Problems

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Total results29,471 problems

Pairs
Easy3
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Number of Divisors
Easy3
Brute force, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sum
Easy3
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Basketball
Easy3
Simulation, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Catalan Master's Segment Drawing Game
Easy3
Game theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Chino's Latte Art (Easy)
Easy3
Implementation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Age Difference
Easy3
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Smallest Calculated Value
Easy3
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
String Conversion and Queries 2
Easy3
String, Implementation+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Fraction Finding 2
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Director Shom 2
Easy3
Brute force, Implementation
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Factorial 4
Easy3
Math, Implementation
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
What Should We Name the Contest
Easy3
String, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Math Quiz
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Block Adventure
Easy3
Greedy, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Sum of Two Numbers
Easy3
Math, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
2023, the Year of the Black Rabbit
Easy3
String, Greedy
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Making a Mandal-art
Easy3
Implementation, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Balmer's Peak Theory
Easy3
Sliding window, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Alphabet Blocks
Easy3
Stack, Simulation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
RGB트리
Easy3
Tree, Dynamic programming
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Sum of Primes
Easy3
Dynamic programming, Number theory
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Jeju Chocolate Guard
Easy3
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bell (Bell)
Easy3
Binary search, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
7Krokods
Easy3
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Moo Operations
Easy3
String, Brute force
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Champernowne Count
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
I Could Have Won
Easy3
Brute force, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Restaurant Opening
Easy3
Matrix, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Streets Ahead
Easy3
Hash map, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sun and Moon
Easy3
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Walking Boy
Easy3
Greedy, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Determining Nucleotide Assortments
Easy3
Prefix sum, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Brain fold (Easy)
Easy3
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Tokenizer
Easy3
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Adjusting passwords
Easy3
String, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Boredom buster (Easy)
Easy3
Dynamic programming, Recursion
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Knee problems (Easy)
Easy3
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Against a rock play Spock
Easy3
Greedy, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Buying Stamps
Easy3
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mushroom Farm
Easy3
BFS, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Overexcited Fan
Easy3
Simulation, Math
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Counting Subsequences
Easy3
Prefix sum, Hash map+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hungry Cow
Easy3
Greedy, Simulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
You You See What?
Easy3
String, Hash map+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
PSET
Easy3
Brute force, Implementation
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Gahee and the Crossing That Never Opens
Easy3
Intervals, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Interview
Easy3
Array, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
UDPC Party
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Coin Puzzle
Easy3
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hyundai Mobis Hiring Project
Easy3
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bodybuilding
Easy3
Array, Prefix sum
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
N-Concatenation
Easy3
Math, Implementation
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
△
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
I LOVE JavaScript
Easy3
Stack, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Lazy Evaluation
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Joker
Easy3
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Plain Constructive Problem
Easy3
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pushing Down Spires
Easy3
Greedy, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Do the Times Overlap?
Easy3
Prefix sum, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Copying Coins
Easy3
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Minheejin
Easy3
String, String matching+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Uni's Letter Writing
Easy3
Prefix sum, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Eungae (EASY)
Easy3
Simulation, Array
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Last Problem
Easy3
Sorting, Greedy
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Sum of Arithmetic Sequences
Easy3
Math, Implementation
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Selection Sort Movement Distance
Easy3
Array, Simulation
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
2023 Ajou University Programming Contest
Easy3
String, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Space-A
Easy3
Math, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Won, Tak!
Easy3
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Huh? Can't hear you
Easy3
Hash map, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Four Square
Easy3
Implementation, Brute force
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
Space Alignment
Easy3
Brute force, Implementation+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Classical A+B Problem
Easy3
Math, Implementation+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Two Triangles
Easy3
Brute force, Implementation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Laboratory Report
Easy3
Implementation, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Math Teacher's Worry (Easy)
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Eve, Psyche and the Wife of the Blue MEX
Easy3
Combinatorics, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Nadori Merge
Easy3
Union-find, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Chocolate Storage Box
Easy3
DFS, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Destiny
Easy3
Array, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Number of Digits
Easy3
Math, Implementation
No attempts yet
Time limit
0.25s
Memory limit
512 MB
Judgeable
Trianglane
Easy3
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sharing Snacks with Cats
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Unstable Sequence
Easy3
Array, Greedy
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Wooksin-ness of a graph
Easy3
Graph, Union-find+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Image Filter
Easy3
Implementation, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cat Cafe
Easy3
Sorting, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Stop Cheating!
Easy3
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Guess the Birthday
Easy3
Brute force, Bit manipulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bucket Game
Easy3
Graph, Topological sort+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Addition
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
XOR Card Game
Easy3
Dynamic programming, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Matrix Operations (Compute the Matrix)
Easy3
Array, Implementation
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Bowling Ball Finder
Easy3
Hash map, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Choosing Malatang Ingredients
Easy3
Brute force, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Who Wins?
Easy3
Prefix sum, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
I want to do conventional deadlifts
Easy3
Dynamic programming, Matrix
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Array Rotation
Easy3
Simulation, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Toe Jumps
Easy3
Implementation, Matrix
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
PairsSplit four given integers into two pairs and print the largest possible sum of the two pair products.	Easy3	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
Number of DivisorsGiven n, find the number from 1 to n that has the most divisors, and print that number with its divisor count.	Easy3	Brute forceMath	No attempts yet	1s	1024 MB	Judgeable
SumCount the ways to write a given integer n (1 to 1000) as a sum of odd summands, where summands in a different order count as the same.	Easy3	Dynamic programming	No attempts yet	1s	1024 MB	Judgeable
BasketballSimulate m substitutions between the odd-position and even-position teams, then list the players on the court in alphabetical order.	Easy3	SimulationSorting	No attempts yet	1s	1024 MB	Judgeable
Catalan Master's Segment Drawing GameGiven N points on a circle, decide the winner of the non-crossing segment drawing game for both coin outcomes, P=0 and P=1.	Easy3	Game theoryMath	No attempts yet	1s	1024 MB	Judgeable
Chino's Latte Art (Easy)Given a grid of cream cells, decide whether they form exactly one N x N square with an M x M corner removed, with no holes or extra lumps.	Easy3	ImplementationBrute force+1	No attempts yet	1s	1024 MB	Judgeable
Age DifferenceGiven N resident ages, print for each resident the largest age difference between that resident and any other resident.	Easy3	ArrayImplementation	No attempts yet	2s	1024 MB	Judgeable
Smallest Calculated ValueGiven three integers, the task is to find the smallest non-negative value from placing one of four operators between each pair, evaluated left to right, with exact division only.	Easy3	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
String Conversion and Queries 2Apply character replacement queries to a string, and after each type 2 query print the longest run of one repeated character.	Easy3	StringImplementation+1	No attempts yet	3s	512 MB	Judgeable
Fraction Finding 2Given X up to 10^18, find the X-th fraction when the infinite table is read in zigzag diagonal order.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Director Shom 2Given N, find the Nth smallest positive integer that contains at least three consecutive 6s.	Easy3	Brute forceImplementation	No attempts yet	0.5s	1024 MB	Judgeable
Factorial 4Given N from 0 to 100,000, print N! exactly. The result has up to about 456,000 digits, so the program needs big-number multiplication.	Easy3	MathImplementation	No attempts yet	5s	1024 MB	Judgeable
What Should We Name the ContestGiven string S, decide whether some subsequence of length M ends with A, A, then a consonant, and print one such subsequence if it exists.	Easy3	StringGreedy	No attempts yet	1s	1024 MB	Judgeable
Math QuizGiven N integers A_k, find real p and q so that the sum of omega^A_k equals p*omega + q, where omega is a root of x^2 + x + 1 = 0.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Block AdventureGiven column heights, a bag of blocks, and a tolerance k, decide whether the character can walk from column 1 to column n by adding or removing blocks.	Easy3	GreedyImplementation	No attempts yet	1s	256 MB	Judgeable
Sum of Two NumbersGiven n, the task is to split n into two non-negative parts x and y whose digit sums differ by at most 1.	Easy3	MathGreedy	No attempts yet	1s	1024 MB	Judgeable
2023, the Year of the Black RabbitCount how many serial numbers from 1 to N have 2023 as a subsequence of their digits.	Easy3	StringGreedy	No attempts yet	2s	512 MB	Judgeable
Making a Mandal-artGiven a 9x9 mandal-art grid, print each intermediate goal with its 8 detailed goals, sorted lexicographically at both levels.	Easy3	ImplementationSorting+1	No attempts yet	1s	1024 MB	Judgeable
Balmer's Peak TheoryCount the hours when the alcohol consumed in the last L hours keeps blood alcohol concentration between 0.129 and 0.138 until the test starts.	Easy3	Sliding windowArray	No attempts yet	1s	1024 MB	Judgeable
Alphabet BlocksSimulate button presses that add letters to either end of a string and remove the most recent addition, then print the final string or 0 if empty.	Easy3	StackSimulation	No attempts yet	1s	512 MB	Judgeable
RGB트리Color each bulb of a tree red, green, or blue so adjacent bulbs differ, maximizing the total beauty, and print the best sum and coloring.	Easy3	TreeDynamic programming	No attempts yet	1.5s	1024 MB	Judgeable
Sum of PrimesCount the ways to write each query n as an unordered sum of primes, modulo 1,000,000,007, with up to 10,000 queries and n up to 100,000.	Easy3	Dynamic programmingNumber theory	No attempts yet	3s	128 MB	Judgeable
Jeju Chocolate GuardAfter each eating event, print the remaining chocolate total in a base set by the previous total's ones digit, then list the kinds with nonzero counts sorted by count.	Easy3	ImplementationSimulation+1	No attempts yet	1s	512 MB	Judgeable
Bell (Bell)Given sorted bell positions and house positions, print for each house K minus the distance to the nearest bell, clamped at 0.	Easy3	Binary searchArray	No attempts yet	2s	1024 MB	Judgeable
7KrokodsAssign each of m wildcard cards to the letters d, k, o, or r to maximize the sum of squared letter counts plus 7 points per krokod word formable.	Easy3	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
Moo OperationsGiven strings of M and O, find the fewest end-flips and end-deletions that turn each one into MOO, or -1 if impossible.	Easy3	StringBrute force	No attempts yet	2s	1024 MB	Judgeable
Champernowne CountCount how many of the first n Champernowne words, the concatenations of 1 through m, are divisible by k.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
I Could Have WonGiven a string of point winners, find every k where Alice wins more games than Bob under the first-to-k rule.	Easy3	Brute forceSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Restaurant OpeningPlace one restaurant on a grid of resident counts so the total Manhattan distance from all residents to it is minimized, and print that minimum.	Easy3	MatrixBrute force	No attempts yet	1s	1024 MB	Judgeable
Streets AheadGiven street names in road order, answer each query with the number of intersections from the start street to the end street, inclusive.	Easy3	Hash mapImplementation	No attempts yet	2s	1024 MB	Judgeable
Sun and MoonGiven when the sun and moon were last in position and each one's cycle length, find the number of years until both line up again.	Easy3	MathBrute force	No attempts yet	1s	1024 MB	Judgeable
Walking BoyGiven the minutes when messages were sent, decide whether two non-overlapping 120-minute walks fit in the gaps, with walks allowed to touch messages.	Easy3	GreedyImplementation	No attempts yet	2s	1024 MB	Judgeable
Determining Nucleotide AssortmentsGiven a DNA string and many range queries, output the four nucleotides ordered by count in each range, with ties broken by ATGC order.	Easy3	Prefix sumSorting+1	No attempts yet	1s	1024 MB	Judgeable
Brain fold (Easy)Given a sequence of folds and one cut line on the folded paper, find how many pieces the sheet has after unfolding, modulo 1e9+7.	Easy3	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
TokenizerSplit a shell command line at the delimiters <, >, &&, \|\|, (, ), and spaces, then print the non-space tokens separated by single spaces.	Easy3	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Adjusting passwordsGiven the correct password P and the mistyped prompt text Q, find the fewest keystrokes (letters, backspace, enter) that log in.	Easy3	StringGreedy	No attempts yet	1s	1024 MB	Judgeable
Boredom buster (Easy)Given n, split each integer by fixed rules and find the maximum total of y*z over all splits until n ones remain.	Easy3	Dynamic programmingRecursion	No attempts yet	1s	1024 MB	Judgeable
