Math and counting

Number theory, combinatorics, and geometry

Under construction

Still being built. Things may change

Total results13,153 problems

Chess Puzzle
Easy2
Brute force, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Long Python
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Commemorative Dice
Easy2
Brute force, Math+1
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Cutting Corners
Easy2
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bicycle
Easy2
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Right-Coupled Numbers
Easy2
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Big Money
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
A Colorful Problem
Easy2
Implementation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
VCR++ Codes
Easy2
Bit manipulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Operation: Save the Raffle Prize! (Easy)
Easy2
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Tax
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Buffon's Needle
Easy2
Geometry, Implementation+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Grading
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Minigolf
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Archaeologist Yerin
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Methodic Multiplication
Easy2
String, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
New Financial Year
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Rating Problems
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Curve Speed
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Some Sum
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cakes
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Comfy Deviations
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mars Message
Easy2
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Contest Struggles
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Count of Numbers 2
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Air Conditioner
Easy2
Implementation, Simulation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Laptop Sticker
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
K 2K Game
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Secret Instructions
Easy2
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Crazy Fencing
Easy2
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bank Transfer
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Chessboard
Easy2
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Monsters
Easy2
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Palindromes
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Basalt Breakdown
Easy2
Math, Geometry+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Exam
Easy2
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Pie Chart
Easy2
Math, Implementation+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Tariffs
Easy2
Implementation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Quality-Adjusted Life-Year
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Splitting the Bill
Easy2
Implementation, Math+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Binary Division
Easy2
Math, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Matrix Inverse
Easy2
Math, Matrix+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Does Not Compute
Easy2
Implementation, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Coding Biorhythm
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hongik Absolute Grading
Easy2
Implementation, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
JavaScript
Easy2
String, Implementation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Street Coding Fighter
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Arm Coordination
Easy2
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Let's Make a SASA Model
Easy2
Math, Implementation+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Bishop Tour
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
What Makes 2021 Special?
Easy2
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Food Delivery
Easy2
Implementation, Matrix+1
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Poster mailing
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tab Hopping
Easy2
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Algorithm Class - Algorithm Runtime 4
Easy2
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Algorithm Runtime 5
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Algorithm Runtime 6
Easy2
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
ПЪТУВАНЕ
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Algorithm Class - Asymptotic Notation 1
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Making Change
Easy2
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Meeting of Friends
Easy2
Math, Intervals+1
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
Clock
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Zayo Bayo
Easy2
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Algorithm Class - Asymptotic Notation 4
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Asymptotic Notation 5
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Asymptotic Notation 6
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Class - Fibonacci Number 1
Easy2
Implementation, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Fergusonball Ratings
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Scaling Recipe
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Double Password
Easy2
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Average Character
Easy2
String, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pooling PCR Tests
