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 results2,993 problems
| Title | Level | Topics | Solved | Time limit | Memory limit | Judge |
|---|---|---|---|---|---|---|
| Print Stars - 5Print a centered pyramid of stars with N lines, where line i has 2i-1 stars padded with spaces. | Easy1 | ImplementationSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| Star Printing - 13Given N, print a pyramid of stars that grows one star per line up to N then shrinks back down, using 2N-1 lines total. | Easy1 | ImplementationSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| Oven ClockGiven a start time and a number of minutes to cook, compute and print the finishing time on a 24-hour clock. | Easy1 | MathSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| Speed LimitGiven segments of constant speed with cumulative elapsed times, compute the total distance for each data set until n equals -1. | Easy1 | ImplementationMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Spinner Lock SimulationGiven the starting digits of a spinner lock and a sequence of button labels, add each label's digits to the wheels modulo 10 and print the final readout. | Easy1 | SimulationImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Sarah's ToysFor each night, subtract the toys left around the house from the total, then report how many pairs and whether one group of 3 is formed. | Easy1 | MathImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Pair SumThis is a straightforward simulation task where numbers in each test case are used to enumerate pairs. For each input n, all pairs of distinct natural numbers with sum n are printed in lexicographic order. Because n is at most 12, iterating all possible a and b values directly works. Implemented with simple loops, this problem is a typical warm-up exercise. | Easy1 | SimulationBrute force+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Match ResultsRead N rounds of scores for A and B, and report how many rounds each player won. | Easy1 | ImplementationSimulation | No attempts yet | 1s | 256 MB | Judgeable |
| TrianglesFor each size n read from input until 0, print a right triangle of stars with n rows, row i having i stars. | Easy1 | ImplementationSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| WężykPrint the numbers 1 to n squared in n rows that alternate between left-to-right and right-to-left order. | Easy1 | SimulationMatrix | No attempts yet | 1s | 128 MB | Judgeable |
| StrollGiven a walk of N, S, E and W steps on a grid, compute the Manhattan distance from the endpoint back to the start. | Easy1 | SimulationMath | No attempts yet | 2s | 128 MB | Judgeable |
| Erasing a File for GoodDecide if the second bit string is the first with every bit flipped N times, so it must equal the first for even N and its complement for odd N. | Easy1 | SimulationString | No attempts yet | 1s | 128 MB | Judgeable |
| PSU CampusesStarting and ending at Hatyai, sum the pairwise table distances along each given campus visit order. | Easy1 | Simulation | No attempts yet | 1s | 128 MB | Judgeable |
| Dice DuelBoth players start with 100 points, and in each round the player with the lower die loses points equal to the opponent's roll. | Easy1 | Simulation | No attempts yet | 1s | 256 MB | Judgeable |
| Heracles and the HydraStarting from h heads, each c adds one head and each b removes one, and you report the count left after all actions. | Easy1 | Simulation | No attempts yet | 1s | 256 MB | Judgeable |
| Reverse RotReverse each message, then shift every character forward by N places in the 28-symbol alphabet. | Easy1 | StringSimulation | No attempts yet | 1s | 256 MB | Judgeable |
| ServerCount how many jobs from the front finish in request order before their total duration exceeds T. | Easy1 | Prefix sumSimulation | No attempts yet | 1s | 256 MB | Judgeable |
| Vertical ReadingRead five given words column by column from top to bottom, skipping missing letters in shorter words, and print the letters in that order. | Easy1 | SimulationArray+1 | No attempts yet | 1s | 256 MB | Judgeable |
| Card GameCompare the ten cards of A and B round by round and print A or B for the side with more round wins, or D on a tie. | Easy1 | ArraySimulation | No attempts yet | 1s | 256 MB | Judgeable |
| Reversing Card SegmentsReverse ten given segments of a 20-card row that starts in order and print the final arrangement. | Easy1 | ArraySimulation | No attempts yet | 1s | 256 MB | Judgeable |
| Insert BallsFill N baskets by writing ball number k into baskets i through j for each operation, then print all baskets. | Easy1 | ArraySimulation | No attempts yet | 1s | 256 MB | Judgeable |
| Swap BallsSwap the balls in the given basket pairs M times and print the final ball in each of the N baskets. | Easy1 | SimulationArray | No attempts yet | 1s | 256 MB | Judgeable |
| Logical Functions: AND and ORCheck each submitted weight and bias by testing all four binary inputs and report whether the neuron matches the requested AND or OR gate. | Easy1 | SimulationImplementation | No attempts yet | 2s | 256 MB | Judgeable |
| PersistenceCount how many times multiplying the decimal digits together reduces the given number to a single digit. | Easy1 | SimulationImplementation | No attempts yet | 1s | 256 MB | Judgeable |
| Is Dinic quartic?Print a fixed 4-vertex, 5-edge flow network with the exact edges and capacities given in the statement. | Easy1 | GraphImplementation+1 | No attempts yet | 2s | 512 MB | Judgeable |
| Java2016Given a target constant c, print 20 fixed macro definitions and then build one expression by appending a macro for each set bit of c. | Easy1 | ImplementationSimulation+2 | No attempts yet | 2s | 512 MB | Judgeable |
| The Y Bus Goes VroomSimulate the passenger count as a bus travels N stops with given boarding and alighting numbers, then print the driver's fixed name. | Easy1 | SimulationImplementation+1 | No attempts yet | 2s | 256 MB | Judgeable |
| FizzBuzzPrint the numbers 1 through N, writing Fizz for multiples of X, Buzz for multiples of Y, and FizzBuzz for multiples of both. | Easy1 | ImplementationMath+2 | No attempts yet | 1s | 512 MB | Judgeable |
| Linear Algebra and GroupOutput the sum of the digits appearing in the cover illustration of a specific linear algebra textbook. | Easy1 | ImplementationMath+2 | No attempts yet | 1s | 256 MB | Judgeable |
| RectangleImplement a Rectangle class with width and height, range-checked setters, and methods for area, perimeter, and square detection. | Easy1 | ImplementationMath+2 | No attempts yet | 1s | 512 MB | Judgeable |
| BingoPrint the fixed 5x5 bingo board showing which cells are colored, with # for colored and . for empty. | Easy1 | ImplementationSimulation | No attempts yet | 0.999s | 511 MB | Judgeable |
| What an Easy ProblemImplement a function that returns the move losing to Kyojun each round, given the move he announces before playing. | Easy1 | ImplementationSimulation | No attempts yet | 1s | 512 MB | Judgeable |
| A+B (MC)Build a Minecraft redstone circuit that reads two integers from a command interpreter and outputs their sum. | Easy1 | SimulationImplementation+1 | No attempts yet | 1s | 512 MB | Judgeable |
| White SquaresGiven an 8x8 board marked with pieces and empty cells, count how many pieces sit on the white squares of the standard alternating coloring. | Easy2 | ArrayImplementation+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Mobile Phone BillGiven up to 20 call durations, compute total cost under two per-block billing plans and print the cheaper one with its cost. | Easy2 | SimulationImplementation+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Easy Sequence SumGiven a sequence where each integer k repeats k times, compute the sum of terms between positions A and B. | Easy2 | MathSimulation+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Actual Disk SpaceGiven N file sizes and a cluster size, compute total disk space used by rounding each file up to the nearest cluster multiple and summing. | Easy2 | MathImplementation+1 | No attempts yet | 2s | 128 MB | Judgeable |
| PetSimulate feeding and exercising a pet's weight across scenarios and report whether it ends happy, sad, or dead based on simple weight thresholds. | Easy2 | SimulationImplementation | No attempts yet | 1s | 128 MB | Judgeable |
| Floor DecorationCount the number of wooden planks by counting maximal runs of consecutive '-' in each row and '|' in each column of a grid. | Easy2 | MatrixImplementation+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Song ScoresGiven cumulative durations of N song scores, answer Q queries asking which score is being sung at a given time using prefix sums and search. | Easy2 | Prefix sumBinary search+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Organizing BooksSimulate packing books into boxes in order, sealing a box once the next book no longer fits, and sum the leftover capacity of every box. | Easy2 | SimulationImplementation+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Internet Cafe Seat RequestsGiven a sequence of seat requests for 100 computers, count how many requests are rejected because the requested seat is already taken. | Easy2 | SimulationArray+1 | No attempts yet | 2s | 128 MB | Judgeable |
| BallTrack which of three cups covers a ball as cups swap positions M times, then output the cup number holding it. | Easy2 | SimulationImplementation | No attempts yet | 2s | 128 MB | Judgeable |
| Sequence TransformationRepeatedly replace a sequence with its adjacent differences K times and print the resulting shorter sequence. | Easy2 | ArraySimulation+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Find Places to Lie DownCount maximal horizontal and vertical runs of at least two consecutive empty cells in an N x N grid. | Easy2 | MatrixSimulation | No attempts yet | 2s | 128 MB | Judgeable |
| Chicken CouponsGiven n chicken coupons and a stamp-to-coupon exchange rate k, compute the maximum chickens obtainable by repeatedly redeeming stamps for new coupons. | Easy2 | MathSimulation+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Growth PointsSimulate a tree that multiplies its leaves by a yearly factor then subtracts pruned branches, and report the final leaf count. | Easy2 | SimulationMath | No attempts yet | 1s | 128 MB | Judgeable |
| Packing Books into BoxesGiven book weights in order and a per-box weight limit, compute the minimum number of boxes needed by greedily filling each box in sequence. | Easy2 | GreedyArray+1 | No attempts yet | 2s | 128 MB | Judgeable |
| Right-Aligned StarsPrint N lines of right-aligned stars, where line i has i stars padded with leading spaces to align the right edge. | Easy2 | ImplementationSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| Star Printing - 6Print a centered triangle of stars whose width decreases by 2 each line from 2N-1 down to 1. | Easy2 | ImplementationSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| Star Printing - 8Print a diamond-like star pattern of width 2N where side star counts rise from 1 to N then fall back to 1, with spaces filling the middle. | Easy2 | ImplementationSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| Intelligent TrainSimulate passengers getting off and on at four stations and output the maximum train occupancy at any point. | Easy2 | SimulationImplementation | No attempts yet | 1s | 128 MB | Judgeable |
| Intelligent Train 2Given boarding and alighting counts at 10 stations, simulate the running passenger total and print its maximum value. | Easy2 | SimulationArray | No attempts yet | 1s | 128 MB | Judgeable |
| Dice GameFor each player's three dice rolls, compute a prize using given rules and print the maximum prize among all players. | Easy2 | SimulationImplementation | No attempts yet | 1s | 128 MB | Judgeable |
| Score CalculationCompute a total score from a 0/1 sequence where consecutive correct answers score an increasing running count. | Easy2 | ArraySimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Card GameSimulate 10 rounds of card comparisons between two players, scoring points, and determine the overall winner using the most recent non-tied round as a tiebreaker. | Easy2 | SimulationArray | No attempts yet | 1s | 128 MB | Judgeable |
| Binary AdditionAdd two binary strings up to length 80 for multiple test cases and print the sum without leading zeros. | Easy2 | StringSimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Maximum Value of a Fraction TableGiven a 2x2 grid of positive integers, find how many 90-degree clockwise rotations (0-3) maximize A/C+B/D, choosing the smallest such count on ties. | Easy2 | Brute forceImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Climbing SnailCompute the number of days for a snail climbing A meters by day and sliding B meters by night to reach a pole of height V. | Easy2 | MathSimulation | No attempts yet | 0.25s | 128 MB | Judgeable |
| Sorting Wooden PiecesSimulate repeated bubble-sort passes on five labeled pieces, printing the arrangement after every swap until sorted. | Easy2 | SimulationSorting+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Answer Pattern GuessingGiven an answer string, count matches against three fixed repeating guess patterns and report the highest score and who achieved it. | Easy2 | SimulationString+1 | No attempts yet | 1s | 128 MB | Judgeable |
| ATM TransactionsProcess ATM withdrawal or deposit lines, updating balance but rejecting withdrawals that push it below -200, until a sentinel line ends input. | Easy2 | SimulationImplementation | No attempts yet | 1s | 128 MB | Judgeable |
| Changyeong Village Cup ShuffleTrack the position of a ball among three cups after a sequence of swap operations described by characters A, B, C. | Easy2 | SimulationString | No attempts yet | 1s | 128 MB | Judgeable |
| ScannerExpand an R by C character grid by repeating each character ZR times vertically and ZC times horizontally, then print the result. | Easy2 | SimulationImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Scaled ChessboardPrint a checkerboard of R by C cells where each cell is scaled to an A by B block of X or dot characters. | Easy2 | SimulationImplementation | No attempts yet | 1s | 128 MB | Judgeable |
| BUHAGiven up to 100 square bomb-range constraints on an A by B grid, count how many cells satisfy all the inside/outside conditions. | Easy2 | ArraySimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Vigenère Cipher EncryptionEncrypt repeated plaintext lines with a repeating key using a shifted Vigenère cipher until a line with 0 appears. | Easy2 | StringSimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| ElectrificationGiven switch-to-lamp toggle mappings and a sequence of switch flips, compute and print the final on/off state of each lamp using parity counting. | Easy2 | SimulationBit manipulation | No attempts yet | 2s | 256 MB | Judgeable |
| Cutting a BlockGiven a box and n, print the coordinates of n equal slabs formed by evenly spaced cuts along the x-axis, each rounded to 8 decimals. | Easy2 | MathSimulation+1 | No attempts yet | 2s | 64 MB | Judgeable |
| MinesweeperGiven a grid of mines and empty cells, replace each empty cell with the count of mines in its eight neighbors. | Easy2 | SimulationImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| LogoTrack a turtle's position and heading through forward, backward, left, and right commands, then report the rounded distance from the start. | Easy2 | SimulationGeometry+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Prerequisites?Given Freddie's chosen courses and category minimums, check whether each category has at least the required number of his courses. | Easy2 | ImplementationHash map+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Combination LockGiven the dial position and three combination numbers, sum the degrees turned clockwise and counter-clockwise to open the lock. | Easy2 | SimulationMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Rock Paper Scissors?Count each player's round wins in rock paper scissors across n rounds and print the player with more wins, or TIE. | Easy2 | SimulationImplementation | No attempts yet | 1s | 128 MB | Judgeable |