Knee problems (Easy)Given n steps, count the ways to climb using steps of 1 or 2 and descend using steps of 1 to 4, modulo 10^9 + 9.	Easy3	Dynamic programming	No attempts yet	1s	1024 MB	Judgeable
Against a rock play SpockGiven the opponent's gestures in advance, output a gesture that beats each one while never repeating your previous gesture.	Easy3	GreedyImplementation	No attempts yet	1s	1024 MB	Judgeable
Buying StampsCount the ways to buy stamps worth exactly K won from N kinds of 1-won and M kinds of 2-won stamps, modulo a prime P.	Easy3	Dynamic programming	No attempts yet	1s	1024 MB	Judgeable
Mushroom FarmGiven a grid of growable and blocked cells, find the fewest spores needed so each spore covers up to K connected growable cells, then report the leftover spores.	Easy3	BFSGraph+1	No attempts yet	2s	512 MB	Judgeable
Overexcited FanGiven Peppurr's starting offset and move string, find the earliest minute you can meet Peppurr at an intersection, or report IMPOSSIBLE.	Easy3	SimulationMath	No attempts yet	20s	1024 MB	Judgeable
Counting SubsequencesCount the contiguous subarrays of a sequence whose elements sum to exactly 47.	Easy3	Prefix sumHash map+1	No attempts yet	2s	1024 MB	Judgeable
Hungry CowGiven haybale deliveries on specific days, count how many haybales Bessie eats in the first T days, eating one per day when stock is on hand.	Easy3	GreedySimulation	No attempts yet	2s	1024 MB	Judgeable
You You See What?Remove the repeated machine hops from a UUCP bang path so the mail reaches the same recipient through a shorter route.	Easy3	StringHash map+1	No attempts yet	10s	1024 MB	Judgeable
PSETCount the triples of PSET cards that form a PSET, where each card may be flipped and the top and bottom SET cards each form a SET.	Easy3	Brute forceImplementation	No attempts yet	5s	1024 MB	Judgeable
Gahee and the Crossing That Never OpensGiven arrival times of upbound and downbound trains, find how many seconds the crossing barrier stays up. Each train blocks the crossing for 40 seconds.	Easy3	IntervalsSorting+1	No attempts yet	1s	1024 MB	Judgeable
InterviewFor each query X, count the contiguous groups of students among the first X that contain no student in Eunho's grade.	Easy3	ArrayPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
UDPC PartyGiven a vote string where U and C can be swapped and D and P can be swapped, find which mascots can strictly win the vote.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Coin PuzzleGiven two coin grids of up to 10 by 10, find the fewest coins to move so the first arrangement becomes the second by translation only.	Easy3	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
Hyundai Mobis Hiring ProjectPick K of N lectures to maximize the total of whichever two of the three ability scores (a, b, c) come out highest.	Easy3	GreedySorting	No attempts yet	1s	1024 MB	Judgeable
BodybuildingGiven daily weight gains and minimum weight bounds, find the most routine runs (each losing X kg) that keep his weight above every day's bound.	Easy3	ArrayPrefix sum	No attempts yet	1s	512 MB	Judgeable
N-ConcatenationGiven N and K, find the remainder when the concatenation 123...N of the integers 1 through N is divided by K.	Easy3	MathImplementation	No attempts yet	1.5s	1024 MB	Judgeable
△Given N, build a tree on N vertices that minimizes the sum of distances over all vertex pairs, then print that minimum and the edges.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
I LOVE JavaScriptGiven a nested ASON string, compute its total size in bytes, where each integer costs 8, each string costs its length plus 12, and each object adds 8.	Easy3	StackImplementation	No attempts yet	2s	1024 MB	Judgeable
Lazy EvaluationApply add and multiply updates to a set of 1 to 1234567890123, delete the smallest n elements, and print the minimum after each query.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
JokerGiven four cards and a joker, find the replacement card that makes the highest poker hand without duplicating a card already held.	Easy3	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
Plain Constructive ProblemGiven N and M intervals, build a sequence of length N with the largest K such that every interval contains all values 1 to K.	Easy3	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Pushing Down SpiresCount the pushes needed to topple all N spires, where a falling spire knocks the next one only if it is taller than that spire.	Easy3	GreedyImplementation	No attempts yet	1s	512 MB	Judgeable
Do the Times Overlap?Given N closed time intervals [S, E] of seat use, count how many intervals contain each queried time t.	Easy3	Prefix sumSorting+1	No attempts yet	1s	512 MB	Judgeable
Copying CoinsGiven an N by N grid with one coin at (x, y), find the minimum number of directional machine runs needed to fill every cell with coins.	Easy3	ImplementationSimulation	No attempts yet	1s	1024 MB	Judgeable
MinheejinGiven N names, count the pairs of people where a non-empty suffix of one name matches a prefix of the other.	Easy3	StringString matching+1	No attempts yet	1s	512 MB	Judgeable
Uni's Letter WritingGiven each friend's enlistment and discharge months, find the earliest month when the most friends are in the military.	Easy3	Prefix sumArray	No attempts yet	1s	1024 MB	Judgeable
Eungae (EASY)Members stand in a circle, and a member greets next round only if exactly one neighbor greeted this round. Count the greeters after K rounds.	Easy3	SimulationArray	No attempts yet	2s	1024 MB	Judgeable
Last ProblemGiven N distinct difficulties, find the lowest integer in their range that maximizes the minimum distance to all of them, or -1 if none exists.	Easy3	SortingGreedy	No attempts yet	0.5s	1024 MB	Judgeable
Sum of Arithmetic SequencesGiven sequence A, decide whether it splits into two arithmetic sequences B and C with A_i = B_i + C_i, and print B and C if it does.	Easy3	MathImplementation	No attempts yet	3s	1024 MB	Judgeable
Selection Sort Movement DistanceGiven a permutation, run selection sort and report the total distance each value moves across all swaps.	Easy3	ArraySimulation	No attempts yet	5s	1024 MB	Judgeable
2023 Ajou University Programming ContestRestore each word Seonwoo altered using a lookup table, or report failure when half or more of its letters were replaced.	Easy3	StringHash map+1	No attempts yet	1s	1024 MB	Judgeable
Space-AGiven a fixed string of R, U, X moves and a list of target points, count how many points the robot can reach by picking a subsequence of moves.	Easy3	MathString	No attempts yet	1s	1024 MB	Judgeable
Won, Tak!Given N numbers on a circle, find the fewest cuts between adjacent entries so that every resulting arc reads in ascending order.	Easy3	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Huh? Can't hear youCount the unordered pairs of given points whose connecting line has slope K.	Easy3	Hash mapMath	No attempts yet	2s	1024 MB	Judgeable
Four SquareGiven four rectangular panes, decide whether they can be rotated and placed without overlap to tile a square.	Easy3	ImplementationBrute force	No attempts yet	4s	2048 MB	Judgeable
Space AlignmentGiven a file whose indentation mixes tabs and spaces, find the smallest tab width that makes every line's indentation a consistent multiple of one unit, or report -1.	Easy3	Brute forceImplementation+1	No attempts yet	1s	2048 MB	Judgeable
Classical A+B ProblemGiven a number n written as a sum of two repdigits, the task is to output any such pair of repdigits a and b.	Easy3	MathImplementation+1	No attempts yet	4s	1024 MB	Judgeable
Two TrianglesGiven two triangular arrays of 0s and 1s with size N, rotate or reflect A to find the fewest positions where it differs from B.	Easy3	Brute forceImplementation+1	No attempts yet	2s	1024 MB	Judgeable
Laboratory ReportGiven reference tables and patient results, print a fixed-width lab report that flags each result against its table's ranges.	Easy3	ImplementationString+1	No attempts yet	2s	1024 MB	Judgeable
Math Teacher's Worry (Easy)For a given n, factor n x^2 + (n+1)x - (n+2) over the integers and print the coefficients, or print -1 if no factorization exists.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Eve, Psyche and the Wife of the Blue MEXGiven N integers, compute the sum of mex({A_i, A_j}) over all pairs i<j of the array.	Easy3	CombinatoricsMath	No attempts yet	1s	1024 MB	Judgeable
Nadori MergeGiven Nadori sizes and merge queries, print the sum of pairwise size products inside the merged group after each union.	Easy3	Union-findMath	No attempts yet	1s	1024 MB	Judgeable
Chocolate Storage BoxGiven a 3x3 chocolate box with a blocked center, check whether the sizes of its connected chocolate groups match the numbers on the screen.	Easy3	DFSMatrix+1	No attempts yet	1s	1024 MB	Judgeable
DestinyCount the left-right sock pairs whose colors differ, given X left socks, X right socks, and K possible colors.	Easy3	ArrayMath	No attempts yet	1s	1024 MB	Judgeable
Number of DigitsGiven integers a and b, count how many decimal digits a raised to the power b has.	Easy3	MathImplementation	No attempts yet	0.25s	512 MB	Judgeable
TrianglaneGiven a two-row strip of unit triangles, each marked black or white, find the perimeter of the black region in meters.	Easy3	ImplementationSimulation	No attempts yet	1s	1024 MB	Judgeable
Sharing Snacks with CatsGiven each cat's share of every treat as a fraction, find the gap between the largest and smallest totals as an irreducible fraction.	Easy3	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Unstable SequencePick the most numbers in their original order so that every two adjacent picked numbers have an odd sum, meaning their parities alternate.	Easy3	ArrayGreedy	No attempts yet	1.5s	1024 MB	Judgeable
Wooksin-ness of a graphGiven undirected graphs, find the fewest edges to add so the graph contains a cycle, or print -1 if that is impossible.	Easy3	GraphUnion-find+1	No attempts yet	1s	1024 MB	Judgeable
Image FilterFor each cell of a heightmap, pick the prediction filter and residual with the smallest absolute error, breaking ties by the lexicographically smallest pair.	Easy3	ImplementationGreedy	No attempts yet	1s	1024 MB	Judgeable
Cat CafePair up cats so each pair's total weight is at most K, and find the maximum number of pairs that can be formed.	Easy3	SortingTwo pointers+1	No attempts yet	2s	1024 MB	Judgeable
Stop Cheating!Assign one of the fewest paper kinds to each cell of an N by M grid so that no two cells touching by side or corner share a kind.	Easy3	ImplementationMath	No attempts yet	2s	1024 MB	Judgeable
Guess the BirthdayGiven the digits in Chanwoo's ID, count the calendar dates in a leap year whose month and day share no digits with those ID digits.	Easy3	Brute forceBit manipulation	No attempts yet	2s	1024 MB	Judgeable
Bucket GameWater poured into bucket 1 splits equally among each bucket's outgoing hoses in a DAG. Find the largest amount any single bucket holds.	Easy3	GraphTopological sort+1	No attempts yet	2s	1024 MB	Judgeable
AdditionGiven a sequence, add 1 to three adjacent values per operation to make the odd-position and even-position sums equal, then find the minimum operations or -1.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
XOR Card GameSplit the deck into consecutive groups of 2 or 3 cards to maximize the total count of 1 bits in each group's XOR. A leftover single card gives 0.	Easy3	Dynamic programmingBit manipulation	No attempts yet	1s	1024 MB	Judgeable
Matrix Operations (Compute the Matrix)Given Q operations that add a value to a whole row or column of an N by M zero matrix, print the final matrix.	Easy3	ArrayImplementation	No attempts yet	3s	1024 MB	Judgeable
Bowling Ball FinderEach type 1 request puts a ball of a given weight into a locker, and each type 2 request asks which locker holds the ball of a given weight.	Easy3	Hash mapImplementation	No attempts yet	1s	1024 MB	Judgeable
Choosing Malatang IngredientsGiven an N by N compatibility matrix, find the largest sum of pairwise scores over exactly K chosen ingredients.	Easy3	Brute forceBit manipulation	No attempts yet	1s	1024 MB	Judgeable
Who Wins?Given two lists of coding skills, count how many cross-team matches HI wins, how many ARC wins, and how many end in a draw.	Easy3	Prefix sumSorting+1	No attempts yet	1s	1024 MB	Judgeable
I want to do conventional deadliftsFind the minimum sum of watchfulness values on a right-and-down path from the top-left to the bottom-right cell of a grid, then check whether it is at most H.	Easy3	Dynamic programmingMatrix	No attempts yet	1s	1024 MB	Judgeable
Array RotationGiven an N by N array and a list of row shifts and 90-degree turns, print the array after applying all operations in order.	Easy3	SimulationMatrix+1	No attempts yet	1s	1024 MB	Judgeable
Toe JumpsGiven a 2x2 grid of ice marks and a travel direction, the task is to identify which toe jump (Toe Loop, Flip, or Lutz) left the marks, or output ? if none match.	Easy3	ImplementationMatrix	No attempts yet	1s	1024 MB	Judgeable