Strings and text

Parsing, matching, and tries

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Still being built. Things may change

Total results3,614 problems

Gift Expiration Date
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Marathoner
Easy2
Implementation, String
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Yoda and SI Prefixes
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Figurines
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Just Laughter
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Basketball
Easy2
Hash map, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Odin
Easy2
String, Simulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Squad
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Yoda's Speechwriter
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Chemistry
Easy2
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Data Transmission
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Shuffle the inner letters
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Languages
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
GPA Calculator
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Real Number
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Morse Code
Easy2
String, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Beusil's Ttibu-Ttibu Sticker Collection
Easy2
Hash map, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Problems No Larger Than the Weeds
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Character Frequencies
Easy2
Hash map, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Important Messages
Easy2
Hash map, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Unreadable Text
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
ZOAC 6
Easy2
String, String matching
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dešifravimas (Decryption)
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hello, World!
Easy2
String, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Let's Portmanteau
Easy2
String, Implementation
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Hurricane Warning
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Random Number Generator
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Making a Rainbow
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Reverse
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Happiness Score
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Find the Zebra!
Easy2
String, Implementation
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Deciphering WordWhiz
Easy2
Implementation, String
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
ISBN Conversion
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Anti-Palindrome
Easy2
String, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Attendance
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pop-It
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Choosing the Morgorithm President
Easy2
String, Array
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
UOSPC Count
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
NOT a SAT problem
Easy2
Implementation, String
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
X marks the Spot
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Equal Schedules
Easy2
Hash map, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Big Data vs Information Security vs AI
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Let's Go to Jinju! (Hard)
Easy2
Implementation, String
No attempts yet
Time limit
3s
Memory limit
16 MB
Judgeable
Democracy
Easy2
Implementation, String
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Hexadecimal Chaos
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Clever Ines
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sign
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Frequency
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Barabashka
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
#TheDress
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
What Kind of Code Is This..
Easy2
String, Implementation
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
No Birch Here~
Easy2
String, String matching+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Guess the Song from the Intro
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Three Consecutive
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
International Dates
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mean Words
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Special School Escape
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Global Phoenix
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Catching the Troublemakers
Easy2
Simulation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Team Name Selection 2
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
SMUPC NAME
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hyundai Mobis Special Prize 2
Easy2
Brute force, String matching
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
SWAPC
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cool Phone Numbers
Easy2
String, Hash map
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Hamburger Sort
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
ANA is a palindrome
Easy2
String, Brute force
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
BB84
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Osobna
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Leg Day
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dragged-out Duel
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Club Fund Embezzlement
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Akaraka 2
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
f(A + B)
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hamburger
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Which One is Larger
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Su-su-su-supernova
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Alphabetical Aristocrats
Easy2
String, Sorting
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Conference Track Registration
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Waste Separation
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Problem C
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Periodic String
Easy2
String, Brute force
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Glass Reflection
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Encryptastrophy
Easy2
String, Simulation
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Game Night
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Minimum String Difference
Easy3
String, Sliding window+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Strange Multiplication
Easy3
Math, String+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Student Numbers
Easy3
String, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Binary Addition
Easy3
String, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Make a Palindrome
Easy3
String, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Shortcut Key Assignment
Easy3
Simulation, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Binary to Octal Conversion
Easy3
Bit manipulation, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Messages
Easy3
Simulation, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Serial Numbers
Easy3
Sorting, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Lost Parentheses
Easy3
Greedy, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Cyclic Words
Easy3
String, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
I Am Pokemon Master Dasom
Easy3
Hash map, Implementation+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Common Permutation
Easy3
Hash map, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Lucky Ticket
Easy3
Prefix sum, Brute force+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
DNA Decoding
Easy3
Simulation, String+1
No attempts yet
Time limit
5s
Memory limit
16 MB
Judgeable
Crossword
Easy3
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Gift Expiration DateCount how many gift cards have an expiration date later than the current date, with dates in YYYY-MM-DD form and no leap years.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
MarathonerSum n song durations given as mm:ss and print the total run length in hh:mm:ss format.	Easy2	ImplementationString	No attempts yet	2s	1024 MB	Judgeable
Yoda and SI PrefixesGiven a word of stacked SI prefixes followed by meter, meter^2, or meter^3, output the power of ten x that the unit equals in base SI units.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
FigurinesGiven n figurines each facing N, S, W, or E, find the fewest turns needed to make all of them face the same direction.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Just LaughterFind the length of the longest substring made of alternating letters a and h in a string of up to 100,000 lowercase letters.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
BasketballGiven a log of score changes in two hoops, find the player who scored the most points and report that total.	Easy2	Hash mapImplementation+1	No attempts yet	1s	1024 MB	Judgeable
OdinGiven a bracketed formula, the task rewrites first-level brackets as curly braces, second-level as square brackets, and deeper ones as round brackets.	Easy2	StringSimulation	No attempts yet	2s	1024 MB	Judgeable
SquadGiven two equal-length digit strings a and b, print the string that takes the larger digit at each position.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Yoda's SpeechwriterReverse the word order in each period-terminated sentence of a line of lowercase words, keeping the periods and single spaces.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
ChemistryGiven a chemical formula with C, H, N, O and counts, the task is to print the total molar mass using fixed atomic weights.	Easy2	StringImplementation+1	No attempts yet	2s	1024 MB	Judgeable
Data TransmissionGiven two binary strings s and t, the task is to decide whether t equals s or differs from it by one swap of adjacent bits.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Shuffle the inner lettersGiven a text, shuffle the inner letters of each word while keeping the first and last letters fixed, leaving words unchanged when no different arrangement exists.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
LanguagesGiven names for digits 0 to 9, find for each number the digit in it whose name comes last in alphabetical order.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
GPA CalculatorGiven a string of concatenated letter grades such as A+ and B, print the arithmetic mean of their grade points.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
Real NumberGiven a real number x with 0 <= x < 1 and an integer k, round x to k digits after the decimal point, carrying 9s upward as needed.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
Morse CodeGiven a Morse code message with characters separated by spaces, the task is to decode it back into the original string of length N.	Easy2	StringHash map+1	No attempts yet	1s	1024 MB	Judgeable
Beusil's Ttibu-Ttibu Sticker CollectionGiven N uppercase letter stickers, find how many full copies of the word BRONZESILVER can be spelled from them.	Easy2	Hash mapString	No attempts yet	1s	1024 MB	Judgeable
Problems No Larger Than the WeedsCount how many problems have a total character size no greater than the weed size J, where uppercase letters are 4, lowercase letters and digits are 2, and spaces are 1.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Character FrequenciesCount how many times each non-whitespace character appears in N lines of text and print each character with its count.	Easy2	Hash mapString	No attempts yet	1s	1024 MB	Judgeable
Important MessagesCount how many message sender addresses appear in a given contact list of email addresses.	Easy2	Hash mapString	No attempts yet	1s	1024 MB	Judgeable
Unreadable TextGiven N topics and a pattern where '*' marks each unreadable letter, list every topic that matches the pattern in input order.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
ZOAC 6Count the sentences that contain the substring 01 or OI, since each such sentence gets one Yeongil emoticon.	Easy2	StringString matching	No attempts yet	1s	1024 MB	Judgeable
Dešifravimas (Decryption)Given a partly encrypted Caesar cipher message and the full encrypted message, find the key from the first differing letter and decrypt the full message.	Easy2	StringSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Hello, World!Given N SPAUSDINTI commands, print the text inside each pair of quotes in order, turning the newline marker into a line break.	Easy2	StringSimulation	No attempts yet	1s	1024 MB	Judgeable
Let's PortmanteauGiven two words, build a portmanteau from the first word's leading consonants, one merging vowel, and the second word's trailing consonants, then print it.	Easy2	StringImplementation	No attempts yet	5s	1024 MB	Judgeable
Hurricane WarningFor each data set, count the people whose consumed media string shares at least one letter with the media string the authorities use for the warning.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Random Number GeneratorGiven N digits drawn as 9 by 8 pictures of dots and hashes, print the number those digits form.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Making a RainbowGiven a string of letters, decide whether it has enough lowercase, uppercase, or both to spell ROYGBIV, then print yes, YES, YeS, or NO!.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
ReverseGiven six output lines from related problems, print one possible input for each problem in order.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
Happiness ScoreGiven one message, count letters that appear in HAPPY and SAD, then print the happiness index as a percentage rounded to two decimals.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Find the Zebra!Count the runs of 1s in each zebra's coat string, then print the maximum run count and how many zebras reach it.	Easy2	StringImplementation	No attempts yet	0.5s	1024 MB	Judgeable
Deciphering WordWhizGiven the secret word and the feedback for each guess, count the dictionary words that would produce that exact feedback against the secret.	Easy2	ImplementationString	No attempts yet	0.5s	1024 MB	Judgeable
ISBN ConversionGiven ISBN-10 strings that may contain hyphens, check each one's placement and checksum, then print the ISBN-13 with 978 prepended or print invalid.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Anti-PalindromeGiven one line of text, decide whether it contains a palindrome of two or more letters after ignoring non-letters and case.	Easy2	StringBrute force	No attempts yet	1s	1024 MB	Judgeable
AttendanceGiven a log of called names and Present! replies, print the names of students who never answered Present!, in the order they were called.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Pop-ItGiven an h by w grid of 0s and 1s, find the fewest cells to flip so that every cell has the same value.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Choosing the Morgorithm PresidentGiven N distinct uppercase names, print the one that comes first in dictionary order among those with exactly three characters.	Easy2	StringArray	No attempts yet	1s	1024 MB	Judgeable
UOSPC CountRearrange the letters of S to form as many copies of uospc as possible, and print that maximum count.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
NOT a SAT problemFind a truth assignment that makes the given CNF false, or report NO if every clause contains both a variable and its negation.	Easy2	ImplementationString	No attempts yet	2s	1024 MB	Judgeable
X marks the SpotFor each string pair, find the position of x or X in S and output the letter at that position in T, uppercased, concatenated in order.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Equal SchedulesGiven two on-call schedules, print how much each teammate's on-call time changed from the first schedule to the second, sorted by name.	Easy2	Hash mapImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Big Data vs Information Security vs AIGiven a string of B, S, and A answers, output the most frequent letter, listing tied letters in B, S, A order or SCU if all three tie.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
Let's Go to Jinju! (Hard)Given N transport options with destinations and fares, print the fare to jinju and how many options cost more than that fare.	Easy2	ImplementationString	No attempts yet	3s	16 MB	Judgeable
DemocracyCount the candidates that get more than half of the M votes in favor, where each candidate's votes are given as a string of O and X.	Easy2	ImplementationString	No attempts yet	0.5s	1024 MB	Judgeable
Hexadecimal ChaosGiven a shortened IPv6 address, expand it to the full notation of 8 groups of 4 hexadecimal digits separated by colons.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Clever InesReverse a column-by-column reading of an r x s grid (r at most s, r*s = n, r as large as possible) to recover the original message.	Easy2	ImplementationString+1	No attempts yet	1s	1024 MB	Judgeable
SignGiven three prices, print the sign text in input order, writing a shared digit once with an apostrophe when one price ends in the digit the next price starts with.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
FrequencyCount how often each Latin letter appears, ignoring case, in text that ends with @, and print a vertical bar chart with the letters A to Z along the bottom.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
BarabashkaGiven five card descriptions, print the color and name of the item to grab for each card by checking which items and colors the sentence mentions.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
#TheDressFor each survey answer, checks whether it contains the word pair blue and black, white and gold, or neither, then prints the three population percentages.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
What Kind of Code Is This..Given a string with at most two double quotes, print the text between the quotes if it is a valid quoted string, or print CE otherwise.	Easy2	StringImplementation	No attempts yet	0.5s	1024 MB	Judgeable
No Birch Here~Given N item names with quantities, sum the quantities of every item whose name contains the substring S.	Easy2	StringString matching+1	No attempts yet	1s	1024 MB	Judgeable
Guess the Song from the IntroGiven stored songs with their first seven notes, for each query of three notes, print the unique song title starting with those notes, ? if several match, or ! if none.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Three ConsecutiveGiven a string of 'o' and 'x' characters, the task is to check whether three 'o' characters appear consecutively.	Easy2	StringImplementation	No attempts yet	2s	1024 MB	Judgeable
International DatesGiven a date written as AA/BB/CCCC, decide whether it must be US format (MM/DD), must be European format (DD/MM), or could be either.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Mean WordsGiven N words, build one word by taking the floor of the average ASCII value at each position across the words that reach that position.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Special School EscapeGiven N teacher patrol strings over M periods, find the earliest period when no teacher patrols, or report ESCAPE FAILED if none exists.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Global PhoenixGiven three strings, check whether they can be ordered so that they start with l, k, and p respectively, and print GLOBAL or PONIX.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Catching the TroublemakersFor each member's solve record over M days, find the longest run of days without a solve, then count how many distinct longest-run values there are.	Easy2	SimulationString	No attempts yet	1s	1024 MB	Judgeable
Team Name Selection 2Given N candidate team names, print the one that has at most 10 characters, no more uppercase than lowercase letters, and at least one non-digit character.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
SMUPC NAMEGiven a registration number and a lowercase name, the task builds a SMUPC NAME by deduplicating letters, appending a count, prepending a number, and reversing the result.	Easy2	StringSimulation+1	No attempts yet	1s	512 MB	Judgeable
Hyundai Mobis Special Prize 2Count how many times the word MOBIS can be read in an N by N letter grid, starting from any cell and moving in one of 8 directions.	Easy2	Brute forceString matching	No attempts yet	1s	1024 MB	Judgeable
SWAPCGiven a string, pair the i-th P with the i-th C in order, swap the two characters in each pair, and print the resulting string.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Cool Phone NumbersGiven a US phone number in ddd-ddd-dddd format, count how many distinct digits it contains.	Easy2	StringHash map	No attempts yet	5s	1024 MB	Judgeable
Hamburger SortGiven a length-3 string holding (, 1, and ) once each, find the fewest moves that place one character next to another to form (1).	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
ANA is a palindromeCount the substrings of S that start and end with A, contain exactly one N, and have no other A.	Easy2	StringBrute force	No attempts yet	1s	1024 MB	Judgeable
BB84Given each qubit's basis and value from both sides, build the shared key from positions where the bases match, or print htg! if any matched position disagrees.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
OsobnaGiven three 30-character ID card lines, extract the first name, last name, birth date, and PIN, then print them in a fixed Croatian label format.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Leg DayClassify each day of a repeating exercise plan as rest, leg, or arm by keyword, then print a Monday-start 31-day calendar of matching pictographs over 5 weeks.	Easy2	StringSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Dragged-out DuelGiven two strings of rock-paper-scissors choices over n rounds, output whether you or Guile wins more rounds.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Club Fund EmbezzlementGiven a string of at most 8 characters, decide whether it has the form n+n for a positive integer n that does not start with 0.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Akaraka 2Given K, print the shortest string in which AKARAKA appears as a contiguous substring exactly K times.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
f(A + B)Given a one-to-one digit mapping f and the images f(A) and f(B), compute f(A+B) for positive integers A and B up to 10^7.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
HamburgerGiven a string S of bread, patty, lettuce, and tomato, check whether it is a valid hamburger: bread at both ends, no equal neighbors, and counts within A, B, C, D.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Which One is LargerGiven two decimals, print the larger one if comparing them as integer tuples (integer part, then fraction digits) agrees with normal decimal order, otherwise print -1.	Easy2	StringImplementation	No attempts yet	1s	2048 MB	Judgeable
Su-su-su-supernovaGiven a year N and its discovery order M, print the supernova name: SN, the year, then the order written as A to Z, followed by aa to zz.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Alphabetical AristocratsGiven n surnames, sort them by the substring starting at the first capital letter, using ASCII order, and print the full names.	Easy2	StringSorting	No attempts yet	2s	1024 MB	Judgeable
Conference Track RegistrationGiven a paper topic, print which conference track to join by checking which track's keyword appears in the topic.	Easy2	StringImplementation	No attempts yet	1s	2048 MB	Judgeable
Waste SeparationFor each trash string, pick the cheaper option: its recycling bin if it is one recyclable type, otherwise general waste, and sum the minimum costs.	Easy2	ImplementationString	No attempts yet	1s	1024 MB	Judgeable
Problem CGiven N words, replace each c with k or s by its English pronunciation rule, and replace each ch with c.	Easy2	StringImplementation	No attempts yet	1s	2048 MB	Judgeable
Periodic StringGiven a string S of length N, the task is to check whether S is some string T repeated at least twice, printing Yes or No.	Easy2	StringBrute force	No attempts yet	2s	2048 MB	Judgeable
Glass ReflectionGiven a reflected string where each run of identical letters is one letter longer than in the original, output the original word.	Easy2	StringImplementation	No attempts yet	1s	2048 MB	Judgeable
EncryptastrophyGiven a ciphertext where each letter is the mod 26 sum of a plaintext letter and the plaintext letter before it, plus the last plaintext letter, recover the full plaintext.	Easy2	StringSimulation	No attempts yet	1s	2048 MB	Judgeable
Game NightGiven two equal-length passwords, count the positions where the letters differ, since only those magnets must be fetched from the box.	Easy2	StringImplementation	No attempts yet	2s	2048 MB	Judgeable
Minimum String DifferenceSlide the shorter string A across every possible alignment position over B and output the minimum number of mismatched characters.	Easy3	StringSliding window+1	No attempts yet	2s	128 MB	Judgeable
Strange MultiplicationGiven two large numbers as digit strings, compute the sum of all pairwise products of their digits, which equals the product of their digit sums.	Easy3	MathString+1	No attempts yet	2s	256 MB	Judgeable
Student NumbersGiven N equal-length numeric strings, find the smallest suffix length k so that all suffixes of length k remain distinct.	Easy3	StringBrute force+1	No attempts yet	2s	128 MB	Judgeable
Binary AdditionAdd two binary strings up to 80 digits long and print the sum in binary without leading zeros.	Easy3	StringMath+1	No attempts yet	2s	128 MB	Judgeable
Make a PalindromeGiven a lowercase string of length at most 50, find the minimum length of a palindrome obtained by appending characters only to its end.	Easy3	StringBrute force+1	No attempts yet	2s	128 MB	Judgeable
Shortcut Key AssignmentAssign each menu option an unused shortcut letter by checking word-initial letters first, then any letter in the string, following the options in order.	Easy3	SimulationString+1	No attempts yet	2s	128 MB	Judgeable
Binary to Octal ConversionConvert a binary number with up to 1,000,000 digits into its octal representation.	Easy3	Bit manipulationMath+2	No attempts yet	1s	128 MB	Judgeable
MessagesGiven sheets of names passed around a circle with P/N marks, find who wrote each hurtful (N) message and about whom.	Easy3	SimulationArray+2	No attempts yet	1s	128 MB	Judgeable
Serial NumbersSort serial numbers by length, then digit-sum, then a custom lexicographic rule where digits precede letters.	Easy3	SortingString+1	No attempts yet	2s	128 MB	Judgeable
Lost ParenthesesGiven an arithmetic expression with only plus and minus signs, place parentheses to minimize the evaluated result.	Easy3	GreedyString+1	No attempts yet	2s	128 MB	Judgeable
Cyclic WordsCount how many words are distinct once each is allowed to be read starting from any position around a circle.	Easy3	StringBrute force+1	No attempts yet	2s	128 MB	Judgeable
I Am Pokemon Master DasomBuild a bidirectional mapping between Pokemon numbers and names, then answer up to 100,000 lookup queries either way.	Easy3	Hash mapImplementation+1	No attempts yet	2s	256 MB	Judgeable
Common PermutationFor each pair of input strings, count letter frequencies and output the multiset intersection sorted alphabetically as the longest common rearranged subsequence.	Easy3	Hash mapString+1	No attempts yet	2s	128 MB	Judgeable
Lucky TicketFind the longest even-length substring of a digit string whose first half digit sum equals its second half digit sum.	Easy3	Prefix sumBrute force+2	No attempts yet	2s	128 MB	Judgeable
DNA DecodingRepeatedly merge the last two bases of a DNA string using a fixed lookup table until one base remains, then output it.	Easy3	SimulationString+1	No attempts yet	5s	16 MB	Judgeable
CrosswordGiven a filled crossword grid, extract every maximal horizontal or vertical run of letters of length at least two and output the lexicographically smallest such word.	Easy3	StringImplementation+1	No attempts yet	2s	128 MB	Judgeable