Strings and text

Parsing, matching, and tries

Under construction

Still being built. Things may change

Total results3,614 problems

Palindrome Lines
Easy2
Two pointers, String
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Word Swap
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Odysseus and the Sirens
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Amino Acid
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Headshot
Easy2
Probability, String
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Radix 32 Conversion
Easy2
Math, String
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Pangram Checker
Easy2
String, Hash map
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
The return of the King
Easy2
String, Greedy
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Working Hours
Easy2
Implementation, String+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Rövarspråket
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Comma Separated Sum
Easy2
String, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Veni, vidi, vici
Easy2
String, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Spring 2005: Arriving at USC
Easy2
Two pointers, String matching
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Pattern Word Banking
Easy2
Simulation, String
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Kkung's Girlfriend Plan
Easy2
Implementation, Hash map+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Letter Cookies
Easy2
Hash map, String
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Is It a Number?
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Decode the Message
Easy2
String, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Password
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Cypher
Easy2
String, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Coverity Crossword
Easy2
String matching, Matrix+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Eakspay igpay atinlay?
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Hash Code Hacker
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Spin the number wheel
Easy2
Brute force, String
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Hidden Password
Easy2
Simulation, String
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Marko's T9 input
Easy2
String, Hash map
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Identifying Map Tiles
Easy2
Bit manipulation, String
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
YODA
Easy2
String, Simulation
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Lazy Spelling Bee (Large)
Easy2
Combinatorics, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Moist (Small1)
Easy2
Array, String
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Hangul Initial Consonants
Easy2
Math, String+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
#include <Google I/O.h>
Easy2
Implementation, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Read Phone Number (Small)
Easy2
Simulation, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Fair and Square (Small)
Easy2
Brute force, Math+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Proprietary Problem
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Reverse Word Order
Easy2
String, Implementation
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Reverse Words (Large)
Easy2
String, Implementation
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
T9 Spelling (Small)
Easy2
String, Implementation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Immigrate to the CTP principality
Easy2
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bitwise Operations on Binary Numbers
Easy2
String, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cameras
Easy2
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Adding god to nicknames
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Palindrome
Easy2
String, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
A New Alphabet
Easy2
String, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Quick Estimates
Easy2
String, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Math Contest
Easy2
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Four Arithmetic Operations
Easy2
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Boys and Girls
Easy2
Implementation, Brute force+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
The Funniest Digital Laughter
Easy2
String, Two pointers
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Holes
Easy2
String, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Virus
Easy2
String, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Alpha Puzzle
Easy2
Simulation, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Luhn Algorithm
Easy2
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bridge Honor Points
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
Country Leader (Small)
Easy2
String, Implementation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Country Leader
Easy2
String, Sorting+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Refreshment Area
Easy2
Array, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Birthday Graph
Easy2
Array, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Grid Pattern
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
X X glued
Easy2
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hongjun surrounded by fans
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Empathy
Easy2
Math, String+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Credit Card Validation
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
No Duplicates
Easy2
String, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Boolean Satisfiability
Easy2
Combinatorics, Math+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Atomic Mass
Easy2
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Kiwis vs Kangaroos
Easy2
Implementation, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Beautiful Music
Easy2
Implementation, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Letter Count
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Pirates
Easy2
String, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Password check
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hissing Microphone
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Life Score
Easy2
String, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Big number A+B
Easy2
String, Math+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Check the Check
Easy2
Implementation, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lorem ipsum
Easy2
String, Implementation+1
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
Hash collision strings
Easy2
String, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Binary Game
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Rick
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Derivative of a polynomial function
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Master of the Shell Game
Easy2
String, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
What Is Your Handle
Easy2
Sorting, String+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Caesar Cipher
Easy2
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
What Does UCPC Stand For?
Easy2
String, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Occupy Parking
Easy2
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Baby Bites
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
CPU
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Run-Length Encoding, Run!
Easy2
String, Simulation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Time to Decompress
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
XORChic
Easy2
Implementation, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
99 Bottles of Beer
Easy2
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cute Number~ε٩(๑> ₃ <)۶з
Easy2
Implementation, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
What's the Second Baseman's Name
Easy2
Implementation, String
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bonus Score
Easy2
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
What Is a Recursive Function?
