List of Ruby Kata to Update

Ruby 3.0 was added. This page lists the kata requiring manual updates.

Overview

From Ruby 3.0, we'll be using RSpec under the hood instead of a custom test framework. Tests should be compatible as long as the structure matches describe -> it -> assertion. Assertion methods from the old test framework is still available to help with migration, but it should not be used for new tests.

/home/codewarrior/solution.txt no longer exists, use /workspace/solution.txt, which is the standard location for all languages and versions (also exists in older language versions).

Test.describe and Test.it are no longer supported.

To Update

To avoid enabling Ruby 3.0 for a kata with some edge cases, the structure of the test was checked before running it with Ruby 3.0. This section lists both kata with unsupported test structure or failing with Ruby 3.0.

Examples:

describe -> assertion is invalid:

describe "Group" do
  Test.assert_equals(add(1, 1), 2)
end

it without describe is invalid:

it "test case" do
  Test.assert_equals(add(1, 1), 2)
end

Top level assertion is invalid:

Test.assert_equals(add(1, 1), 2)

Useless test group/case like the following should be removed:

describe "Not a test group" do
  puts "some fancy output"
end

Unfortunately, there are many from myjinxin. Also, remove/minimize any logs in test cases.

Assertions can be updated to use RSpec matchers at the same time, but fixing the test structure to make it Ruby 3.0 compatible should be prioritized.

Use the new "Fork" feature to update:

You should see "Fork" when viewing a kata with the language you've completed in selected. Click that to open a translation editor with the current version filled in. The proposed changes can be merged or rejected after publishing, just like translations.

List of Kata

NOTE: If you find a repeating pattern that can be fixed using a Ruby script, let me know.

These are grouped by the translator unless the translator only did one.

GiacomoSorbi

1. 2 Arrays 1 Sort
2. 80's Kids #1: How Many Licks Does it Take?
3. 80's Kids #3: Punky Brewster's Socks
4. 80's Kids #4: Legends of the Hidden Temple
5. 80's Kids #7: She's a Small Wonder
6. A Needle in the Haystack
7. AD2070: Help Lorimar troubleshoot his robots- ultrasonic distance analysis
8. Acronym Buster
9. Adding Binary Numbers
10. Airport Arrivals/Departures - #1
11. Algorithmic predicament- Bug Fixing #9
12. Alphabet war - airstrike - letters massacre
13. Alphabet war
14. Alphabetized
15. Always perfect
16. Are they square 2?
17. Array Info
18. Arrays and hex color codes
19. BBQ Pitmaster
20. Balanced Number (Special Numbers Series #1 )
21. Band name generator
22. Barking mad
23. Base Conversion
24. Basic DeNico
25. Basic Sequence Practice
26. Batman Quotes
27. Breadcrumb Generator
28. Caesar Cipher Helper
29. Calculating Expected Utility
30. Cambridge Word Scramble
31. Chuck Norris III - Cage Match
32. Class conundrum - Bug Fixing #7
33. Computing the complex logarithm function
34. Convert between radians and degrees
35. Correct the date-string
36. Custom Christmas Tree
37. Cycle Detection: greedy algorithm
38. D&D Character generator #3: carrying capacity
39. Decibel Scale
40. Decimal to any Rational or Irrational Base Converter
41. Delete occurrences of an element if it occurs more than n times
42. Difference between biggest 2 numbers
43. Déjà vu Duplicates
44. EAN Validation
45. Elementary Arithmetic - Carries Count
46. Elo rating - one game, one pair
47. Explosive Sum
48. Extra Perfect Numbers (Special Numbers Series #7)
49. Factorial tail
50. Feed Kahumolings!
51. Fibonacci, Tribonacci and friends
52. Find heavy ball - level: conqueror
53. Find heavy ball - level: master
54. Find heavy ball - level: novice
55. Finish Guess the Number Game
56. Geometric Mean I
57. Geometric Mean II
58. Get the Excel column title!
59. Grasshopper - Bug Squashing
60. Group Repeating Fractions
61. HTML Complementary Color
62. Hamming Numbers
63. Hamster me
64. Histogram - H1
65. Job Matching #1
66. Josephus Permutation
67. Josephus Survivor
68. Jumble words
69. Jumping Number (Special Numbers Series #4)
70. LOTTO 6 aus 49 - 6 of 49
71. Last digit of a large number
72. Make a spiral
73. Map function issue
74. Max number of people and year in a specific place
75. Maximum Gap (Array Series #4)
76. Maximum Multiple
77. Maximum Triplet Sum (Array Series #7)
78. Morse Encoding
79. Most improved - Puzzles #4
80. Multiply Two Numbers Without Integers
81. Name on billboard
82. Ninja vs Samurai: Attack + Block
83. No Modulo Mk II
84. Number , number ... wait LETTER !
85. Number encrypting: decypher
86. One Variable Second Degree Equation Solver
87. Parse the log
88. Permutations Of An Array And Associated Values
89. Prefill an Array
90. Prime number decompositions
91. Ratio of Bouncy Numbers
92. RegExp Fun #1 - When I miss few days of gym
93. Regex Password Validation
94. Remember
95. Remove HTML tags using regexp
96. Return 1, 2, 3 randomly
97. Sequence classifier
98. Shop Inventory Manager
99. Simple Events
100. Simple fraction to mixed number converter
101. Sweet Dreams are Made of Cheese
102. Text align justify
103. There are two kinds of people
104. Tom's Allergies
105. Transpose of a Matrix
106. UN-usual Sort
107. Width-Height Ratio
108. validDate Regex
109. validate code with simple regex
110. zero-balanced Array

anter69

1. Calculate Derivative #1 - Single Integer Equation
2. Consecutive Count
3. Find the Integral
4. Iterative Rotation Cipher
5. Square sums (simple)
6. String -> N iterations -> String
7. Strong password?
8. Unary Messages

g964

1. Backwards Read Primes
2. Disguised sequences (II)
3. Double Cola
4. First Variation on Caesar Cipher
5. Floating-point Approximation (III)
6. Growth of a Population
7. I love big nums and I cannot lie
8. Is my friend cheating?
9. Looking for a benefactor
10. Meeting
11. Primes in numbers
12. What's a Perfect Power anyway?
13. Which are in?

myjinxin2015

1. Simple Fun #128: Doubly Not Less
2. Simple Fun #51: Array Previous Less
3. Simple Fun #56: Beautiful Text

jhoffner

1. ASCII85 Encoding & Decoding
2. Codewars style ranking system
3. Linked Lists - Get Nth Node
4. Nesting Structure Comparison
5. Ruby Array invoke instance method
6. Simple Interactive Interpreter
7. Simpler Interactive Interpreter
8. Temperature converter
9. The builder of things
10. Typer.js

raulbc777

Can be updated by s/it .+\n\s+(.+)\s+end/\1/

Removes it when there's a single line in between. Some tests have more than one line inside a nested it.

1. #10 Matrices: Creating Hankel Matrices
2. Approximate Fractions
3. Are you Geometric or Arithmetic? No, I´m both of them.
4. Avoid trillion years of calculations !!
5. Building Chains Using the Arithmetic Derivative of a Number
6. Composed Integers Having Prime Factors Only Once
7. Equivalent Dice
8. Generate Numbers From Digits #2
9. Identifying Top Users and their Corresponding Purchases On a Website
10. Non Decomposable Primes as Sums of Perfect Squares
11. Possible Triangles Formed with Available Iron Rods
12. Primes with Even Digits
13. Rearrangement of Numbers to Have The Minimum Divisible by a Given Factor
14. Required Data I
15. Simultaneous Equations - Three Variables
16. Sorting Arrays by the Amount of Perfect Squares that Each Element May Generate
17. The Primes as a Result of the Longest Consecutive Sum I (https://www.codewars.com/kata/57aaaada72292d3b8f0001b4/ruby)
18. Tracking Hits for Different Sum Values for Different Kinds of Dice
19. Working With Coloured Numbers II
20. Working With Coloured Numbers

adrian.eyre

1. Adding words - Part II
2. Connect 4
3. Guess Who?
4. Guess the Word: Count Matching Letters
5. Mastermind
6. Pigs in a Pen
7. Street Fighter 2 - Character Selection - Part 2
8. Sum of all the multiples of 3 or 5
9. Vending Machine

nbeck

1. Divide and Conquer

NaMe613

1. Building blocks
2. Consecutive Digit Constraints
3. Fractions of a currency' smallest value
4. Last man standing
5. Recursive Floor Sequence
6. Routes in a square grid
7. Sequence generator
8. Special Multiples
9. Using the Codewars API - Kata Rank
10. Zip it!

bellmyer

1. Football Fever!
2. Loop Through Conway's Game of Life
3. Make Ruby Hashes Act Like JavaScript Objects
4. Solve the Mysteries of Christianity

Blind4Basics

1. Alphametics Solver
2. Battleship field validator II
3. Battleship field validator
4. Bird Mountain
5. Blaine is a pain
6. Break the pieces (Evilized Edition)
7. Cut the cake
8. Expression Transpiler
9. Gerrymander Solver
10. Hard Sudoku Solver
11. Hard Sudoku Solver
12. Mahjong - #1 Pure Hand
13. Path Finder #3: the Alpinist
14. Puzzle Fighter
15. Simplifying
16. Symbolic differentiation of prefix expressions
17. Transforming Maze Solver

KenKamau

1. Product-Sum Numbers
2. String array duplicates

user8436785

1. 2D Vector Mapping
2. Consecutive Ducks
3. Hexagon Beam Max Sum
4. Line Safari - Is that a line?
5. List of all Rationals
6. Schrödinger's Boolean

Firefly2002

1. ATM Heist
2. Climbing the Leaderboard
3. Connect Four
4. Dumb News: The Truth About CW Leaderboard !
5. Find the Word Pair!
6. How many are smaller than me II?
7. Memory Reallocation
8. Missing number in Unordered Arithmetic Progression
9. One Line Task: Squirrel And Tree
10. One line task: Square Every Digit
11. Prime Streaming (PG-13)

10XL

1. Argue the toss
2. Duck Duck Goose
3. Find within array
4. Generate An Array of Unique Strings
5. Scraping: Codewars Top 500 Users
6. The rarest pepe
7. Translate to 1337

Mackay

1. Calculate the function f(x) for a simple linear sequence (Easy)
2. Calculate the function f(x) for a simple linear sequence (Medium)
3. Football League Table System
4. Guess the number!
5. Roulette Bet Calculator
6. Tile Map Path Finding

user578387

1. Array#reduce
2. Binding within the List Monad
3. Function Composition
4. The 'if' function

DiegoSalazar

1. Basic HTTP Response Class
2. Basic Router With Named Segments
3. Implement Hash#safe_dig
4. Map With Empty Fallback
5. Readable N choose K
6. Split Into Arrays of Equal Size

hilary

1. 80's Kids #10: Captain Planet
2. 80's Kids #6: Rock 'Em, Sock 'Em Robots
3. 80's Kids #8: The Secret World of Alex Mack
4. 80's Kids #9: Down in Fraggle Rock
5. Create a House Cleaning Rota
6. Magic The Gathering #2: Mana

leesc22

1. Average Array
2. Back to the Future?
3. Simple Fun #332: Catch Thief
4. Simple Fun #341: Minimum Bonus
5. Simple Fun #344: Children And Apples

xDranik

1. Holiday Shopping Priority Queue

narayanswa30663

1. Arrays and Procs #1
2. Arrays and Procs #2
3. Oh dear God! Is it bugged?
4. Quadratic Enumerator

Insti

1. Every nth array element. (Advanced)
2. Food combinations
3. Reversi row rudiments
4. Testing 'Food combinations'

Voile

1. BECOME IMMORTAL
2. Faberge easter eggs crush test [linear]
3. Geohashing
4. Insane Coloured Triangles
5. Regular Expression - Check if divisible by 0b111 (7)
6. Round and Round
7. Upside-Down Numbers - Challenge Edition

moonfly

1. Deadlock Detection
2. Find The Object
3. Re-entrant Mutex (aka Counting Mutex)
4. Storing Codes
5. Wait on All Threads
6. Wait on Any Thread

nakulgupta18

1. Find the longest repeating substring
2. get character from ASCII Value

user8476848

1. We are the Robots d[(0)(0)]b

Lordnibbler

1. Change Machine
2. EventEmitter

bestwebua

1. CamelCase Method

ineiti

1. Add _ - accessors to Hash
2. Get config values of hash
3. Phone my kids
4. Return substring instance count - 2
5. Set - the card game