Easy2
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Transporting Spaghetti
Easy2
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Betting
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Beehives
Easy2
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Amazing Human Cannonball
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Number Fun
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Climbing Worm
Easy2
Math, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Two Rabbits
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Counting Antibodies
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Calendar of Alpha Centauri
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Binary Game 2
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
두~~부 두부 두부
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cake slices
Easy2
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gahee and Ignoring Defense Rate
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
A Very Simple Problem
Easy2
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Puang and Jongyun
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Shuttle Bus
Easy2
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Making Hamburgers
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Attendance Event
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Computation - Task 1
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Minigames with Ims
Easy2
Hash map, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Decimal XOR
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cat's Age
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
SGA President
Easy2
Hash map, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mission Donation
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Fastest Function
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Big Yield
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Vertical Calendar
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Buying in Bulk
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Chess PuzzleGiven a knight's square on an 8x8 board, place a rook and a bishop so each attacks the knight, they do not attack each other, and the knight attacks neither.	Easy2	Brute forceImplementation+2	No attempts yet	2s	512 MB	Judgeable
Long PythonGiven that a Python holds n whole Parrots or m whole Monkeys, find the minimum and maximum number of whole Parrots that fit into one Monkey.	Easy2	MathImplementation	No attempts yet	2s	512 MB	Judgeable
Commemorative DiceGiven two six-sided dice whose faces sum to 21, count the pairs where the first player's roll beats the second's and print the winning probability as a reduced fraction.	Easy2	Brute forceMath+1	No attempts yet	0.5s	512 MB	Judgeable
Cutting CornersGiven a stained w by h corner, compute how much longer the rectangular cut is than the diagonal cut.	Easy2	MathGeometry+2	No attempts yet	1s	512 MB	Judgeable
BicycleFor each of two bike rental plans, compute the monthly cost over 21 working days given a daily riding time T and per-minute overage rates.	Easy2	MathImplementation+1	No attempts yet	2s	512 MB	Judgeable
Right-Coupled NumbersFor each x below 215, decide whether x has a factor pair a*b = x with a <= b and a/b >= 0.5, printing 1 or 0.	Easy2	Brute forceMath+1	No attempts yet	1s	1024 MB	Judgeable
Big MoneySum n decimal amounts given in euros with two cent digits each, and print the exact total in the same format.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
A Colorful ProblemFor each RGB color after the first 16, print it, the words "maps to", and the target color with the smallest Euclidean distance.	Easy2	ImplementationBrute force+2	No attempts yet	1s	512 MB	Judgeable
VCR++ CodesRead scheduling lines and pack channel, month, day, year, start time, and length into the 32-bit VCR++ code, then print its decimal value.	Easy2	Bit manipulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
Operation: Save the Raffle Prize! (Easy)Given a prime m and three values Seed, X1, X2, find a and c such that X1 = (aSeed + c) mod m and X2 = (aX1 + c) mod m.	Easy2	Brute forceMath+1	No attempts yet	1s	512 MB	Judgeable
TaxGiven a prize amount N, compute what the student keeps when 22% is taxed outright, and when only 22% of the remaining 20% after an 80% expense deduction is taxed.	Easy2	MathImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Buffon's NeedleGiven N unit-length needle segments, count how many cross a vertical line x = k, then output 2 divided by that fraction.	Easy2	GeometryImplementation+1	No attempts yet	4s	1024 MB	Judgeable
GradingGiven counts of satisfied A, C, and E criteria, print the grade from E up to A using the half-threshold rules for D and B.	Easy2	ImplementationMath+1	No attempts yet	1s	1024 MB	Judgeable
MinigolfGiven strokes per hole, with odd holes par 2 and even holes par 3 and any hole capped at 7 strokes, print the total score relative to par.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Archaeologist YerinFor each test case with a and b, compute the return value of the given triple nested loop, which equals (a+b)^2 * (a+b-1) / 2.	Easy2	MathImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Methodic MultiplicationRead two Peano-encoded natural numbers and print their product, also in Peano form.	Easy2	StringMath+2	No attempts yet	2s	1024 MB	Judgeable
New Financial YearGiven the new price P and the percent change C for each flavor, recover the original price O using the formula C = 100(P-O)/O.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
Rating ProblemsGiven some judges' ratings, find the minimum and maximum possible average once the remaining judges submit ratings between -3 and 3.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
Curve SpeedRead radius and superelevation pairs until EOF and print the maximum curve speed from the given formula, rounded to the nearest integer.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Some SumGiven N consecutive positive integers picked from 1 to 100, decide whether their sum is always even, always odd, or can be either.	Easy2	MathImplementation+2	No attempts yet	1s	1024 MB	Judgeable
CakesGiven how much of each of N ingredients one cake needs and how much you have, find the largest number of cakes you can bake.	Easy2	ImplementationMath+1	No attempts yet	1s	512 MB	Judgeable
Comfy DeviationsRead 10 temperatures, compute the sample standard deviation with n-1, and print COMFY if it is at most 1.0, otherwise NOT COMFY.	Easy2	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Mars MessageRead N angles, map each to a hex digit by which 22.5 degree sector it falls in, pair them into ASCII codes, and print the decoded text.	Easy2	ImplementationString+2	No attempts yet	1s	1024 MB	Judgeable
Contest StrugglesGiven the average difficulty of all n problems and the average of the k solved ones, find the average of the remaining problems or report it impossible.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Count of Numbers 2Multiply three positive integers and count how many times each digit 0 through 9 appears in the decimal representation of the product.	Easy2	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
Air ConditionerGiven the current room temperature, a target temperature, and one of four AC modes, output the temperature after one hour of operation.	Easy2	ImplementationSimulation+2	No attempts yet	2s	1024 MB	Judgeable
Laptop StickerDecide whether a sticker fits on a laptop lid with one centimeter of margin on every side, without rotating it.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
K 2K GamePrint how many integers from 1 to N have a units digit different from both the units digits of K and 2K, then list those integers.	Easy2	ImplementationMath+1	No attempts yet	1s	256 MB	Judgeable
Secret InstructionsDecode a list of five-digit instructions into left or right turns with step counts, carrying the previous direction when the first two digits sum to zero.	Easy2	ImplementationSimulation+2	No attempts yet	1s	1024 MB	Judgeable
Crazy FencingGiven the left and right heights and the width of each of N trapezoidal boards, output the total area of the fence.	Easy2	MathGeometry+2	No attempts yet	1s	1024 MB	Judgeable
Bank TransferGiven the transfer amount k, compute the commission of 25 tugriks plus 1 percent of k, clamped between 100 and 2000.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
ChessboardGiven an m by n chessboard and the color of one cell, decide whether black, white, or neither appears more often.	Easy2	MathImplementation+1	No attempts yet	2s	512 MB	Judgeable
MonstersEach monster with k fingers can form 2^k distinct sums by lifting any subset of powers of two; output the sum of 2^ki mod 1e9+7 over all monsters.	Easy2	MathCombinatorics+2	No attempts yet	1s	512 MB	Judgeable
PalindromesRead n integers and print the sum of those that read the same forwards and backwards.	Easy2	ImplementationMath+1	No attempts yet	1s	512 MB	Judgeable
Basalt BreakdownGiven the area of a regular hexagon, compute its perimeter, allowing a small floating-point error.	Easy2	MathGeometry+1	No attempts yet	1s	1024 MB	Judgeable
ExamGiven the exam start and end times and the minutes Igor needs, decide whether he finishes on time, up to an hour late, or fails.	Easy2	ImplementationMath	No attempts yet	2s	256 MB	Judgeable
Pie ChartGiven n numbers and a radius r, split the circle's area into sectors proportional to each number and print every sector's area.	Easy2	MathImplementation+1	No attempts yet	2s	256 MB	Judgeable
TariffsFor each of n tariffs, compute the monthly cost from the fee plus rounded call charges, and print the index of the cheapest one.	Easy2	ImplementationBrute force+2	No attempts yet	2s	256 MB	Judgeable
Quality-Adjusted Life-YearGiven N periods, each with a quality-of-life value and a duration in years, multiply and sum to get total QALY.	Easy2	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Splitting the BillEach of N attendees owes M/N yen; anyone with less pays everything they have. Sum the minimum of each attendee's money and the share.	Easy2	ImplementationMath+2	No attempts yet	8s	512 MB	Judgeable
Binary DivisionGiven a binary string M and an integer K, decide whether M is divisible by 2^K.	Easy2	MathString+1	No attempts yet	1s	1024 MB	Judgeable
Matrix InverseFor each 2x2 integer matrix, print its inverse over two lines with a case number, guaranteed to have integer entries.	Easy2	MathMatrix+1	No attempts yet	2s	1024 MB	Judgeable
Does Not ComputeRead arithmetic statements of the form A op B = C, check whether each result is correct, and report OKAY or DOES NOT COMPUTE per case.	Easy2	ImplementationMath+1	No attempts yet	2s	1024 MB	Judgeable
Coding BiorhythmFor each of N dates, compute a biorhythm value from the squared digit differences of the birth date and that date, then print the earliest date with the maximum value.	Easy2	ImplementationMath+1	No attempts yet	1s	512 MB	Judgeable
Hongik Absolute GradingGiven N distinct scores, a percentage X, and a cutoff Y, count how many students get an A under relative grading (top X%) and under absolute grading (score at least Y).	Easy2	ImplementationSorting+1	No attempts yet	1s	1024 MB	Judgeable
