncating rather than rounding. | Easy3 | MathImplementation+1 | No attempts yet | 0.5s | 512 MB | Judgeable |
| RouterSimulate a buffer of size N: packets arrive in order, 0 means one is handled and removed from the front, and a packet arriving with the buffer full is dropped. | Easy3 | QueueSimulation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Stroop EffectGiven sequences of two-digit word-ink codes, check whether each sequence satisfies the counts and the no-three-in-a-row rule for a valid Stroop test. | Easy3 | ImplementationSimulation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Baby Sukhwan Tururu TuruFind the N-th word of a repeating song whose tururu runs grow by one extra ru each repetition, with long runs printed in a compressed form. | Easy3 | ImplementationMath+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Binary Search TreeInsert a sequence of integers into a BST and output the depth of each inserted node. | Easy3 | TreeRecursion+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Lie DetectorEach detector vouches for the previous one except the last, which is always right. Walk the chain backwards and flip the answer once per LIE report. | Easy3 | ImplementationSimulation | No attempts yet | 1s | 512 MB | Judgeable |
| ICPCGiven the four goal counts from two-legged finals, apply aggregate scores and the away goals tiebreak to name the winner or output Penalty. | Easy3 | ImplementationMath+1 | No attempts yet | 2s | 512 MB | Judgeable |
| TurnaroundsGiven the seconds when each team scored, report how many points fell in the first half and how many times the lead changed from strictly behind to strictly ahead. | Easy3 | ImplementationSimulation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Sugoroku and PiecesMove pieces forward one square on a 2019-square board, but block moves onto the goal or an occupied square, then report each piece's final position. | Easy3 | SimulationArray+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Slimming PlanSimulate daily weight changes from the repeating D-day plan and report the day the weight reaches T, or output -1 if it never does. | Easy3 | SimulationArray+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Cellphone Text CompressionFor each of N strings, output its run-length encoding: each maximal run of identical characters as a count followed by the character. | Easy3 | StringImplementation+1 | No attempts yet | 1s | 512 MB | Judgeable |
| FlipperStart with the grid 1 2 / 3 4 and apply a sequence of horizontal (H) and vertical (V) flips, then print the final grid. | Easy3 | SimulationImplementation+1 | No attempts yet | 1s | 512 MB | Judgeable |
| Shell GameGiven N shell swaps and Elsie's guess after each swap, find the highest number of correct guesses she could make over all possible starting positions of the pebble. | Easy3 | SimulationBrute force+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Word ClockConvert an hour and minute into the words a word clock shows, using past or to and special phrases for 0, 15, 30, and 45 minutes. | Easy3 | ImplementationString+2 | No attempts yet | 0.5s | 512 MB | Judgeable |
| 3-Minute GraphSubmit source code to a microwave judge: a program that fails to compile resets the timer with a fresh graph, a compiling one serves it, so the program must compile after roughly three minutes of runtime. | Easy3 | ImplementationSimulation | No attempts yet | 1s | 512 MB | Judgeable |
| Total Number of CountsGiven N bills and bundle size M, repeatedly count items and group them into bundles of M until no bundle can form, then print the total number of counts. | Easy3 | MathSimulation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Phone Number CompatibilityInterleave two 8-digit phone numbers, repeatedly replace adjacent pairs by the units digit of their sum until two digits remain, and print the score with leading zeros. | Easy3 | ImplementationSimulation+1 | No attempts yet | 2s | 256 MB | Judgeable |
| Good Day Bad DayGiven a two-state Markov chain's transition probabilities and a starting mood, compute the probability of each mood N days later and print each scaled by 1000. | Easy3 | ProbabilityDynamic programming+2 | No attempts yet | 1s | 256 MB | Judgeable |
| I AM IRONMANSimulate N games: look up each opponent in a win/loss table, add W or subtract L (floored at 0), and report whether the score ever reaches G. | Easy3 | SimulationImplementation+2 | No attempts yet | 1s | 256 MB | Judgeable |
| I am GrootGiven trunk length L and ratio R, branches double each level while length becomes floor(prev*R/100), stopping when a level's length is 5 or less; sum all branch lengths. | Easy3 | SimulationImplementation+1 | No attempts yet | 1s | 256 MB | Judgeable |
| Only Three!Count how many length-3 windows of a digit string are strictly increasing and are not extended to a run of four or more consecutive digits. | Easy3 | StringImplementation+2 | No attempts yet | 1s | 256 MB | Judgeable |
| Worm ReproductionTrack a worm population over N years where each worm splits yearly and dies after 3 or 4 splits depending on its birth year's parity. | Easy3 | SimulationImplementation | No attempts yet | 1s | 256 MB | Judgeable |
| What Does Milk Say When It Falls Over?Given a grid of ASCII art characters, rotate it 90 degrees to the left, mapping each character to its rotated counterpart. | Easy3 | ImplementationMatrix+2 | No attempts yet | 1s | 1024 MB | Judgeable |
| Star FruitGiven summer length N, growth time T, C plots, and price P, compute the maximum money earnable by planting and replanting each plot as often as possible. | Easy3 | GreedyMath+2 | No attempts yet | 1s | 256 MB | Judgeable |
| GerrymanderingSum precinct votes into districts, find each district's winner, compute lost and excess wasted votes per party, then output the overall efficiency gap. | Easy3 | ImplementationMath+2 | No attempts yet | 2s | 1024 MB | Judgeable |
| Beer BillParse each bill line as either an item price with optional bars or a bars-only rake line, then print the total (beer at 42) rounded up to a multiple of 10 in the N,- format. | Easy3 | ImplementationString+2 | No attempts yet | 2s | 512 MB | Judgeable |
| ClockGiven a clock time, compute the angles each hand makes with 12 o'clock and report the smallest of the three pairwise angles. | Easy3 | MathGeometry+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Joint AttackConvert a continued fraction given as coefficients into a single reduced fraction, with numerator and denominator under 10^18. | Easy3 | MathImplementation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Pongdang Pongdang 2Decide whether Hwisu raises an arm on turn T of a circular drinking game where the number of arms per turn cycles up and down between 1 and 2N. | Easy3 | MathImplementation+1 | No attempts yet | 1s | 256 MB | Judgeable |
| Pongdang Pongdang 1Given N players and a turn T, find how many arms must be raised on turn T as the count cycles 1,2,...,2N,2N-1,...,1 repeatedly. | Easy3 | MathImplementation+1 | No attempts yet | 1s | 256 MB | Judgeable |
| CheckerboardGiven row heights and column widths that partition a grid into a v by h block matrix, color each block so side-adjacent blocks differ, starting Black at the top left. | Easy3 | ImplementationSimulation+1 | No attempts yet | 1s | 512 MB | Judgeable |
| NBA DraftClassify each player into one of four draft categories by comparing five integer statistics against expected ranges and their midpoints. | Easy3 | ImplementationMath+2 | No attempts yet | 2s | 512 MB | Judgeable |
| Cat FoodGiven a binary picture rotated 90 degrees counterclockwise, check whether it equals the students' picture under the reverse rotation. | Easy3 | ImplementationMatrix+2 | No attempts yet | 1s | 1024 MB | Judgeable |
| Strange Cipher CodeSplit a string into case-insensitive runs of equal letters, map each run to 1 if its length is at least K and 0 otherwise, and drop later runs whose letter already appeared. | Easy3 | StringImplementation+2 | No attempts yet | 1s | 1024 MB | Judgeable |
| Black and WhiteGiven an n by n grid of B and W cells, check that every row and column is balanced and has no three cells of the same color in a row. | Easy3 | ArrayImplementation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Basketball One-on-OneGiven a string recording who scored and how many points each time, determine which player won the basketball game under the eleven-point and win-by-two rules. | Easy3 | ImplementationSimulation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Soft PasswordsGiven a stored password S and an entered password P, decide whether P is accepted: equal to S, a digit-prepend/append of S, or the case-reversed form of S. | Easy3 | StringImplementation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| ZOAC 2A disk holds the 26 uppercase letters in a circle, and an arrow starts at 'A'. Find the minimum total rotations needed to print a given string in order. | Easy3 | ImplementationGreedy+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Square Eye TestIn a grid containing exactly one colored square border with a one-cell gap at the middle of a side, report which side has the gap. | Easy3 | ImplementationArray+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Queue 2Implement a queue supporting push, pop, size, empty, front, and back, and run N commands, printing output for the query commands. | Easy3 | QueueImplementation+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Boxing Day Football AnalysisGiven the order of N goals scored by two teams, report the final score, the number of tied scores reached during the match, and the longest run of successive goals that flipped a deficit into a lead. | Easy3 | SimulationImplementation+2 | No attempts yet | 1s | 512 MB | Judgeable |