Easy2
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
369
Easy2
Implementation, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mangling Names
Easy2
Implementation, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Command
Easy2
String, Implementation+1
No attempts yet
Time limit
0.5s
Memory limit
256 MB
Judgeable
Regional Team Names
Easy2
String, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pea Soup and Pancakes
Easy2
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Palindrome LinesDecide for each of n short lines whether it reads the same forward and backward, ignoring letter case.	Easy2	Two pointersString	No attempts yet	1s	256 MB	Judgeable
Word SwapSum the per-position letter differences between each pair of equal-length words and report the coins earned, paid, or free.	Easy2	ImplementationString	No attempts yet	1s	256 MB	Judgeable
Odysseus and the SirensThe program scores every melody under each candidate key by summing note penalties and prints the numbered key with the smallest total.	Easy2	ImplementationString+1	No attempts yet	1s	256 MB	Judgeable
Amino AcidParse each formula into element counts and print the molecular weight, or Invalid formula for other elements.	Easy2	StringImplementation	No attempts yet	1s	64 MB	Judgeable
HeadshotAfter a click on a circular cylinder, compare firing at once against spinning first and print which choice is safer.	Easy2	ProbabilityString	No attempts yet	1s	64 MB	Judgeable
Radix 32 ConversionConvert each base-32 string of up to 8 digits to its decimal value and to binary by expanding every digit to 5 bits.	Easy2	MathString	No attempts yet	1s	64 MB	Judgeable
Pangram CheckerCount how many times each English letter appears in every sentence and print its pangram grade.	Easy2	StringHash map	No attempts yet	3s	256 MB	Judgeable
The return of the KingSplit the digit string into grades of 1 to 10 in the single valid way and print the average rounded to two decimals.	Easy2	StringGreedy	No attempts yet	1s	256 MB	Judgeable
Working HoursAdd signed hour and minute terms in a flexible format and print each total as H:MM.	Easy2	ImplementationString+1	No attempts yet	2s	256 MB	Judgeable
RövarspråketTranslate one lowercase word by expanding each consonant into three letters under the given vowel and consonant rules.	Easy2	ImplementationString	No attempts yet	1s	256 MB	Judgeable
Comma Separated SumAdd all the natural numbers listed in the comma-separated string S.	Easy2	StringMath	No attempts yet	1s	256 MB	Judgeable
Veni, vidi, viciDrop the last letter of each odd-length ciphertext, then decode every letter pair into one plain letter with the given key.	Easy2	StringMath	No attempts yet	1s	256 MB	Judgeable
Spring 2005: Arriving at USCFilter the building list to names that hold the abbreviation letters as a case-insensitive subsequence and print the matches in input order.	Easy2	Two pointersString matching	No attempts yet	1s	256 MB	Judgeable
Pattern Word BankingAdd the PIN digits picked by lowercase pattern letters and print non sequitur if the letter values do not match the PIN length.	Easy2	SimulationString	No attempts yet	2s	256 MB	Judgeable
Kkung's Girlfriend PlanEach test case gives named condition times and AND-OR combos, and the answer is the smallest combo time where one combo takes its slowest condition.	Easy2	ImplementationHash map+1	No attempts yet	1s	256 MB	Judgeable
Letter CookiesGiven the letters in a box, decide for each query word whether its letters can all be taken from the box.	Easy2	Hash mapString	No attempts yet	1s	256 MB	Judgeable
Is It a Number?Check whether each line holds only digits with optional surrounding spaces and print the number without leading zeros or invalid input.	Easy2	StringImplementation	No attempts yet	1s	256 MB	Judgeable
Decode the MessageThe program decodes each word into one character from its letter values modulo 27.	Easy2	StringMath+1	No attempts yet	1s	256 MB	Judgeable