tachyonlabs

1. Piano Kata, Part 1
2. Twice Their Age

pawptart

1. Be Concise I - The Ternary Operator

kevinthomas

1. Exclamation marks series #13: Count the number of exclamation marks and question marks, return the product

Coder_38

1. Odds-Index

omegahm

1. Goldbach’s Conjecture
2. Santa's Secret Sorting Sequence

srMarquinho

1. Pine's Orange Tree

Beast

1. Guess the list pattern #3
2. Guess the list pattern #5
3. Guess the list pattern #6
4. Guess the string pattern #1 - Advanced

sunboshan

1. Enhenced Fixnum.times method
2. Filtering Cookie

BattleRattle

1. Only One Gift Per Child
2. SantaClausable Interface
3. Trick the Christmas Calendar!

davidhu2000

1. Fantasy Football Showdown!
2. Ruby Functions #1: Define the "Each" Function

ogryzek

1. Color Ghost
2. Find the Capitals

devtheory

1. Numbble
2. The Lamp: Revisited

JonathanHallam

1. Sudoku solver #1

obnounce

1. Unique Substring From Joined Strings

AcesOfGlory

1. Countdown - Longest Word

user8580805

1. ROT13 variant cipher

sahglie

1. ruby + accumulate

wengzilla

1. Clustering Arrays
2. Next Highest Anagram Finder

hencethus

1. First n Prime Numbers
2. Making Change: Part 2
3. Making Change
4. Name That Integer

mcclaskc

1. 1337 Classes
2. Custom attr_accessor

noku

1. Scrabble Score
2. Slices of a Series of Digits

Dr Phil

1. Angle Between Clock Hands
2. Binary Genetic Algorithms

arwengu

1. Decimals or groups of thousands??
2. [Minecraft Series #3] Lava is amazing!
3. [Minecraft Series #4] Lava is amazing, however...

nekokat

1. Alex & snooker: scores.

Glyxerine

1. Queue Battle

ReganRyanNZ

1. Hello new meta-class!
2. Meta Mad Libs

CorsaiR

1. Hangman
2. Polynomial Class

ajLapid718

1. High-Stakes Binary Blackjack

pioraid

1. Call Center Call Backs
2. Playing with cubes I

Javatlacati

1. Anchorize me!
2. Classic Hello World
3. Make them bark!

craecke

1. Integer to Musical Pitch Classes

chipit24

1. Polybius Square

SaladFork

1. Text Door Neighbors - Phone Keypad

rohitpaulk

1. Choose featured projects for Gratipay's homepage!
2. Give me my booleans, Mr. Hash!

benzrf

1. Command-line Option Parser
2. Instant Runoff Voting

mcelearr

1. Decoding a message
2. Gone fishin'
3. To buy or not to buy

GeorgeSeeger

1. Convert Symbol to Array
2. Deal a Shuffled Deck of Cards
3. Rotate Rectangles By 45 Degree Jumps

maipatana

1. From..To..Series #7: from sentence to camelCase. Can you convert it?
2. Multiplication table
3. Zero Terminated Sum

alexpop

1. Bits Battle
2. Injection
3. SHA-256 Cracker

Antiokus314

1. Abstract Model Magic
2. Chain me
3. Memoized Fibonacci

KSTNR

1. Cats in hats
2. Help Bob count letters and digits.
3. Volume of a Cuboid

Roy Gardiner

1. Represent a number in words, e.g. '1' => 'one'
2. Search for letters
3. Simple string validation

Chrono79

1. Making Copies
2. Stacked Balls - 2D
3. Stacked Balls - 3D (square base)

kkavita92

1. Code Breaker #1
2. What comes after?

phaul

1. Chess - Pawn move generator
2. Iterate function
3. Recipe DSL

Fluffy

1. Statistics Algorithm - Calculate Mean
2. Statistics Algorithm - Calculate Sample Space

prestidigitation

1. Convert a linked list to a string
2. Mutual Recursion

AJFarmar

1. Draw a Circle.
2. Pull your words together, man!

lunitik

1. Duplicate Arguments
2. Hash.flattened_keys

lokulin

1. Cartesian coordinates from degree angle
2. Valid Braces

matstc

1. Arrh, grabscrab!
2. Readability is King

vgrichina

1. Reverse linked list
2. Reverse polish notation calculator

CrowdHailer

1. Hyper Sphere
2. Palindromes Below

alessandrodalbello

1. Simple card game
2. Thinking & Testing : Incomplete string

rsalgado

1. Binary multiple of 3
2. Goldbach's Conjecture

hagi

1. Sherlock on numbers
2. Sherlock on pockets

msg7086

1. Colorful Number
2. Print a Matrix in Spiral Form

Laurynas Lazauskas

1. Keypad horror

Tavio

1. Integer division
2. Taxicab numbers

sebaas

1. Kids and candies

donaldsebleung

1. Esolang Interpreters #1 - Introduction to Esolangs and My First Interpreter (MiniStringFuck)
2. The Prediction

Tokariev Serhii

1. Shift Left
2. Vowel Recognition

JohanWiltink

1. Largest product in a series
2. Next polydivisible number

user9935269

1. Knapsack Part 1 - The Greedy Solution
2. Physics - Mechanics - Atwood Machines in Series

Unihedron

1. Completed Mahjong Hands
2. Cryptic Cave: Episode 1

pjfranzini

1. Matrix Determinant
2. Triple Trouble

BurstNova

1. Friday the 13th Part 1
2. The Greatest Warrior

ggmoy

1. Break the pieces
2. Tiny Three-Pass Compiler

tansaku

1. Evaluate mathematical expression
2. Linear Regression with One Variable

cgthornt

1. Hash With Indifferent Access
2. Roles and Permissions

hassanmir92

1. Extract Transform Load
2. Series

TheodoreDOttavio

1. Car salesmen talk too much
2. Shady Sam's Special Sweet Scented Candles

Leadboy

1. Array Condenser Step Calculator
2. Counting Digits

daveallie

1. Fat Ninjas
2. Galaxy Getaway

JoshBrodieNZ

1. Don't rely on luck.
2. Method Lockdown

binarymason

1. Brute Forcing a Password
2. Convert a Hashy String to a Hash

SnooperSnayk

1. Given an array of numbers, which are perfect squares?
2. Rubyfunge Interpreter

troglodite

1. Approximate e
2. Welcome to the City

zenAndroid

1. Arithmetic List!

ozim

1. Prepare for the Easter!
2. Power of 4

baaart

1. Arithmetic sequence - sum of n elements
2. Geometric sequence - sum of all elements

Drymonade

1. From-To-Step Sequence Generator
2. Well efficiency calculator

nyi

1. Internal Scrambler
2. Magic Sum of 3s

nza

1. Basic Math (Add or Subtract)
2. Count letters in string

dinglemouse

1. Cogs
2. Connect the Dots

fizis

1. Christmas Day
2. Simple Sentences

thatrubylove

1. A functional deck of cards....
2. Lambdas as a mechanism for Open/Closed

mariohernandezv

1. Simple transposition
2. Simple transposition class

jdonor

1. Check if binary tree is balanced
2. Find kth to last element of singly-linked list

Others

1. Pirates!! Are the Cannons ready!??
2. Palindrome chain length
3. Line Type Parser
4. The Power of Exponents
5. Orthogonal Vectors
6. Delta Bits
7. Credit Card Mask
8. The dropWhile Function
9. Count the Ones
10. Candy problem
11. Figure Out the Notes
12. 80's Kids #2: Help ALF Find His Spaceship
13. Genetic Algorithm Series - #3 Crossover
14. Array of all primes up to number N
15. Credit card issuer checking
16. Powers of 3
17. Pluralization
18. Coding Meetup #1 - Higher-Order Functions Series - Count the number of JavaScript developers coming from Europe
19. Coding Meetup #2 - Higher-Order Functions Series - Greet developers
20. Coding Meetup #4 - Higher-Order Functions Series - Find the first Python developer
21. Magic Three
22. Do you know how to make Query String?
23. STRING-ASCII_STRING??
24. Life of Possibilities
25. Strip Url Params
26. Calculate Hypotenuse of Right-angled Triangle
27. Good vs Evil
28. Who has the most money?
29. Pascal's Triangle #2
30. Dreidel dreidel
31. Adding ordinal indicator suffixes to numbers
32. Sort sentence pseudo-alphabetically
33. Atbash Cipher Helper
34. Palindrome for your Dome
35. Big to Little Endian
36. Evil Autocorrect Prank
37. What adds up
38. Bracket Duplicates
39. Wind component calculation
40. House of cards
41. Ping-Pong service problem
42. Run-length encoding
43. NATO Phonetic Alphabet Ruby
44. Triangular matrices.
45. Triangle number check
46. Enigeliisohe too Eniigeeliiisoohee Toroanisoliatooro
47. Crack the Encrypted Email
48. Next level string padding
49. Backspaces in string
50. Let's flat them out
51. Doors in the school
52. 0 to 100, real quick!
53. DotNotation Transformer
54. The Wolf of Wall Street
55. Unique Strings
56. Reversing Euclid's GCD. Parameters out of results
57. Keith Numbers
58. IBAN Validator
59. Pythagorean Triplets
60. Vonhyou's Math Class!
61. Squares in a Rectangle
62. Read a UPC/Barcode
63. Word Segmentation: MaxMatch
64. Where my anagrams at?
65. Rotate an array matrix
66. My smallest code interpreter (aka Brainf**k)
67. Greed is Good
68. Email Validation
69. Convert PascalCase string into snake_case
70. Can you get the loop ?
71. #Hashtag
72. Trip Checker
73. Tree Reconstruction
74. Blackjack Scorer
75. Integer to English
76. Cycle Detection: Floyd's The Tortoise and the The Hare
77. self_converge
78. Earliest Occurring Unique Value in Stream
79. Endianness Conversion
80. Quipu Calculator
81. Fouriest transformation
82. Most frequently used words in a text
83. Snail
84. The observed PIN
85. Sort binary tree by levels
86. Carmichael function
87. Recover a secret string from random triplets
88. Pyramid Slide Down
89. Find all possible number combos that sum to a number
90. Longest Common Subsequence (Performance version)
91. Calculator
92. Rail Fence Cipher: Encoding and Decoding
93. Knight's Attack!
94. Decode the Morse code, for real
95. Count the likes
96. Cable Matching Problem
97. Synchonizing records
98. counting in dot notation
99. Count IPv6 Addresses (ruby only)
100. Create a linked list class and its methods
101. German Unicode Characters to ASCII Equivalents
102. Date Range Formatter
103. Texas Hold'em Poker
104. Reverse word order in place.
105. Best GF (Guardian Force) junctions based on compatibility
106. Playfair cipher
107. Palindromes
108. Word proposals
109. Square Root Games
110. Mahjong II: Is this complex set a winning set?
111. Dependency check
112. Clock hands angle
113. How many dots are covered
114. Rep The Set, Gotta Rep The Power Set
115. Count the number of instances of three identical digits on a four-digit digital clock
116. Connecting Linked Lists
117. Basic variable assignment
118. Push a hash/an object into array
119. Incorrect array_remove method
120. Failed Sort - Bug Fixing #4
121. Broken Collatz
122. Not very secure
123. Gravity Flip
124. Find the max depth in an array
125. Number of Rectangles in a Grid
126. Slamming Lockers
127. Thinking & Testing : Uniq or not Uniq
128. 5 without alphanums!!!
129. Player Contact Manager
130. Hard Time Bomb
131. Feynman's square question
132. Mysterious function
133. Sum #1
134. Mr. Safety's treasures
135. XOR string reduction
136. Button sequences
137. Towers of Hanoi
138. Luck check
139. Cheating a bit...
140. A Chain adding function
141. Did I Finish my Sudoku?
142. Base64 Numeric Translator
143. Find the code and open the safe
144. Sting like a bee, float like a sponge?
145. Path Finder #4: where are you?
146. Ruby’s Eleven
147. 6 By 6 Skyscrapers
148. Haskellish Syntax
149. Guess the Passtune
150. The cross-stitch Kata
151. stripper_namer
152. Natural Language Calculator
153. Easy hacking #1
154. Triangular Peg Solitaire Solver
155. Improving hashes.
156. Grader
157. Counting sheep...
158. Are arrow functions odd?
159. Who ate the cookie?
160. Grasshopper - Messi Goals
161. Compare within margin
162. Add new item (collections are passed by reference)
163. Remove First and Last Character Part Two
164. Merging sorted integer arrays (without duplicates)
165. Thinkful - Number Drills: Blue and red marbles
166. Ensure question
167. Who is going to pay for the wall?
168. Help the Elite Squad of Brazilian forces BOPE
169. Area or Perimeter
170. Ruby Metaprogramming 101 - Dynamic Method Calls
171. No Modulo
172. Flatten
173. Power of two
174. Re-open class
175. We Have Liftoff
176. Last
177. greetings with First Name AND Last Name
178. Lazily executing a function
179. Next birth-day of the week finder
180. Find sum of top-left to bottom-right diagonals
181. sum_eq_n?
182. Center of the Matrix
183. Converting integer to currency format
184. Big Factorial
185. Do you speak retsec?
186. Russian postal code checker
187. Parsing Commandline Arguments
188. Find Duplicates
189. Counting Array Elements
190. Help the Fruit Guy
191. Is n divisible by (...)?
192. Capitals first!
193. Trigrams
194. Filter Coffee
195. Array comparator
196. Quicksum
197. Simple template
198. Translate anything into French !
199. Integer Difference
200. Sum squares of numbers in list that may contain more lists
201. Personalising Spammy Marketing Emails
202. Exclamation marks series #18: a simple slot machine that only contains exclamation marks and question marks
203. String Scramble
204. Changing letters
205. No yelling!
206. TIY-FizzBuzz
207. Return the first M multiples of N
208. Reverse the bits in an integer
209. Odder Than the Rest
210. Remove B M W
211. Alphabetically ordered
212. Knight position
213. Dropzone
214. Alphabetical Sequence
215. Bob's Treasure Map
216. Will you survive the zombie onslaught?
217. Custom each() Array method
218. Title Case
219. Bag#every?
220. Two Sum
221. Format a string of names like 'Bart, Lisa & Maggie'.
222. Array Exchange
223. Command line parameters
224. Word a10n (abbreviation)
225. Pretty date
226. Grouping and Counting
227. Flexible Card Game
228. Harshad or Niven numbers
229. Multi-tap Keypad Text Entry on an Old Mobile Phone
230. Tick Toward
231. Format Text
232. Tree Depth
233. Polynomial Evaluation - Binomial Form
234. Find the biggest piece of gold
235. Lucky Sevens
236. Parse HTML/CSS Colors
237. Markings to White Triangles and How to Find Them
238. Ka Ka Ka cypher - words only vol 1
239. Matrix Rotation
240. How many feelings?
241. The Strongest Tree in the Forest
242. Extract the domain name from a URL
243. Custom Enumerators - Fibonacci
244. Gift Unwrapping
245. Vector Class
246. Find All Array Values That Fall Within a Given Difference
247. Dynamic instance variables & attributes
248. Sum of pairs
249. Pandigital Sequence
250. Fluent Calculator
251. To BrainFuck Transpiler
252. Word statistics
253. Clock Hands
254. Tug-o'-War
255. Construct Javascript-method syntax in Ruby
256. Temp Tracker: Max, Min, Mean and Mode
257. Server: Connection Pool
258. Strings to worded numbers
259. Easter Eggs
260. Convert to ledger format
261. Cost of Shopping
262. Lat/Long Parser
263. Event Date Dilemma
264. Implement a client for an API
265. Call a block on an array multiple times
266. DIY ActiveRecord a.k.a KataRecord
267. Narcissistic Numbers
268. Robot Walk
269. Brainunpack
270. Compress string to return letter followed by numbers of times it occurs in a string
271. Stop worrying!
272. Go Shopping
273. Gammas text manipulation 1: Detecting errors using regexp
274. Non-consecutive Pairs
275. Lucky Number - Simple
276. Clear the Catacombs!
277. Morse Code (translate text to and from morse code)
278. The Black Panther Language
279. Truncate string to first n words
280. Basic Statement Coverage in Unit Testing
281. Group your pupils