| Bubble Gum, Bubble Gum, in the Dish, How Many Pieces Do You Wish?Given a list of names arranged in a circle, a starting person, and a count n, find who is at position n in the count. | Easy2 | ArraySimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Number Card GameFor each starting number S, repeatedly replace it with the product of its digits until a single digit appears, printing every value in order. | Easy2 | SimulationImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Rock, Paper, ScissorsGiven two equal-length strings of R, P, S moves, count the rounds each player wins. | Easy2 | StringImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| QuicksumCompute a weighted checksum for each input line: sum each character's 1-based position times its letter value, where spaces count as 0, until a line with only #. | Easy2 | StringImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| St. IvesFor each floating-point n until a terminating 0, print 1 + n + n^2 + n^3 + n^4 rounded to two decimals. | Easy2 | MathImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Fifty Coats of GrayGiven room dimensions, opening sizes, and the area one can covers, compute the total paintable area for n apartments and round up to whole cans. | Easy2 | MathImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Roaming RomansConvert each English-mile distance into Roman miles and paces using a fixed ratio, rounding the pace count to the nearest integer. | Easy2 | MathImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| The Twin ParadoxGiven Earth time and spaceship time, compute the ship's average speed as a fraction of light speed and print it to three decimals. | Easy2 | MathImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Parlay WageringSimulate a sequence of parlay wagers: apply each money-line multiplier with truncation, skip ties, and format the final payout with commas. | Easy2 | SimulationImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| A Contesting DecisionGiven each team's submissions and solve times for four problems, compute solved count and penalty, then print the winner. | Easy2 | ImplementationSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| General Chemistry LabGiven a sequence of temperatures ending with 999, print each temperature's difference from the previous one, rounded to two decimals. | Easy2 | ImplementationMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Number Guessing GameFor each n0, report whether 3*n0 is odd or even and print n4, the quotient of (n2*3)/9. | Easy2 | ImplementationMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| SavingsFor each test case, print how many years of multiplying the balance by (1 + B/100) are needed until it first exceeds M. | Easy2 | SimulationMath+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Jean and Joe's ClothesRead clothing sizes and count how many items go to Joe, Jean, Jane, James, or no one, per visit until N equals 0. | Easy2 | ImplementationSimulation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| DVDsApply a series of clamped sale and restock transactions to each DVD title's stock and report the final count. | Easy2 | ImplementationSimulation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Oil ExplorationFor each column of a grid, scan downward and sum drilling costs (H costs 3, S costs 1) until the first oil cell, or print N if none exists. | Easy2 | ArraySimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Isn't It Funny How a Bear Likes Honey?Given Pooh's weight and the radii of several spherical helium balloons, decide whether their combined lift strictly exceeds his weight. | Easy2 | MathImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| Aerospace & Mechanical EngineeringGiven each stage's mass, burn time, and thrust, simulate the rocket's vertical motion and report its height when the last stage falls off. | Easy2 | SimulationImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| String TransformationsApply each letter-to-two-letters rule to the first occurrence of its letter in every word, updating the word after each rule. | Easy2 | StringImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Counting Swann's CoinsPrint numbers 1 through N, replacing multiples of 3 with Dead, of 5 with Man, and of 15 with DeadMan, breaking the line after each word. | Easy2 | ImplementationMath+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Fill the Rowboats!Print the numbers 1 through N, inserting the word Go! after every sixth number and after the last one. | Easy2 | ImplementationSimulation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Secret LocationEach of six lines encodes one number by its character count; print the first three as Latitude and the last three as Longitude in the given format. | Easy2 | StringImplementation+2 | No attempts yet | 1s | 128 MB | Judgeable |
| J-BoxPrint an N by N grid whose border cells are '#' and interior cells are 'J', with a blank line between test cases. | Easy2 | ImplementationSimulation | No attempts yet | 1s | 128 MB | Judgeable |
| Mars MathEvaluate a chain of at most three Mars operations (@, %, #) on a starting number and print the result to two decimals. | Easy2 | SimulationImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Letter TrianglesFor each data set, print a triangle of N lines where line i repeats the ith letter in sequence, starting from a given letter and wrapping Z to A. | Easy2 | ImplementationString+1 | No attempts yet | 1s | 128 MB | Judgeable |
| Football TeamRead names one per line and swap every i with e and every I with E in each name. | Easy2 | StringImplementation+1 | No attempts yet | 1s | 128 MB | Judgeable |