PasswordCheck whether the two letters typed into the blanked positions of a stored answer match the letters at those positions, ignoring spaces.	Easy2	StringImplementation	No attempts yet	1s	256 MB	Judgeable
CypherDecrypt each message line by shifting its lowercase letters back by the Caesar shift computed from its date.	Easy2	StringMath	No attempts yet	1s	256 MB	Judgeable
Coverity CrosswordDecide whether every listed word appears horizontally, vertically, or diagonally in an 8 by 8 letter grid.	Easy2	String matchingMatrix+1	No attempts yet	2s	256 MB	Judgeable
Eakspay igpay atinlay?Translate each phrase into Pig Latin by moving each leading consonant cluster to the end with ay, or adding yay after vowel-initial words.	Easy2	StringImplementation	No attempts yet	1s	256 MB	Judgeable
Hash Code HackerThe program prints k distinct letter strings that share one Java hash code by mapping binary digits to Aa and BB blocks.	Easy2	StringImplementation	No attempts yet	2s	256 MB	Judgeable
Spin the number wheelCount the wheel positions where the M digits read clockwise form a number between X and Y.	Easy2	Brute forceString	No attempts yet	1s	256 MB	Judgeable
Hidden PasswordDecide if scanning the message and skipping letters outside the remaining password set reproduces the password in order.	Easy2	SimulationString	No attempts yet	1s	256 MB	Judgeable
Marko's T9 inputCount how many dictionary words map letter by letter to the given T9 digit string.	Easy2	StringHash map	No attempts yet	2s	64 MB	Judgeable
Identifying Map TilesConvert a map tile quadkey into its zoom level and x and y coordinates.	Easy2	Bit manipulationString	No attempts yet	1s	256 MB	Judgeable
YODACompare two numbers digit by digit from the right and drop the smaller digit at each position, printing YODA for a number left with no digits.	Easy2	StringSimulation	No attempts yet	1s	64 MB	Judgeable
Lazy Spelling Bee (Large)Count distinct words formed by picking each letter from its neighbors in the target word, modulo 1e9+7.	Easy2	CombinatoricsString+1	No attempts yet	5s	512 MB	Judgeable
Moist (Small1)For each deck of names, count how many cards the robot moves to sort the deck into lexicographic order.	Easy2	ArrayString	No attempts yet	5s	512 MB	Judgeable
Hangul Initial ConsonantsPrint the initial consonant of each Hangul syllable in the given string in order.	Easy2	MathString+1	No attempts yet	1s	512 MB	Judgeable
#include <Google I/O.h>Decode each block of eight I and O letters as one ASCII byte and print the message for every test case.	Easy2	ImplementationString+1	No attempts yet	5s	512 MB	Judgeable
Read Phone Number (Small)Split each digit string into the given group lengths and read each run of equal digits with count words such as double and triple.	Easy2	SimulationString+1	No attempts yet	5s	512 MB	Judgeable
Fair and Square (Small)Count numbers in each interval [A, B] that are palindromes and squares of palindromes.	Easy2	Brute forceMath+1	No attempts yet	5s	512 MB	Judgeable
Proprietary ProblemA product key entry field is shown; the task appears to require validating or generating a key in the format XXXXX-XXXXX-XXXXX-XXXXX-XXXXX.	Easy2	StringImplementation	No attempts yet	1s	1024 MB	Judgeable
Reverse Word OrderGiven N lines of space-separated words, print each line's words in reverse order prefixed with the case number.	Easy2	StringImplementation	No attempts yet	5s	512 MB	Judgeable
Reverse Words (Large)Read each line of words and print the words in reverse order, prefixed by the case number.	Easy2	StringImplementation	No attempts yet	5s	512 MB	Judgeable
T9 Spelling (Small)Map each letter of a short message to its keypad digit and repeat count, inserting a space between consecutive letters that share the same key.	Easy2	StringImplementation+2	No attempts yet	5s	512 MB	Judgeable
Immigrate to the CTP principalityConvert each item between uppercase letters and their alphabet positions (A=1 to Z=26), in the direction given by the mode character.	Easy2	ImplementationString+2	No attempts yet	1s	128 MB	Judgeable
Bitwise Operations on Binary NumbersGiven two equal-length binary strings, output their bitwise AND, OR, XOR, and the complemented forms of each, keeping length and leading zeros.	Easy2	StringBit manipulation+1	No attempts yet	2s	512 MB	Judgeable
CamerasRead n eight-character plates and print each one that matches a fixed pattern of digits and a capital letter, in input order.	Easy2	StringImplementation+1	No attempts yet	2s	512 MB	Judgeable
Adding god to nicknamesGiven N nicknames split into syllables by spaces, replace the first syllable with god and print the result.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
PalindromeGiven a lowercase word of at most 20 characters, decide whether it reads the same forwards and backwards.	Easy2	StringTwo pointers+1	No attempts yet	2s	512 MB	Judgeable
A New AlphabetReplace each English letter with its fixed symbol string from a 26-entry table, leaving all other characters unchanged.	Easy2	StringHash map+1	No attempts yet	2s	512 MB	Judgeable
Quick EstimatesRead N integers up to 10^100 and print the number of digits in each, counting 0 as one digit.	Easy2	StringMath+1	No attempts yet	2s	512 MB	Judgeable
Math ContestGiven a huge decimal integer x, print YES if x is divisible by 9 and NO otherwise.	Easy2	Number theoryMath+1	No attempts yet	1s	512 MB	Judgeable
Four Arithmetic OperationsEach line gives an expression a op b = c with single-digit spacing, and you print correct or wrong answer depending on whether the arithmetic matches the claimed result.	Easy2	MathImplementation+2	No attempts yet	1s	128 MB	Judgeable
Boys and GirlsArrange n children in a circle with B/G so that exactly x stand next to a boy and exactly y next to a girl, output the lexicographically smallest.	Easy2	ImplementationBrute force+1	No attempts yet	2s	256 MB	Judgeable
The Funniest Digital LaughterGiven a string, ignore the consonants and decide whether the remaining vowels read the same forwards and backwards.	Easy2	StringTwo pointers	No attempts yet	1s	512 MB	Judgeable
HolesCount the holes in each of N lines of uppercase text, where B counts as two, A D O P Q R count as one, and the rest count as zero.	Easy2	StringImplementation+2	No attempts yet	2s	512 MB	Judgeable
VirusGiven a key and one line of ciphertext, undo a Caesar variant whose shift grows by one per letter and resets after 25.	Easy2	StringSimulation+1	No attempts yet	2s	512 MB	Judgeable
Alpha PuzzleAssign numbers 1 to 26 to letters by scanning the grid and numbering each letter at its first appearance.	Easy2	SimulationString+1	No attempts yet	2s	512 MB	Judgeable
Luhn AlgorithmGiven a sixteen-digit card number as a string, check whether it passes the Luhn checksum and print DA or NE.	Easy2	StringImplementation+2	No attempts yet	1s	512 MB	Judgeable
Bridge Honor PointsGiven N strings of 13 card characters, add up honor points (A=4, K=3, Q=2, J=1) across all hands and print the total.	Easy2	ImplementationString+1	No attempts yet	1s	32 MB	Judgeable
Country Leader (Small)For each test case, find the name with the most distinct letters, breaking ties by ASCII alphabetical order, and print it.	Easy2	StringImplementation+2	No attempts yet	5s	512 MB	Judgeable
Country LeaderFor each test case, pick the name with the most distinct letters, breaking ties by lexicographic order where a space sorts before any letter.	Easy2	StringSorting+2	No attempts yet	5s	512 MB	Judgeable
Refreshment AreaCount the number of D-long horizontal or vertical runs of empty cells in an N by M grid.	Easy2	ArrayImplementation+2	No attempts yet	2s	512 MB	Judgeable
Birthday GraphRead dates in dd mm yyyy form and print a star per birthday for each of the twelve months, in a numbered case format.	Easy2	ArrayString+1	No attempts yet	5s	512 MB	Judgeable
Grid PatternFor each case, print a text grid with pipe, minus, and plus lines and asterisk-filled cells of size w by h.	Easy2	ImplementationSimulation+1	No attempts yet	10s	512 MB	Judgeable
X X gluedFor each registration number, print every run of two or more identical digits in the four-digit group, in left-to-right order.	Easy2	StringImplementation+1	No attempts yet	2s	512 MB	Judgeable
Hongjun surrounded by fansGiven Hongjun's id, print a 3 by 3 grid of emoticons with :id: in the center and :fan: in the other eight cells.	Easy2	ImplementationString	No attempts yet	1s	64 MB	Judgeable
EmpathyMultiply two binary numbers up to 30 bits long and print the product in binary without leading zeros.	Easy2	MathString+2	No attempts yet	2s	256 MB	Judgeable
Credit Card ValidationFor each 16-digit card number, apply the Luhn checksum (double every second digit from the right, sum digits) and print T if the total is divisible by 10, else F.	Easy2	ImplementationString+1	No attempts yet	1s	128 MB	Judgeable
No DuplicatesRead a line of space-separated uppercase words and print yes if no word repeats, or no if any word appears more than once.	Easy2	StringHash map+1	No attempts yet	2s	512 MB	Judgeable
Boolean SatisfiabilityCount the assignments of a disjunction of single literals that make the formula true, where each variable takes true or false.	Easy2	CombinatoricsMath+2	No attempts yet	3s	512 MB	Judgeable
Atomic MassParse a short chemical formula, look up each element's atomic mass, multiply by any following count, and print the total with two decimals.	Easy2	StringHash map+2	No attempts yet	1s	512 MB	Judgeable
Kiwis vs KangaroosGiven a phrase, score each side by how often its letters appear in KANGAROO or KIWIBIRD, then report the higher score or a tie.	Easy2	ImplementationString+2	No attempts yet	2s	512 MB	Judgeable
Beautiful MusicFor each note sequence, check whether every consecutive pair is 2, 4, or 6 steps apart on the repeating 7-note scale, and print one of two messages.	Easy2	ImplementationString+1	No attempts yet	2s	512 MB	Judgeable
Letter CountCount how often each English letter appears in one line, ignoring case and non-letters, then print 26 rows of stars.	Easy2	StringImplementation	No attempts yet	2s	512 MB	Judgeable
PiratesGiven a lowercase word, find the letter with the highest frequency and print that letter with its count.	Easy2	StringHash map+1	No attempts yet	2s	512 MB	Judgeable
Password checkFor each of N passwords, report valid if it has a lowercase letter, uppercase letter, digit, symbol, and length at least 12, else invalid.	Easy2	StringImplementation	No attempts yet	2s	512 MB	Judgeable
Hissing MicrophoneGiven a lowercase string, check whether it contains two consecutive s characters and print hiss or no hiss.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
Life ScoreFor each name, sum the letter values (A=1 to Z=26, spaces worth 0) and print the total, or PERFECT LIFE when the total is exactly 100.	Easy2	StringImplementation	No attempts yet	2s	512 MB	Judgeable
Big number A+BRead two integers with up to 10000 digits and print their sum without leading zeros.	Easy2	StringMath+2	No attempts yet	1s	256 MB	Judgeable
Check the CheckRead dish names and price-quantity pairs until the line TOTAL, then print PAY if the waiter's total is at most the sum of price times quantity, else PROTEST.	Easy2	ImplementationString+1	No attempts yet	2s	512 MB	Judgeable
Lorem ipsumSplit a fixed Latin placeholder paragraph into words and print the words at indices L through R separated by spaces.	Easy2	StringImplementation+1	No attempts yet	0.1s	512 MB	Judgeable
Hash collision stringsPrint two length-N strings that differ but have equal Java String hashCode values, using the classic Aa/BB collision with a shared prefix.	Easy2	StringHash map+2	No attempts yet	2s	512 MB	Judgeable
Binary GamePrint the binary representations of 0 through n, concatenated with no separators.	Easy2	StringImplementation	No attempts yet	1s	256 MB	Judgeable
RickRead one line and print NO if it exactly matches one of six given phrases, otherwise print YES.	Easy2	StringImplementation	No attempts yet	1s	256 MB	Judgeable
Derivative of a polynomial functionParse a linear polynomial written like 3x+5 or -x+2 and print the constant that is its derivative.	Easy2	StringImplementation+1	No attempts yet	1s	512 MB	Judgeable
Master of the Shell GameGiven a string, perform T swaps of characters at the given 0-indexed positions in order and print the final string.	Easy2	StringSimulation+1	No attempts yet	1s	128 MB	Judgeable
What Is Your HandleSort N distinct handles by ASCII dictionary order and print the I-th one.	Easy2	SortingString+1	No attempts yet	1s	512 MB	Judgeable
Caesar CipherShift every letter of a string by k positions in the alphabet, wrapping around, and leave spaces, periods, and commas unchanged.	Easy2	StringImplementation+1	No attempts yet	1s	64 MB	Judgeable
What Does UCPC Stand For?Given one string, decide whether deleting some characters can leave exactly the subsequence UCPC, case sensitive.	Easy2	StringGreedy+1	No attempts yet	1s	512 MB	Judgeable
Occupy ParkingCount how many of the N parking spaces show 'C' in both the yesterday string and the today string.	Easy2	StringImplementation+1	No attempts yet	2s	512 MB	Judgeable
Baby BitesGiven n spoken words that are either "mumble" or a number, check if the i-th number equals i and output "makes sense" or "something is fishy".	Easy2	ImplementationString	No attempts yet	1s	512 MB	Judgeable
CPUGiven N assembly instructions for a 16-bit CPU, print the machine code for each one by packing opcode, register, and constant fields into their bit positions.	Easy2	ImplementationString	No attempts yet	1s	512 MB	Judgeable
Run-Length Encoding, Run!Encode a string as run-length pairs, or decode run-length pairs back to the original string.	Easy2	StringSimulation	No attempts yet	2s	512 MB	Judgeable
Time to DecompressRead L lines, each with a count N and a character, and print that character repeated N times on its own line.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
XORChicGiven an XOR-encrypted string whose first 8 characters decode to "CHICKENS", recover the key and output the original string.	Easy2	ImplementationBit manipulation+2	No attempts yet	1s	256 MB	Judgeable
99 Bottles of BeerGiven N, print the full lyrics of the N Bottles of Beer song, with correct singular and plural wording.	Easy2	ImplementationString+2	No attempts yet	1s	512 MB	Judgeable
Cute Number~ε٩(๑> ₃ <)۶зGiven an integer up to 10^18, check whether its digits form an arithmetic sequence with a constant difference, and print one of two fixed messages.	Easy2	ImplementationMath+2	No attempts yet	1s	512 MB	Judgeable
What's the Second Baseman's NameGiven up to 1000 player names, check whether any name equals the string anj and print one of two fixed messages.	Easy2	ImplementationString	No attempts yet	1s	512 MB	Judgeable
Bonus ScoreGiven a string of O and X for N problems, compute the total score where problem i gives i points plus a running bonus that grows on each O and resets on each X.	Easy2	ImplementationSimulation+1	No attempts yet	1s	512 MB	Judgeable
What Is a Recursive Function?Given N, print the chatbot message 'What is a recursive function?' repeated with nested quotation marks for N levels of recursion.	Easy2	ImplementationString+1	No attempts yet	1s	256 MB	Judgeable
369Count the total claps in the 369 game from 1 to N, where each number contributes one clap per digit that is 3, 6, or 9.	Easy2	ImplementationMath+2	No attempts yet	1s	512 MB	Judgeable
Mangling NamesGiven a table of pronunciation times by vowel and consonant counts, sum the times for each student name and report the total.	Easy2	ImplementationString+2	No attempts yet	2s	512 MB	Judgeable
CommandFor each of T strings, decide whether it has length 7 and its characters follow the exact pattern AABBABB with exactly two distinct letters.	Easy2	StringImplementation+1	No attempts yet	0.5s	256 MB	Judgeable
Regional Team NamesDecide whether a string splits into an institution part of 2 to 8 characters, a hyphen, then a team name of 1 to 24 characters.	Easy2	StringImplementation	No attempts yet	1s	512 MB	Judgeable
Pea Soup and PancakesRead each restaurant's name and menu, then print the first one serving both pea soup and pancakes, or a fixed fallback line if none does.	Easy2	ImplementationString+2	No attempts yet	1s	512 MB	Judgeable