JavaScriptRead two short strings and print the JavaScript result of x - y, which is NaN if either string is not a valid number, otherwise their numeric difference.	Easy2	StringImplementation+2	No attempts yet	2s	1024 MB	Judgeable
Street Coding FighterGiven three technique difficulties, read each club's three members' usage counts, compute every club's total score, and print the maximum.	Easy2	ImplementationMath+1	No attempts yet	1s	512 MB	Judgeable
Arm CoordinationGiven a circle's integer center and radius, output four integer-coordinate corners of a smallest enclosing square.	Easy2	GeometryMath+1	No attempts yet	2s	1024 MB	Judgeable
Let's Make a SASA ModelGiven N S-shaped blocks and M A-shaped blocks, find how many models can be built when each model needs 2 S blocks and 2 A blocks.	Easy2	MathImplementation+2	No attempts yet	0.5s	512 MB	Judgeable
Bishop TourGiven a board and two squares, decide whether a bishop can travel from the start square to the end square using any number of diagonal moves.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
What Makes 2021 Special?Given N, find the smallest number greater than N that is the product of two consecutive primes, such as 43 × 47 = 2021.	Easy2	MathBrute force	No attempts yet	1s	1024 MB	Judgeable
Food DeliveryFind the weighted balance point row and column from a grid of food weights.	Easy2	ImplementationMatrix+1	No attempts yet	8s	1024 MB	Judgeable
Poster mailingGiven three paper basis weights, compute the total weight in grams of an envelope, two posters, and an info sheet from their dimensions.	Easy2	MathImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Tab HoppingGiven n tabs in a cycle and a sequence of tabs to visit, find the minimum total number of forward or backward steps starting from tab 1.	Easy2	SimulationImplementation+2	No attempts yet	2s	1024 MB	Judgeable
Algorithm Class - Algorithm Runtime 4For a given n, count how many times the inner statement of a nested double loop runs, and report the polynomial degree of that count.	Easy2	MathCombinatorics+2	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Algorithm Runtime 5Given n, count how many times the innermost statement of a triple nested loop runs, and print the polynomial degree of that count.	Easy2	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Algorithm Runtime 6Count how many times the triple nested loop runs for a given n, then report the polynomial degree of that count.	Easy2	MathCombinatorics+1	No attempts yet	1s	512 MB	Judgeable
ПЪТУВАНЕGiven a conference start time and fixed activity durations, compute the latest departure time so the group arrives at least 10 minutes early.	Easy2	MathImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Algorithm Class - Asymptotic Notation 1Given f(n) = a1n + a0 and constants c and n0, decide whether f(n) <= cn holds for every n >= n0.	Easy2	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Making ChangeFor each pair of cost and payment amounts, compute the change and break it into the fewest $50, $20, $10, $5, and $1 bills.	Easy2	GreedyMath+2	No attempts yet	1s	1024 MB	Judgeable
Meeting of FriendsGiven two available time intervals and one minute when the second friend is busy, count the minutes both are free at the same time.	Easy2	MathIntervals+1	No attempts yet	0.1s	1024 MB	Judgeable
ClockGiven a start time and an end time on a 24-hour clock, compute the elapsed minutes (less than a day) and the number of full 30-minute laps.	Easy2	MathImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Zayo BayoGiven x cabbages, a travel time of n days per trip, and a start date, find the date when the last cabbage reaches home.	Easy2	SimulationImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Algorithm Class - Asymptotic Notation 4Given a quadratic f(n) and constants c, n0, decide whether f(n) <= c*n^2 holds for every n >= n0.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Asymptotic Notation 5Given a quadratic f(n) and positive c, n0, decide whether c*n^2 <= f(n) holds for every n >= n0, printing 1 or 0.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Asymptotic Notation 6Given a quadratic f(n)=a2n^2+a1n+a0 and constants c1, c2, n0, decide whether c1n^2 <= f(n) <= c2n^2 holds for every n >= n0.	Easy2	MathImplementation+1	No attempts yet	1s	512 MB	Judgeable
Algorithm Class - Fibonacci Number 1Given n, count how many times the base case of naive recursive Fibonacci runs and how many times the DP loop body runs.	Easy2	ImplementationMath+2	No attempts yet	1s	512 MB	Judgeable
Fergusonball RatingsFor each player, compute 5 times points minus 3 times fouls, count how many exceed 40, and mark the team gold if all do.	Easy2	ImplementationMath+1	No attempts yet	1s	1024 MB	Judgeable
Scaling RecipeScale each ingredient amount from a recipe that makes x portions so it makes y portions instead.	Easy2	MathImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Double PasswordGiven two four-digit passwords, count how many four-digit sequences match at least one password in every digit position.	Easy2	MathCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Average CharacterGiven a printable ASCII string, output the character whose ASCII value is the floor of the average of all characters' ASCII values.	Easy2	StringMath+1	No attempts yet	1s	1024 MB	Judgeable
Pooling PCR TestsGiven the chance p that one person tests positive, find the pool size N (2 to 16) that minimizes expected PCR tests per person, or print 1.	Easy2	MathBrute force	No attempts yet	1s	1024 MB	Judgeable
Transporting SpaghettiFind the fewest full trucks from Milan so that Mestre keeps exactly D tons and the rest, shipped in full boats, is at least C tons for Venice.	Easy2	MathBrute force	No attempts yet	1s	1024 MB	Judgeable
BettingGiven the percentage a of switch points bet on option one, print the payout ratio x for each option, where the ratio is 1:x.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
BeehivesGiven hive coordinates and a distance d, count the hives within d of another hive (sour) and the hives with no such neighbor (sweet).	Easy2	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
The Amazing Human CannonballFor each test case, the task checks whether the cannonball's height where it crosses the wall is at least 1 m above the lower edge and at least 1 m below the upper edge.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Number FunGiven triples a, b, c, the task is to check whether c equals a+b, a-b, b-a, a*b, a/b, or b/a for one operation, printing Possible or Impossible.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Climbing WormGiven a climb a, a slide b, and a pole height h, the task is to count how many crawls the worm needs to reach the top.	Easy2	MathSimulation	No attempts yet	1s	1024 MB	Judgeable
Two RabbitsTwo rabbits hop toward each other by fixed distances each second; find the time they land on the same point, or -1 if they never do.	Easy2	MathImplementation	No attempts yet	1s	256 MB	Judgeable
Counting AntibodiesGiven the gene fragment counts for the kappa, lambda, and heavy chains, count how many distinct antibody molecules can be formed.	Easy2	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Calendar of Alpha CentauriGiven a calendar with m months of d days each and a w-day week labeled a to the w-th letter, find the weekday letter for day i of month j in year k.	Easy2	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Binary Game 2Given n, print the binary digits of every number from 0 to n in order, concatenated into one digit sequence.	Easy2	ImplementationMath	No attempts yet	1s	512 MB	Judgeable
두~~부 두부 두부Given N players in a circle, caller M, and called mo count K, output the number of the player whose mo count is K, who takes the next turn.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Cake slicesGiven up to 10 cake slices, where slice i is 1/c_i of a cake, count the subsets whose total size is between 99/100 and 101/100 of a cake.	Easy2	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
Gahee and Ignoring Defense RateGiven a monster's defense rate a and the user's ignore defense b (in percent), print 1 if the remaining defense rate is under 100, otherwise print 0.	Easy2	MathImplementation	No attempts yet	1s	512 MB	Judgeable
A Very Simple ProblemFor each query with positive integers a and b, decide whether positive integers x and y exist with gcd(x, y) = a and x + y = b.	Easy2	MathNumber theory	No attempts yet	1s	1024 MB	Judgeable
Puang and JongyunGiven two two-digit numbers, compute their product with the Vedic method, printing the intermediate values a, b, c, d, q, r and the product's two halves.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Shuttle BusGiven the one-way trip time x and the bus's arrival time y at Engineering Building 2, find the minimum minutes to wait for the bus at the station.	Easy2	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Making HamburgersGiven A buns and B patties, find the maximum number of hamburgers, where each hamburger uses two buns and one patty.	Easy2	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Attendance EventGiven stamps collected and an item price, the task is to find the minimum payment using at most one coupon whose tier the stamp count unlocks.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Computation - Task 1Given real numbers a and b, write an instruction program that prints -2a-2b using input, addition, negation, and shift operations.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Minigames with ImsCount the distinct names, then divide by the other players each game needs: 1 for Yut Nori, 2 for Find the Same Picture, 3 for One Card.	Easy2	Hash mapMath	No attempts yet	1s	512 MB	Judgeable
Decimal XORGiven two integers up to 999,999, compute their digit-wise DEXOR, where each digit pair gives 0 if both digits are at most 2 or both are at least 7, otherwise 9.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Cat's AgeGiven a cat's age in years and months, convert it to human age in years and months using the 15, 9, and 4 rule.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
SGA PresidentGiven n first names, count ordered pairs of names with different spellings that start with the same letter.	Easy2	Hash mapString+1	No attempts yet	1s	1024 MB	Judgeable
Mission DonationFor each game, add up each mission's payout (K per kill, minus D per death, plus A per assist), skipping negative missions, and print the total.	Easy2	ImplementationMath	No attempts yet	1s	512 MB	Judgeable
Fastest FunctionGiven foo's percentage of total running time before and after an optimisation, output the factor by which foo itself got faster.	Easy2	MathImplementation	No attempts yet	1s	2048 MB	Judgeable
Big YieldGiven the total milk L and the pouring time T, find the difference between the two buckets' amounts, where the longer pour equals the larger bucket.	Easy2	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Vertical CalendarGiven year N and the weekday of January 1, count the calendar columns that have 5 cells across the months of that year.	Easy2	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Buying in BulkGiven item count c and unit price p for each customer, compute the total cost when every item after the first gets a $2 discount.	Easy2	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable