Problems

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Total results29,471 problems

Letters
Easy3
Matrix, Simulation+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Eccentric Encryption
Easy3
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Period
Easy3
String, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
SORT
Easy3
String, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
FIBA
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Genius
Easy3
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
HŽ
Easy3
Intervals, Prefix sum
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stain
Easy3
Brute force, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hungry Ari Buys a Sandwich
Easy3
Bit manipulation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ari's Strange Judging
Easy3
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Clean Sequence (Easy)
Easy3
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Durumari Effect
Easy3
String, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Card Draw
Easy3
Implementation, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hate Stagnant Water
Easy3
Union-find, Graph
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ensemble Gomgom
Easy3
Probability, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Gahee and the Chaos Papulatus
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Gahui and File Explorer 2
Easy3
Hash map, String+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
solved.ac 2022 difficulty rating
Easy3
Implementation, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Multi-Item Preference Survey (Large)
Easy3
Hash map, Implementation
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Sums of Numbers 8
Easy3
Prefix sum, Hash map+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Buying Pants
Easy3
Math, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Planetary Alignment
Easy3
Math, Number theory
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Beat the Card Product
Easy3
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Count the Products of Card Numbers
Easy3
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Dividing the Digits of an Integer in Base k
Easy3
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Calculating grades
Easy3
Implementation, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cards in Place
Easy3
Greedy, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Parking Tower
Easy3
Sorting, Array+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Fast Number Search
Easy3
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Turn Integer A into K
Easy3
Greedy, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Counting integers with adjacent digits differing by at most 2
Easy3
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sports Day
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Linear Functions
Easy3
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Find DKSH
Easy3
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Eurokulen
Easy3
Array, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ad Astra
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ims, Master of Accessories
Easy3
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Master of Recursion
Easy3
Two pointers, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Depth of the Tree Node with Value k
Easy3
Tree, BFS
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Minimum cost to color a tree
Easy3
Dynamic programming, Tree
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Harvesting Apples at Tree Nodes Within Distance k
Easy3
Tree, BFS
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
OPK
Easy3
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Meeting place
Easy3
Brute force, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Delivery Box Painting
Easy3
Implementation, Matrix
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Found a Troll
Easy3
Array, Simulation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Quiet Sort
Easy3
Array, Sorting
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Work Hell for Puang (Large)
Easy3
Hash map, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Baduk Stone Game
Easy3
Math, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Puang Stuck in Shift Hell (Small)
Easy3
Hash map, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Type Casting in Java
Easy3
Tree, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Balanced Sotteok Skewer
Easy3
String, Prefix sum
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
String Tower
Easy3
String, Brute force
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Max Rise
Easy3
Array, Greedy
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bicycle Stunts
Easy3
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bead Bracelet String Length
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Computation - Task 3
Easy3
Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Simplified Calendar System
Easy3
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Letter Frequency
Easy3
Array, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pseudo Pseudo Random Numbers
Easy3
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
House Prices Going Up
Easy3
Array, Prefix sum
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Square Fishing Net
Easy3
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Aqualin
Easy3
BFS, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fiborooji Sequence
Easy3
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Caterpillar Walk
Easy3
Implementation, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Overall Ranking
Easy3
Hash map, Sorting
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Don't Complicate It!
Easy3
Stack, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
How Much Coffee is Left?
Easy3
Math, Geometry
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tower Climbing
Easy3
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ims Who Solved 2000 Problems
Easy3
Sliding window, Array
No attempts yet
Time limit
1s
Memory limit
1000 MB
Judgeable
Sum of Sums of Squared Binomial Coefficients
Easy3
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Tetrooj Box
Easy3
Array, Simulation
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Give-a-Gnocchi
Easy3
Number theory, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Historical TV Remote Control
Easy3
Brute force, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rounding Many Ways
Easy3
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Simple Darts
Easy3
Geometry, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Phoneme Palindromes
Easy3
Two pointers, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Loopy Word Search
Easy3
String matching, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Balanced Strings
Easy3
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Balance Scale
Easy3
Simulation, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bae Chanwoo likes arrays
Easy3
Array, Implementation
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Hash Hacking
Easy3
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
K.O. Kids
Easy3
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ace Arbiter
Easy3
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Waiting Line at the Cafeteria Entrance
Easy3
Queue, Simulation
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
Cafeteria Menu
Easy3
Queue, Simulation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
On the Planet Ivoril
Easy3
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Friendly Chongchong
Easy3
Hash map, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Expiration Date
Easy3
Implementation, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DPS
Easy3
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Complete Sequences
Easy3
Prefix sum, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sugar Delivery 2
Easy3
Math, Greedy
No attempts yet
Time limit
0.25s
Memory limit
1024 MB
Judgeable
Parentheses Tree
Easy3
String, Tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Longest Bar Magnet
Easy3
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Impromptu Trip (Easy)
Easy3
Graph, BFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Flappy Bird Scoring
Easy3
Array, Binary search
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Rock is rock too
Easy3
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Artificial Elements
Easy3
Number theory, Brute force
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Traverse the Whole Array
Easy3
Sorting, Binary search
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Playing 23
Easy3
Simulation, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Piecewise Linear Function
Easy3
Binary search, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
LettersGiven a grid of letters, apply a sequence of gravity directions (left, right, up, down) where letters slide until blocked, and print the final grid.	Easy3	MatrixSimulation+1	No attempts yet	2s	256 MB	Judgeable
Eccentric EncryptionGiven words S and T, find a key (a, b, c) that turns S into T under the Malnar cipher, or print -1 if none exists.	Easy3	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
PeriodGiven a repeating decimal 0.(digits) with the repeating block written three times, print its value as a fully reduced fraction, numerator then denominator.	Easy3	StringMath+1	No attempts yet	1s	1024 MB	Judgeable
SORTSort N words in Croatian dictionary order, where lj and nj each count as a single letter, and print them in sorted order.	Easy3	StringSorting	No attempts yet	1s	1024 MB	Judgeable
FIBAGiven round-robin game scores for N teams, find Croatia's points, the first-round winner, and the points the top K teams carry into round two.	Easy3	SimulationImplementation+1	No attempts yet	1s	1024 MB	Judgeable
The GeniusConverts audience and jury votes into points to rank the stars, then finds the jury member whose ranking is closest to the official show ranking.	Easy3	SortingImplementation	No attempts yet	1s	1024 MB	Judgeable
HŽCount the tickets whose route crosses a closed section, the fewest sections to reopen so no ticket needs a bus, and the longest run of stations with no closure.	Easy3	IntervalsPrefix sum	No attempts yet	1s	1024 MB	Judgeable
StainGiven a stain grid and a sticker grid, find the fewest stain cells left uncovered after rotating the sticker by 90-degree steps and shifting it anywhere.	Easy3	Brute forceMatrix+1	No attempts yet	1s	1024 MB	Judgeable
Hungry Ari Buys a SandwichGiven a sandwich price S and Kugi's money M, decide whether Ari can pay alone, needs Kugi's coins, or cannot pay even with Kugi's help.	Easy3	Bit manipulationMath	No attempts yet	1s	1024 MB	Judgeable
Ari's Strange JudgingGiven contest submission records, compute each participant's total points under the odd scoring rules and print the names from lowest to highest total.	Easy3	ImplementationSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Clean Sequence (Easy)Count the clean sequences of length 2N whose score is minimal, where N is at most 10.	Easy3	MathCombinatorics	No attempts yet	1s	1024 MB	Judgeable
Durumari EffectGiven two equal-length words, decide whether one is a rearrangement of the other, their first and last letters match, and they match after vowels are removed.	Easy3	StringSorting+1	No attempts yet	1s	1024 MB	Judgeable
Card DrawFor each day's four cards, check whether they form a consecutive triple, a triple of identical cards, or two identical pairs.	Easy3	ImplementationBrute force	No attempts yet	1s	1024 MB	Judgeable
Hate Stagnant WaterFor each visited tank K, decide whether its connected component has more clean (1) tanks than stagnant (0) tanks.	Easy3	Union-findGraph	No attempts yet	1s	1024 MB	Judgeable
Ensemble GomgomGiven N members who each pick one of K notes with equal probability, find the expected number of pairs that play the same note.	Easy3	ProbabilityMath	No attempts yet	1s	1024 MB	Judgeable
Gahee and the Chaos PapulatusGiven the clock time, zone percentages, and timed item and seal events, find the HP percentage Papulatus recovers when the pattern ends.	Easy3	SimulationImplementation+1	No attempts yet	1s	512 MB	Judgeable
Gahui and File Explorer 2Given users with their groups and files with three-digit permissions, owners, and owning groups, decide for each query whether the user can read, write, or execute the file.	Easy3	Hash mapString+1	No attempts yet	4s	512 MB	Judgeable
solved.ac 2022 difficulty ratingGiven N timestamped difficulty opinions (levels 1 to 30), compute a weighted average where newer opinions and the 0.9 per-rank decay raise weight, rounded to an integer.	Easy3	ImplementationMath	No attempts yet	2s	1024 MB	Judgeable
Multi-Item Preference Survey (Large)Given n students' subject, fruit, and color choices, each query asks how many students match its pattern, where '-' matches any value.	Easy3	Hash mapImplementation	No attempts yet	3s	512 MB	Judgeable
Sums of Numbers 8Count the index pairs (i, j) where the sum of A over the range [i, j] equals the sum of B over the same range.	Easy3	Prefix sumHash map+1	No attempts yet	1s	512 MB	Judgeable
Buying PantsCount the pants whose waist fits Siru's lower body circumference at a height equal to the pants' length, so the hem sits exactly at ground level.	Easy3	MathImplementation	No attempts yet	2s	1024 MB	Judgeable
Planetary AlignmentGiven the alignment periods T_1 to T_(N-2) for each triple of consecutive planets, find the period at which all N planets line up.	Easy3	MathNumber theory	No attempts yet	2s	1024 MB	Judgeable
Beat the Card ProductGiven n digits from 1 to 9, find a multiset of n digits from 1 to 9 with a larger product whose sorted concatenation is smallest, or print -1 if none exists.	Easy3	Brute forceMath+1	No attempts yet	1s	512 MB	Judgeable
Count the Products of Card NumbersGiven n, count the distinct products of n cards, each showing a digit from 1 to 9 with repetition allowed, where n is at most 7.	Easy3	MathBrute force	No attempts yet	1s	512 MB	Judgeable
Dividing the Digits of an Integer in Base kConvert n to base k, split its digits at each 0, and print the sum of the distinct nonempty pieces in base k.	Easy3	ImplementationMath	No attempts yet	1s	512 MB	Judgeable
Calculating gradesGiven N scores from 0 to 100, count how many students receive each Suneung grade from 1 to 9 using the cumulative-share cutoffs.	Easy3	ImplementationPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Cards in PlaceGiven a row of cards with values, find the fewest cards to remove so the remaining cards read 1, 2, 3, ... from left to right.	Easy3	GreedyArray+1	No attempts yet	1s	1024 MB	Judgeable
Parking TowerGiven a circle of N cars, find the fewest clockwise or counterclockwise rotations needed to remove all cars in increasing order of their numbers.	Easy3	SortingArray+1	No attempts yet	1.5s	1024 MB	Judgeable
Fast Number SearchFind the fewest moves on a 5 x 5 grid, avoiding -1 cells, from a given start cell to the cell containing 1, or report -1 if it is unreachable.	Easy3	BFSGraph+1	No attempts yet	1s	512 MB	Judgeable
Turn Integer A into KGiven A and K, find the minimum number of operations (add 1 or multiply by 2) needed to turn A into K.	Easy3	GreedyMath	No attempts yet	1s	512 MB	Judgeable
Counting integers with adjacent digits differing by at most 2Count n-digit positive integers with nonzero digits where adjacent digits differ by at most 2, modulo 987,654,321.	Easy3	Dynamic programming	No attempts yet	1s	512 MB	Judgeable
Sports DayGiven N teams of M members, a people still in the event, and K of them on Junhyeok's team, find the largest and smallest rank his team can have.	Easy3	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Linear FunctionsAssign each of the integers 1 to N to one of N linear functions so that the sum of the function values is maximized.	Easy3	GreedySorting	No attempts yet	1s	512 MB	Judgeable
Find DKSHCount the subsequences of a string of up to 100,000 uppercase letters that spell DKSH in order.	Easy3	Dynamic programmingString	No attempts yet	1s	512 MB	Judgeable
EurokulenGiven each farm's ranking of the other kulen, find the top three by points, then again after erasing the votes of farms that exchanged equal points with another farm.	Easy3	ArraySorting+1	No attempts yet	1s	1024 MB	Judgeable
Ad AstraCount workdays and weekend days among N dates on a custom calendar, plus the complete weekends between the first and last date.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Ims, Master of AccessoriesGiven current fatigue P and N accessories with fatigue costs A_i, find the most accessories Ims can craft while fatigue is under 200 before each craft.	Easy3	GreedySorting	No attempts yet	1s	1024 MB	Judgeable
Master of RecursionFor each string, report whether the recursive palindrome check returns 1 and how many times the recursion function is called.	Easy3	Two pointersString+1	No attempts yet	2s	1024 MB	Judgeable
Depth of the Tree Node with Value kGiven a rooted tree and a value k assigned to one vertex, print the depth of the vertex that holds value k.	Easy3	TreeBFS	No attempts yet	1s	512 MB	Judgeable
Minimum cost to color a treeGiven a tree rooted at 0 with white and black costs per vertex, find the minimum total cost so that every adjacent pair has different colors.	Easy3	Dynamic programmingTree	No attempts yet	1s	512 MB	Judgeable
Harvesting Apples at Tree Nodes Within Distance kCount the apples on vertices whose distance from root 0 is at most k in a given tree.	Easy3	TreeBFS	No attempts yet	1s	512 MB	Judgeable
OPKGiven each player's answers and the correct key, score each team by majority vote, find each team's weakest link, and pick the cyclic shift Y that maximizes the team's points.	Easy3	SimulationImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Meeting placeGiven N candidate names of length L, find an uppercase string of length L that differs from every candidate in at most one letter, or report CALL FRIEND.	Easy3	Brute forceString	No attempts yet	1s	1024 MB	Judgeable
Delivery Box PaintingGiven stacks of boxes on an N by M grid, count the boxes whose six faces all touch another box or the floor.	Easy3	ImplementationMatrix	No attempts yet	1s	1024 MB	Judgeable
Found a TrollGiven N streamers' viewer trends over M periods, decide whether at least half of the non-Ralpha streamers have an absolute-difference sum above 2000 against Ralpha.	Easy3	ArraySimulation+1	No attempts yet	1s	512 MB	Judgeable
Quiet SortGiven N distinct integers, find the minimum number of swaps needed to sort the array in ascending order.	Easy3	ArraySorting	No attempts yet	1s	512 MB	Judgeable
Work Hell for Puang (Large)Given a weekly duty roster with shifts of 4, 6, 4, and 10 hours, check whether everyone's total duty hours differ by at most 12.	Easy3	Hash mapImplementation	No attempts yet	1s	1024 MB	Judgeable
Baduk Stone GameGiven N stones, find the fewest stones to add so the first player wins a game where turn k must remove exactly k stones.	Easy3	MathSimulation	No attempts yet	1s	1024 MB	Judgeable
Puang Stuck in Shift Hell (Small)Given a multi-week four-shift schedule, check whether every worker's total shift hours differ from the others by at most 12 hours.	Easy3	Hash mapImplementation	No attempts yet	1s	1024 MB	Judgeable
Type Casting in JavaGiven a class inheritance tree, determine whether one of two named classes is an ancestor of the other so that casting between them is possible.	Easy3	TreeHash map+1	No attempts yet	2s	512 MB	Judgeable
Balanced Sotteok SkewerRemove characters only from the left end of an s/t string to get the longest remaining suffix with equal counts of s and t.	Easy3	StringPrefix sum	No attempts yet	1s	512 MB	Judgeable
String TowerGiven N strings of length M, decide whether each string can be placed on the previous one so that their overlapping parts match exactly.	Easy3	StringBrute force	No attempts yet	1s	512 MB	Judgeable
Max RiseGiven daily stock prices, find the maximum profit from one buy followed by one later sell, where selling on the same day gives zero.	Easy3	ArrayGreedy	No attempts yet	1s	512 MB	Judgeable
Bicycle StuntsFor each starting cell, count how many cells the rider steps on when riding forward over ramps on a road of N cells.	Easy3	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Bead Bracelet String LengthFind the minimum total length of a closed loop through all N distinct numbers, where each string costs the absolute difference of its two endpoints.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Computation - Task 3Read a real number a and output -1, 0, or 1 according to whether a is negative, zero, or positive, using the given instruction set.	Easy3	Implementation	No attempts yet	1s	1024 MB	Judgeable
Simplified Calendar SystemGiven a date in a 360-day calendar and its weekday, find the weekday of a later date.	Easy3	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Letter FrequencyGiven up to 20 lowercase words, find the most frequent letter at each position, listing all tied letters in alphabetical order.	Easy3	ArrayImplementation	No attempts yet	1s	1024 MB	Judgeable
Pseudo Pseudo Random NumbersCount the binary strings of length n that have no run of identical bits longer than k.	Easy3	Dynamic programmingCombinatorics	No attempts yet	1s	1024 MB	Judgeable
House Prices Going UpGiven house prices, process updates that raise one house's price and queries that return the total price of houses l through r.	Easy3	ArrayPrefix sum	No attempts yet	1s	1024 MB	Judgeable
Square Fishing NetGiven n fish points and a net side length s, find the most fish that one axis-aligned square of side s can cover, boundary included.	Easy3	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
AqualinGiven an n by n grid where each cell has an animal type and a color, compute the best same-type and same-color connected component scores.	Easy3	BFSMatrix+1	No attempts yet	1s	1024 MB	Judgeable
Fiborooji SequenceGiven two starting digits, generate each next term as the last digit of the sum of the previous two, and find the cycle length until the starting pair repeats.	Easy3	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Caterpillar WalkGiven non-overlapping buildings on the x-axis, find the total distance Lulu crawls along roofs and walls from x=0 to x=100.	Easy3	ImplementationArray	No attempts yet	1s	1024 MB	Judgeable
Overall RankingGiven team names listed by regional rank, output the universities sorted by the average of their team ranks, lowest average first.	Easy3	Hash mapSorting	No attempts yet	1s	1024 MB	Judgeable
Don't Complicate It!Given a string of parentheses and blanks, compute the total complexity where an innermost pair scores 1 and each pair one level out adds one more.	Easy3	StackImplementation	No attempts yet	1s	1024 MB	Judgeable
How Much Coffee is Left?Given a cone-frustum mug, the minutes already spent drinking, and the current coffee depth, find how many more minutes the rest of the coffee takes.	Easy3	MathGeometry	No attempts yet	1s	1024 MB	Judgeable
Tower ClimbingFind the minimum total jump time from the first to the last platform when each jump rises at most k layers and costs \|dx\| + dy^2.	Easy3	Dynamic programmingArray	No attempts yet	1s	1024 MB	Judgeable
Ims Who Solved 2000 ProblemsGiven daily solve counts and coins C, find the longest streak that at most 2 freezes can bridge over zero-solve days, plus the largest daily count.	Easy3	Sliding windowArray	No attempts yet	1s	1000 MB	Judgeable
Sum of Sums of Squared Binomial CoefficientsFor each n from 3 to M, add the squares of the binomial coefficients C(n,k) over k from 0 to n, and print the total modulo 10^9+7.	Easy3	MathCombinatorics	No attempts yet	1s	512 MB	Judgeable
Tetrooj BoxBlocks are dropped onto a base of width b, each landing on the base or the highest block below it. The task is to find the final tallest column height.	Easy3	ArraySimulation	No attempts yet	5s	1024 MB	Judgeable
Give-a-GnocchiGiven n and k, output the kth composite number that is not divisible by any prime up to n.	Easy3	Number theorySimulation	No attempts yet	1s	1024 MB	Judgeable
Historical TV Remote ControlGiven the broken digit buttons and a target channel, find the fewest channel up/down presses needed after typing a channel that can be entered with the working digits.	Easy3	Brute forceImplementation	No attempts yet	1s	1024 MB	Judgeable
Rounding Many WaysGiven N, list every X of the form 2^a * 5^b that divides N, since X must divide both 10^Z and N.	Easy3	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
Simple DartsGiven a circular board with w wedges and ring radii b, d, and s, sum the scores of each dart throw at (x, y) coordinates.	Easy3	GeometryImplementation	No attempts yet	1s	1024 MB	Judgeable
Phoneme PalindromesGiven pairs of letters that sound alike, check whether each string sounds the same read forward and backward.	Easy3	Two pointersString+1	No attempts yet	1s	1024 MB	Judgeable
Loopy Word SearchGiven letter grids that wrap at the edges, find each word's start cell and its direction (R, D, L, or U) in rows and columns.	Easy3	String matchingSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Balanced StringsCount the ways to fill each ? so that adjacent letters alternate between vowel and consonant, making the string balanced.	Easy3	ImplementationMath	No attempts yet	1s	1024 MB	Judgeable
Balance ScaleStones are placed on a balance by a fixed rule, and the task asks for the fewest weights from 1g to 100g needed to level the final imbalance.	Easy3	SimulationGreedy	No attempts yet	1s	1024 MB	Judgeable
Bae Chanwoo likes arraysGiven an N by M array, apply q queries that either set one cell or swap two rows, then print the final array.	Easy3	ArrayImplementation	No attempts yet	3s	512 MB	Judgeable
Hash HackingCount the length-N sequences over M symbols whose weighted sum mod M equals H, printed modulo 1000000007.	Easy3	MathNumber theory	No attempts yet	1s	1024 MB	Judgeable
K.O. KidsCount how many of k kids cross a 2 x n bridge when each follows the switching strategy and learns the real plates from earlier players.	Easy3	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Ace ArbiterCheck whether a log of ping pong scores with alternating serves can come from a real game, and find the first invalid entry.	Easy3	SimulationImplementation	No attempts yet	1s	1024 MB	Judgeable
Waiting Line at the Cafeteria EntranceSimulate a cafeteria entrance queue and report the peak line length with the back student's number, choosing the smallest number on ties.	Easy3	QueueSimulation	No attempts yet	0.1s	512 MB	Judgeable
Cafeteria MenuProcess arrival and meal records with a queue, then list the students who ate their favorite menu, ate the other menu, or never got to eat.	Easy3	QueueSimulation	No attempts yet	1s	512 MB	Judgeable
On the Planet IvorilEach word must become an alternating noun or an all-vowel verb; find the fewest character changes needed across all words.	Easy3	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Friendly ChongchongGiven N meeting records in order, count how many people are dancing the rainbow dance after the last record, starting from ChongChong alone.	Easy3	Hash mapSimulation	No attempts yet	1s	1024 MB	Judgeable
Expiration DateFor each food's expiration date, try every valid year/month/day reading and print invalid, safe, or unsafe by comparing with today's date.	Easy3	ImplementationBrute force	No attempts yet	1s	1024 MB	Judgeable
DPSCount the unordered groups of three people whose handle initials can be rearranged to spell the team name S.	Easy3	CombinatoricsMath+1	No attempts yet	1s	1024 MB	Judgeable
Complete SequencesCount the contiguous subsequences whose length and sum are both prime numbers.	Easy3	Prefix sumArray	No attempts yet	1s	1024 MB	Judgeable
Sugar Delivery 2Find the fewest 3-kg and 5-kg bags that add up to exactly N kilograms, or report -1 if no combination works.	Easy3	MathGreedy	No attempts yet	0.25s	1024 MB	Judgeable
Parentheses TreeGiven a balanced parentheses string that encodes a rooted ordered tree, sum the distances from the root to every leaf.	Easy3	StringTree+1	No attempts yet	1s	1024 MB	Judgeable
The Longest Bar MagnetFind the length of the longest substring that is a block of one letter followed by an equal-length block of the other letter, for a string of N and S.	Easy3	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Impromptu Trip (Easy)Given a directed graph of countries and flights, check whether every country can reach all the others.	Easy3	GraphBFS+1	No attempts yet	2s	1024 MB	Judgeable
Flappy Bird ScoringGiven each obstacle's gap A_i minus B_i, find for each bird size w how many obstacles it passes before meeting a gap smaller than w.	Easy3	ArrayBinary search	No attempts yet	1s	512 MB	Judgeable
Rock is rock tooCount the subsequences of a string of up to 1,000,000 uppercase letters that spell ROCK, modulo 1e9+7.	Easy3	Dynamic programmingString	No attempts yet	2s	512 MB	Judgeable
Artificial ElementsFor each atomic number up to 118, decide whether it can be written as the sum of two prime numbers.	Easy3	Number theoryBrute force	No attempts yet	1s	256 MB	Judgeable
Traverse the Whole ArrayGiven an array and queries counting elements at least k, greater than k, or within [i, j], print each count in order.	Easy3	SortingBinary search	No attempts yet	1s	512 MB	Judgeable
Playing 23Given two players' starting cards and the common cards so far, find the lowest next common card that lets Mary win the match in the next round.	Easy3	SimulationBrute force	No attempts yet	1s	1024 MB	Judgeable
Piecewise Linear FunctionGiven N points joined by line segments, report for each query x-coordinate k whether the piecewise linear function is increasing, decreasing, or flat there.	Easy3	Binary searchArray	No attempts yet	1s	1024 MB	Judgeable