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Total results2,362 problems

Grade Statistics
Easy2
Sorting, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Roll-call in Woop Woop High
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Breed Proximity
Easy2
Array, Hash map+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Contest Timing
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Math Practice
Easy2
Math, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
String Function Encoding
Easy2
String, Simulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Odd or Even
Easy2
String, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Barn Echoes
Easy2
String, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Papaya Jungle
Easy2
Simulation, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Scavenger Hunt
Easy2
Math, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hay Expenses
Easy2
Prefix sum, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Time Cards
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Statistics
Easy2
Array, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
TV Reports
Easy2
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
IBM Minus One
Easy2
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Color Me Less
Easy2
Implementation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Approximating e
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Getting Chorded
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Golf
Easy2
Implementation, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Perfection
Easy2
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ballot Evaluation
Easy2
Hash map, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Deli Deli
Easy2
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hard to Believe, but True!
Easy2
String, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Next in Line
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rotating Letters
Easy2
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Time on Task
Easy2
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Speed fines are not fine!
Easy2
Implementation, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Icon Scaling
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Big Bang Secrets
Easy2
Implementation, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sumac Sequences
Easy2
Simulation, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Unfriend
Easy2
Tree, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
English or French?
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
What is n, Daddy?
Easy2
Math, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Computer Purchase
Easy2
Sorting, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
ISBN 1-3-Sum
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Old Fishing Hole
Easy2
Brute force, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Good Times
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Body Mass Index
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Do the Shuffle
Easy2
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
It's Cold Here!
Easy2
Implementation, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Who is in the middle?
Easy2
Sorting, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
I Speak TXTMSG
Easy2
Hash map, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Deal or No Deal Calculator
Easy2
Implementation, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Anagram Checker
Easy2
Hash map, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Federal Voting Age
Easy2
Implementation, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Cell Sell
Easy2
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Snow Calls
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mouse Move
Easy2
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Squares
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Terms of Office
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Smile with Similes
Easy2
Implementation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Simple Encryption
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Trident
Easy2
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Constrained Permutations
Easy2
Brute force, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
0123456789
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
AmeriCanadian
Easy2
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fraction Action
Easy2
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dressing Up
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mod Inverse
Easy2
Number theory, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Calendar
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cross-Number Puzzle
Easy2
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shift Letters
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Anagrams
Easy2
String, Hash map+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
String
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Making test data 8
Easy2
Graph, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Nonogram
Easy2
Implementation, Array+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hidden Roman Numerals
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Numbers
Easy2
Math, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Building Blocks
Easy2
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cards
Easy2
Array, Hash map+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Worm Turns
Easy2
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Counting Sheep
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Entropy
Easy2
Hash map, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Expression
Easy2
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Right Triangle Check
Easy2
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Programming Contest Passwords
Easy2
Implementation, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gauss
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
StuPId
Easy2
Math, Implementation+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Stacked Bowls
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sexagenary Cycle (干支)
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cuboids
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jumbled Words
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Untied Airlines
Easy2
Implementation, Hash map
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
MP3 Songs
Easy2
Sorting, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bookings
Easy2
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
How Many Distinct Letters
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Exercise
Easy2
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
AAAAHH! Overbooked!
Easy2
Intervals, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Divisibility
Easy2
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Teleprime
Easy2
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Joke
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Huffman Tree
Easy2
Tree, String+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Concert
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Painting
Easy2
Array, Matrix+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ways to Make Rectangles
Easy2
Math, Brute force+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
A Cat on a Keyboard
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Polynomial
Easy2
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Kamil
Easy2
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Julka
Easy2
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ant Names
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Grade StatisticsFor each class, read the scores, then report the maximum, the minimum, and the largest gap between neighboring scores after sorting in descending order.	Easy2	SortingImplementation+1	No attempts yet	1s	128 MB	Judgeable
Roll-call in Woop Woop HighRead each class's answers and count pupils into four groups: correct first try, correct late, never correct, and absent.	Easy2	ImplementationString+1	No attempts yet	1s	128 MB	Judgeable
Breed ProximityGiven a line of N cows with breed ids, find the largest breed id whose two occurrences lie within K positions of each other, or -1 if none exist.	Easy2	ArrayHash map+1	No attempts yet	1s	128 MB	Judgeable
Contest TimingShe starts at 11:11 on 11/11. Given the day, hour, and minute she stops, print the minutes elapsed, or -1 if the stop is earlier.	Easy2	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
Math PracticeGiven A (0 to 45) and B (1 to 9), find the smallest E in 1 to 62 with E > A and 2^E starting with digit B, or 0 if none exists.	Easy2	MathBrute force+1	No attempts yet	1s	128 MB	Judgeable
String Function EncodingApply the given suffix-plus-string operation C times to each input string and print the results.	Easy2	StringSimulation	No attempts yet	1s	128 MB	Judgeable
Odd or EvenRead N large integers up to 10^60 and print odd or even for each, judging parity from the last digit.	Easy2	StringMath+2	No attempts yet	1s	128 MB	Judgeable
Barn EchoesGiven two lowercase strings, find the length of the longest string that is a prefix of one and a suffix of the other.	Easy2	StringBrute force+2	No attempts yet	1s	128 MB	Judgeable
Papaya JungleBessie moves greedily through a grid, always stepping to the adjacent square with the most uneaten papayas, and we sum the fruit she eats until she reaches the bottom-right corner.	Easy2	SimulationArray+2	No attempts yet	1s	128 MB	Judgeable
Scavenger HuntList every pair (x, y) where x divides P and y divides Q, sorted by x then y.	Easy2	MathBrute force+1	No attempts yet	1s	128 MB	Judgeable
Hay ExpensesGiven N daily hay counts and Q ranges, output the sum of counts over each range from S to E inclusive.	Easy2	Prefix sumArray	No attempts yet	1s	128 MB	Judgeable
Time CardsFor each cow, pair her START and STOP entries and print the total time she spent at the milking machine as hours and minutes.	Easy2	ImplementationSimulation+1	No attempts yet	1s	128 MB	Judgeable
StatisticsRead N integers, print their mean and median rounded to six decimal places.	Easy2	ArraySorting+2	No attempts yet	1s	128 MB	Judgeable
TV ReportsTrack daily Dollar prices against the previous day and the running all-time high, printing NTV drop headlines and BBTV record headlines in day order.	Easy2	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
IBM Minus OneFor each of n uppercase names, shift every letter to the next letter of the alphabet, wrapping Z to A, and print the result with numbered headers.	Easy2	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Color Me LessRead 16 target RGB colors, then map each following color to the nearest target color by Euclidean distance, breaking ties by earliest appearance.	Easy2	ImplementationBrute force+2	No attempts yet	1s	128 MB	Judgeable
Approximating ePrint approximations of e for n from 0 to 9, each rounded to 9 decimals with trailing zeros removed, under a fixed two-line header.	Easy2	ImplementationMath+1	No attempts yet	1s	128 MB	Judgeable
Getting ChordedGiven three note names, decide whether their semitone spacing forms a major or minor chord, then print the echo with the root-named chord or "unrecognized".	Easy2	ImplementationMath+1	No attempts yet	1s	128 MB	Judgeable
GolfFor each test case, turn a hole's par and John's stroke count into the standard golf score name, with hole-in-one taking priority.	Easy2	ImplementationMath+2	No attempts yet	1s	128 MB	Judgeable
PerfectionFor each number below 60000, sum its proper divisors and classify it as perfect, deficient, or abundant.	Easy2	MathNumber theory+1	No attempts yet	1s	128 MB	Judgeable
Ballot EvaluationSum the given parties' vote percentages and check the sum against an integer n using the guess's comparison operator.	Easy2	Hash mapImplementation+1	No attempts yet	1s	128 MB	Judgeable
Deli DeliFor each of N words, apply the first matching pluralization rule from a list of irregular forms and four suffix rules, then print the result.	Easy2	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Hard to Believe, but True!Read the numbers in each equation backwards, add them, and check whether the sum equals the backwards-read result.	Easy2	StringMath+1	No attempts yet	1s	128 MB	Judgeable
Next in LineGiven the ages of the youngest and middle of three children in an arithmetic sequence, print the oldest child's age.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Rotating LettersGiven a single uppercase word, decide whether every letter belongs to the set of seven letters that look the same after a 180-degree rotation.	Easy2	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Time on TaskGiven a time limit and chore durations, find the largest number of chores that can be completed in any order.	Easy2	GreedySorting	No attempts yet	1s	128 MB	Judgeable
Speed fines are not fine!Given a speed limit and a recorded speed, decide whether the car is speeding and print the matching fine from a three-tier table.	Easy2	ImplementationMath+2	No attempts yet	2s	512 MB	Judgeable
Icon ScalingRead scaling factor k and print the fixed 3x3 icon with every character expanded into a k-by-k block.	Easy2	StringImplementation	No attempts yet	2s	512 MB	Judgeable
Big Bang SecretsDecode an uppercase word by shifting each letter backward by S = 3P + K positions, where P is the letter's 1-based position.	Easy2	ImplementationString+1	No attempts yet	2s	512 MB	Judgeable
Sumac SequencesStarting from two integers, repeatedly replace the pair with (second, first minus second) until the difference turns negative and report how many terms appear.	Easy2	SimulationMath	No attempts yet	2s	512 MB	Judgeable
UnfriendCount the subsets of nodes in a rooted tree that can be removed, where removing a node forces removal of all its descendants.	Easy2	TreeBrute force+1	No attempts yet	2s	512 MB	Judgeable
English or French?Count the letters t and T against s and S across N lines and print English if t wins, otherwise French.	Easy2	StringImplementation	No attempts yet	2s	512 MB	Judgeable
What is n, Daddy?Count the ordered pairs (a, b) with 1 <= b <= a <= 5 and possibly a single hand, summing to n.	Easy2	MathBrute force+2	No attempts yet	2s	512 MB	Judgeable
Computer PurchaseGiven n computers with RAM, CPU speed, and disk values, sort by the score 2R + 3S + D and print the top two names, breaking ties by smaller name.	Easy2	SortingImplementation	No attempts yet	2s	512 MB	Judgeable
ISBN 1-3-SumGiven the last three digits of an ISBN starting with 9780921418, compute the 1-3-sum and print it.	Easy2	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
Old Fishing HoleGiven three point values and a cap, enumerate every catch with at least one fish whose total points stay within the limit, in a specified order.	Easy2	Brute forceSimulation+1	No attempts yet	1s	128 MB	Judgeable
Good TimesGiven the time in Ottawa as hour*100+minute, print the local time in seven Canadian cities using fixed offsets, wrapping across midnight.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Body Mass IndexRead a weight and a height, compute weight divided by height squared, and print the BMI category.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Do the ShuffleSimulate a fixed 5-song playlist through button presses that rotate left, rotate right, or swap the first two songs, then print the final order.	Easy2	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
It's Cold Here!Read city names with integer temperatures, one per line, and print the name of the city with the lowest temperature.	Easy2	ImplementationArray+2	No attempts yet	1s	128 MB	Judgeable
Who is in the middle?Given the weights of three bowls, print the middle value among the three weights.	Easy2	SortingImplementation	No attempts yet	1s	128 MB	Judgeable
I Speak TXTMSGRead lines until TTYL, map each known short form through a fixed table, and echo other lines unchanged.	Easy2	Hash mapString+1	No attempts yet	1s	128 MB	Judgeable
Deal or No Deal CalculatorRead eliminated case numbers and a Banker's offer, compute the average of the remaining amounts, and print deal if the offer is higher, otherwise no deal.	Easy2	ImplementationArray+1	No attempts yet	1s	128 MB	Judgeable
Anagram CheckerDecide whether two phrases are anagrams, ignoring spaces and letters only.	Easy2	Hash mapString+1	No attempts yet	1s	128 MB	Judgeable
Federal Voting AgeFor each birth date, decide whether the person is at least 18 years old on February 27, 2007.	Easy2	ImplementationMath	No attempts yet	1s	128 MB	Judgeable
The Cell SellGiven daytime, evening, and weekend minutes, compute the monthly cost under two phone plans and print the cheaper one.	Easy2	ImplementationMath+1	No attempts yet	1s	128 MB	Judgeable
Snow CallsConvert each alphanumeric phone number to digits, keep the first 10 digits, and print them in xxx-xxx-xxxx form.	Easy2	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
Mouse MoveThe cursor starts at (0,0) on a screen of width c and height r; each relative move is clamped to the screen edges, and the position after every move must be printed.	Easy2	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
SquaresGiven a number of tiles, find the largest integer side length whose square does not exceed that number.	Easy2	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
Terms of OfficePrint every year from X to Y in which all four offices change, which happens on multiples of lcm(4,2,3,5) = 60, formatted as a fixed sentence.	Easy2	MathImplementation+2	No attempts yet	1s	128 MB	Judgeable
Smile with SimilesGiven up to five adjectives and five nouns, print every phrase of the form "<adjective> as <noun>" in nested input order.	Easy2	ImplementationBrute force+2	No attempts yet	1s	128 MB	Judgeable
Simple EncryptionRemove non-letters from a message and shift each letter within its column by the alphabet position of the keyword letter above it.	Easy2	StringSimulation+1	No attempts yet	1s	128 MB	Judgeable
TridentPrint an ASCII trident with t tine rows, a crossbar, and h handle rows, using spacing s between the tines.	Easy2	ImplementationString+2	No attempts yet	1s	128 MB	Judgeable
Constrained PermutationsCount permutations of 1..n (n at most 9) that satisfy given ordering constraints x before y.	Easy2	Brute forceCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
0123456789Read one digit from 0 to 9 and print it as a seven-segment display drawn with asterisks, three per segment, with no trailing whitespace.	Easy2	ImplementationSimulation+1	No attempts yet	1s	128 MB	Judgeable
AmeriCanadianRead words one per line until the line quit!, and for each word rewrite a trailing consonant followed by or as our when the word has at least five letters.	Easy2	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Fraction ActionReduce a numerator and denominator to simplest form, then print it as a whole number, a proper fraction, or a mixed number.	Easy2	MathNumber theory+1	No attempts yet	1s	128 MB	Judgeable
Dressing UpRead an odd height H and print a bow tie of H rows where each side widens as rows approach the middle.	Easy2	ImplementationSimulation+1	No attempts yet	1s	128 MB	Judgeable
Mod InverseGiven x and m, find n with 0 < n < m such that x*n mod m equals 1, or report that none exists.	Easy2	Number theoryBrute force	No attempts yet	1s	128 MB	Judgeable
CalendarGiven the weekday of the 1st and the number of days, print a month calendar in a fixed weekly layout with right-aligned columns.	Easy2	ImplementationSimulation+1	No attempts yet	1s	128 MB	Judgeable
Cross-Number PuzzlePrint all perfect numbers from 1000 to 9999, then all three-digit numbers equal to the sum of their digits' cubes.	Easy2	Brute forceMath+1	No attempts yet	1s	128 MB	Judgeable
Shift LettersFor each test case, rotate the letters of a word right by n positions and print the result in a fixed sentence format.	Easy2	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
AnagramsGiven two lowercase words, decide whether one can be rearranged into the other, and print the result with the words.	Easy2	StringHash map+1	No attempts yet	1s	128 MB	Judgeable
StringCollapse every run of identical consecutive letters in a lowercase string into a single letter and print the result.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
Making test data 8Print a specific fixed graph: 98 vertices, 1501 edges forming a complete bipartite graph, using the exact listed edge order.	Easy2	GraphImplementation+2	No attempts yet	1s	128 MB	Judgeable
NonogramGiven a grid of black and white squares, print the lengths of the consecutive black blocks in each row and then each column.	Easy2	ImplementationArray+2	No attempts yet	1s	1024 MB	Judgeable
Hidden Roman NumeralsFind which of the twelve Roman numerals from 1 to 12 appear as substrings of a given string over {I,V,X}.	Easy2	StringImplementation+1	No attempts yet	1s	1024 MB	Judgeable
NumbersGiven three distinct digits and one of their six permutations, find that number's 1-based rank when all six permutations are sorted ascending.	Easy2	MathSorting+2	No attempts yet	1s	1024 MB	Judgeable
Building BlocksGiven a target height N and three block heights, pick the kind whose multiples get closest to N, breaking ties by smaller block then shorter tower.	Easy2	MathBrute force	No attempts yet	1s	1024 MB	Judgeable
CardsA 52-card deck is missing exactly one card; given the other 51 cards as suit and value pairs, output the missing suit and value.	Easy2	ArrayHash map+2	No attempts yet	1s	1024 MB	Judgeable
The Worm TurnsSimulate a 20-cell worm on a 50x50 grid through a list of moves, stopping when it hits itself, leaves the board, or finishes.	Easy2	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Counting SheepCount how many words in each list match the string "sheep" exactly, case-sensitive, and print the count per list with blank lines between cases.	Easy2	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
EntropyRead one line of text, count how often each character appears, and print the Shannon entropy rounded to three decimals.	Easy2	Hash mapMath+2	No attempts yet	1s	128 MB	Judgeable
ExpressionGiven N, build a fully parenthesized NAND (Sheffer stroke) expression for the carry-out bit by iterating a fixed string concatenation rule.	Easy2	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Right Triangle CheckFor each of n triples of side lengths, decide whether the triangle is right by checking if the largest side squared equals the sum of the other two squared.	Easy2	MathGeometry+2	No attempts yet	1s	128 MB	Judgeable
Programming Contest PasswordsFor each test case, read a word list and participant index sequences, then print each password formed by concatenating the indexed words.	Easy2	ImplementationArray+1	No attempts yet	1s	128 MB	Judgeable
GaussFor each test case, compute the sum of all integers from n to m inclusive and print the test case number followed by the sum.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
StuPIdGiven an ID with one unknown digit, use the checksum rule to find the missing digit and print the corrected ID.	Easy2	MathImplementation+1	No attempts yet	3s	128 MB	Judgeable
Stacked BowlsGiven a string of parentheses, compute the total stack height where the first bowl adds 10 and each following bowl adds 5 if it matches the previous direction or 10 if it differs.	Easy2	StringSimulation+1	No attempts yet	1s	128 MB	Judgeable
Sexagenary Cycle (干支)Given a year, print its sexagenary cycle name as a branch letter A-L followed by a stem digit 0-9.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
CuboidsFor each cuboid row with one of the four values zeroed out, compute and print the missing length, width, height, or volume.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Jumbled WordsFor each line of lowercase words, keep the first and last letter of every word and reverse the letters in between.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
Untied AirlinesRead each flight's complaint codes, sum the points per passenger, and count how many passengers reach 200 points.	Easy2	ImplementationHash map	No attempts yet	1s	128 MB	Judgeable
MP3 SongsRead several lists of tune names and print each list sorted alphabetically while ignoring case and keeping input order for ties.	Easy2	SortingString+1	No attempts yet	1s	128 MB	Judgeable
BookingsRead a flight's booked-seat count, then apply booking and cancellation lines, ignoring any that would push the count outside 0 to 68, and print the final count.	Easy2	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
How Many Distinct LettersFor each line until the terminator '#', count how many distinct alphabet letters appear, ignoring case and non-letters.	Easy2	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
ExerciseFor each machine, multiply each exercise level's energy rate by its duration and sum the totals per person.	Easy2	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
AAAAHH! Overbooked!Given N event time ranges in hh:mm-hh:mm format, check whether any two events overlap in time.	Easy2	IntervalsSorting	No attempts yet	1s	128 MB	Judgeable
DivisibilityGiven a base-62 string, decide whether the number it represents is divisible by 61.	Easy2	MathNumber theory+1	No attempts yet	1s	128 MB	Judgeable
TeleprimeGiven a six-digit number and a digit to prepend, print Yes if both the original and the resulting seven-digit number are prime.	Easy2	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
JokeCount how many times the substring 'joke' appears in the input text, with line breaks treated as part of the text.	Easy2	StringImplementation	No attempts yet	2s	128 MB	Judgeable
Huffman TreeGiven Z characters and arity N, decode the stored digit string into the per-character encoding.	Easy2	TreeString+1	No attempts yet	3s	128 MB	Judgeable
ConcertRead 10 RGB triples per data set, average each channel, and print the average rounded to the nearest integer.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
The PaintingRead an n by m grid of . and # characters and print it rotated 90 degrees clockwise, producing m rows of n characters.	Easy2	ArrayMatrix+1	No attempts yet	1s	128 MB	Judgeable
Ways to Make RectanglesCount the number of unordered pairs (a, b) with a <= b and a*b <= n.	Easy2	MathBrute force+1	No attempts yet	1s	256 MB	Judgeable
A Cat on a KeyboardGiven a text, replace each character with the keyboard row number (1 to 5) where its key sits.	Easy2	StringImplementation	No attempts yet	1s	128 MB	Judgeable
PolynomialGiven a polynomial's coefficients and an integer x, print the last three digits of \|W(x)\|, padded with leading zeros.	Easy2	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
KamilGiven a word Kamil spoke, count the words he could have meant, since each position may map to one of several letters.	Easy2	MathCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
JulkaGiven the total apples and how many more Klaudia has, compute each girl's count.	Easy2	MathImplementation	No attempts yet	1s	128 MB	Judgeable
Ant NamesGiven up to 100 lowercase names, print the maximum number of distinct letters found in any single name.	Easy2	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable