A little bit of kata in my life
Given a 2D array and a number of generations, compute n timesteps of Conway’s Game of Life.
The rules of the game are:
Each cell’s neighborhood is the 8 cells immediately around it (i.e. Moore Neighborhood). The universe is infinite in both the x and y dimensions and all cells are initially dead - except for those specified in the arguments. The return value should be a 2d array cropped around all of the living cells. (If there are no living cells, then return [[]].)
For illustration purposes, 0 and 1 will be represented as ░░ and ▓▓ blocks respectively (PHP, C: plain black and white squares). You can take advantage of the htmlize function to get a text representation of the universe, e.g.:
print(htmlize(cells))
In this example you have to validate if a user input string is alphanumeric. The given string is not nil/null/NULL/None, so you don’t have to check that.
The string has the following conditions to be alphanumeric:
"" is not valid)0 to 9Create a function that transforms any positive number to a string representing the number in words. The function should work for all numbers between 0 and 999999.
number2words(0) ==> "zero"number2words(1) ==> "one"number2words(9) ==> "nine"number2words(10) ==> "ten"number2words(17) ==> "seventeen"number2words(20) ==> "twenty"number2words(21) ==> "twenty-one"number2words(45) ==> "forty-five"number2words(80) ==> "eightys"number2words(99) ==> "ninety-nine"number2words(100) ==> "one hundred"number2words(301) ==> "three hundred one"number2words(799) ==> "seven hundred ninety-nine"number2words(800) ==> "eight hundred"number2words(950) ==> "nine hundred fifty"number2words(1000) ==> "one thousand"number2words(1002) ==> "one thousand two"number2words(3051) ==> "three thousand fifty-one"number2words(7200) ==> "seven thousand two hundred"number2words(7219) ==> "seven thousand two hundred nineteen"number2words(8330) ==> "eight thousand three hundred thirty"number2words(99999) ==> "ninety-nine thousand nine hundred ninety-nine"number2words(888888) ==> "eight hundred eighty-eight thousand eight hundred eighty-eight"
You are to write a Regular Expression that matches any string with at least one number divisible by 4 (with no remainder). In most languages, you could do this easily by using number % 4 == 0. How would you do it with Regex?
A number will start with [ and end with ]. They may (or may not) include a plus or minus symbol at the start; this should be taken into account. Leading zeros may be present, and should be ignored (no octals here ;P). There may be other text in the string, outside of the number; this should also be ignored. Also, all numbers will be integers; any floats should be ignored.
If there are no valid numbers defined as above, there should be no match made by your regex.
So here are some examples:
"[+05620]" // 5620 is divisible by 4 (valid)"[+05621]" // 5621 is not divisible by 4 (invalid)"[-55622]" // -55622 is not divisible by 4 (invalid)"[005623]" // 5623 invalid"[005624]" // 5624 valid"[-05628]" // valid"[005632]" // valid"[555636]" // valid"[+05640]" // valid"[005600]" // valid"the beginning [0] ... [invalid] numb[3]rs ... the end" // 0 is valid"No, [2014] isn't a multiple of 4..." // 2014 is invalid"...may be [+002016] will be." // 2016 is valid
You probably know the “like” system from Facebook and other pages. People can “like” blog posts, pictures or other items. We want to create the text that should be displayed next to such an item.
Implement a function likes :: [String] -> String, which must take in input array, containing the names of people who like an item. It must return the display text as shown in the examples:
likes([]) # must be "no one likes this"likes(["Peter"]) # must be "Peter likes this"likes(["Jacob", "Alex"]) # must be "Jacob and Alex like this"likes(["Max", "John", "Mark"]) # must be "Max, John and Mark like this"likes(["Alex", "Jacob", "Mark", "Max"]) # must be "Alex, Jacob and 2 others like this"
For 4 or more names, the number in and 2 others simply increases.
If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.
Finish the solution so that it returns the sum of all the multiples of 3 or 5 below the number passed in.
Note: If the number is a multiple of both 3 and 5, only count it once. Also, if a number is negative, return 0(for languages that do have them)
Courtesy of projecteuler.net
Welcome. In this kata, you are asked to square every digit of a number and concatenate them.
For example, if we run 9119 through the function, 811181 will come out, because 92 is 81 and 12 is 1.
Note: The function accepts an integer and returns an integer
A Narcissistic Number is a positive number which is the sum of its own digits, each raised to the power of the number of digits in a given base. In this Kata, we will restrict ourselves to decimal (base 10).
For example, take 153 (3 digits), which is narcisstic:
1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153
and 1652 (4 digits), which isn’t:
1^4 + 6^4 + 5^4 + 2^4 = 1 + 1296 + 625 + 16 = 1938
The Challenge:
Your code must return true or false depending upon whether the given number is a Narcissistic number in base 10.
Error checking for text strings or other invalid inputs is not required, only valid positive non-zero integers will be passed into the function.
Write a function that accepts an array of 10 integers (between 0 and 9), that returns a string of those numbers in the form of a phone number.
create_phone_number([1, 2, 3, 4, 5, 6, 7, 8, 9, 0]) # => returns "(123) 456-7890"
The returned format must be correct in order to complete this challenge.
Don’t forget the space after the closing parentheses!
Define a function that takes one integer argument and returns logical value true or false depending on if the integer is a prime.
Per Wikipedia, a prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.
0).n, or n/2, will be too slow.Write a function named first_non_repeating_letter that takes a string input, and returns the first character that is not repeated anywhere in the string.
For example, if given the input 'stress', the function should return 't', since the letter t only occurs once in the string, and occurs first in the string.
As an added challenge, upper- and lowercase letters are considered the same character, but the function should return the correct case for the initial letter. For example, the input 'sTreSS' should return 'T'.
If a string contains all repeating characters, it should return an empty string ("") or None — see sample tests.
The Fibonacci numbers are the numbers in the following integer sequence (Fn):
“0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, …”
such as
“F(n) = F(n-1) + F(n-2) with F(0) = 0 and F(1) = 1.”
Given a number, say prod (for product), we search two Fibonacci numbers F(n) and F(n+1) verifying
“F(n) * F(n+1) = prod.”
Your function productFib takes an integer (prod) and returns an array:
[F(n), F(n+1), true] or {F(n), F(n+1), 1} or (F(n), F(n+1), True)
depending on the language if F(n) * F(n+1) = prod.
If you don’t find two consecutive F(m) verifying F(m) * F(m+1) = prod you will return
[F(m), F(m+1), false] or {F(n), F(n+1), 0} or (F(n), F(n+1), False)
F(m) being the smallest one such as F(m) * F(m+1) > prod.
(depend on the language)
productFib(714) # should return (21, 34, true),# since F(8) = 21, F(9) = 34 and 714 = 21 * 34productFib(800) # should return (34, 55, false),# since F(8) = 21, F(9) = 34, F(10) = 55 and 21 * 34 < 800 < 34 * 55-----productFib(714) # should return [21, 34, true],productFib(800) # should return [34, 55, false],-----productFib(714) # should return {21, 34, 1},productFib(800) # should return {34, 55, 0},-----productFib(714) # should return {21, 34, true},productFib(800) # should return {34, 55, false},
Note:
You can see examples for your language in “Sample Tests”.
Your task in the kata is to determine how many boats are sunk damaged and untouched from a set amount of attacks. You will need to create a function that takes two arguments, the playing board and the attacks.
The board
Boats are placed either horizontally, vertically or diagonally on the board. 0 represents a space not occupied by a boat. Digits 1-3 represent boats which vary in length 1-4 spaces long. There will always be at least 1 boat up to a maximum of 3 in any one game. Boat sizes and board dimentions will vary from game to game.
Attacks
Attacks are calculated from the bottom left, first the X coordinate then the Y. There will be at least one attack per game, and the array will not contain duplicates.
[[2, 1], [1, 3], [4, 2]]
First attack [2, 1] = 3
Second attack [1, 3] = 0
Third attack [4, 2] = 1
Function Initialization
board = [[0,0,0,2,2,0],[0,3,0,0,0,0],[0,3,0,1,0,0],[0,3,0,1,0,0]]attacks = [[2, 1], [1, 3], [4, 2]]damaged_or_sunk(board, attacks)
Scoring
1 point for every whole boat sank.
0.5 points for each boat hit at least once (not including boats that are sunk).
-1 point for each whole boat that was not hit at least once.
Sunk or Damagedsunk = all boats that are sunkdamaged = all boats that have been hit at least once but not sunknotTouched/not_touched = all boats that have not been hit at least once
Output
You should return a hash with the following data
'sunk', 'damaged', 'not_touched', 'points'
In our above example..
First attack: boat 3 was damaged, which increases the points by 0.5
Second attack: miss nothing happens
Third attack: boat 1 was damaged, which increases the points by 0.5boat 2 was untouched so points -1 and notTouched +1 in Javascript/Java/C# and not_touched +1 in Python/Ruby.
No whole boats sank
Return Hash
{ 'sunk': 0, 'damaged': 2 , 'not_touched': 1, 'points': 0 }
Your task is to sort a given string. Each word in the string will contain a single number. This number is the position the word should have in the result.
Note: Numbers can be from 1 to 9. So 1 will be the first word (not 0).
If the input string is empty, return an empty string. The words in the input String will only contain valid consecutive numbers.
"is2 Thi1s T4est 3a" --> "Thi1s is2 3a T4est""4of Fo1r pe6ople g3ood th5e the2" --> "Fo1r the2 g3ood 4of th5e pe6ople""" --> ""
You need to write regex that will validate a password to make sure it meets the following criteria:
Valid passwords will only be alphanumeric characters.
Write an algorithm that takes an array and moves all of the zeros to the end, preserving the order of the other elements.
move_zeros([1, 0, 1, 2, 0, 1, 3]) # returns [1, 1, 2, 1, 3, 0, 0]
Pyramids are amazing! Both in architectural and mathematical sense. If you have a computer, you can mess with pyramids even if you are not in Egypt at the time. For example, let’s consider the following problem. Imagine that you have a pyramid built of numbers, like this one here:
/3/\7\ 42 \4\ 68 5 \9\ 3
Let’s say that the ‘slide down’ is the maximum sum of consecutive numbers from the top to the bottom of the pyramid. As you can see, the longest ‘slide down’ is 3 + 7 + 4 + 9 = 23
Your task is to write a function longestSlideDown (in ruby/crystal/julia: longest_slide_down) that takes a pyramid representation as argument and returns its’ largest ‘slide down’. For example,
longestSlideDown([[3], [7, 4], [2, 4, 6], [8, 5, 9, 3]]) => 23
My tests include some extraordinarily high pyramids so as you can guess, brute-force method is a bad idea unless you have a few centuries to waste. You must come up with something more clever than that.
(c) This task is a lyrical version of the Problem 18 and/or Problem 67 on ProjectEuler.
Attention Agent.
The White House is currently developing a mobile app that it can use to issue instructions to its undercover agents.
Part of the functionality of this app is to have messages that can be read only once, and are then destroyed.
As our best undercover developer, we need you to implement a SecureList class that will deliver this functionality.
Behaviour different to the traditional list is outlined below:
messages=SecureList([1,2,3,4])print messages # prints [1,2,3,4]print messages # prints []
messages=SecureList([1,2,3,4])print "my messages are: %r."%messages # prints "my messages are: [1,2,3,4].print messages # prints []
To complete this kata you need to be able to define a class that implements __getitem__(), __str__(), __repr__(), and possibly __len__().
The maximum sum subarray problem consists in finding the maximum sum of a contiguous subsequence in an array or list of integers:
max_sequence([-2, 1, -3, 4, -1, 2, 1, -5, 4])# should be 6: [4, -1, 2, 1]
Easy case is when the list is made up of only positive numbers and the maximum sum is the sum of the whole array. If the list is made up of only negative numbers, return 0 instead.
Empty list is considered to have zero greatest sum. Note that the empty list or array is also a valid sublist/subarray.
Create a class called Warrior which calculates and keeps track of their level and skills, and ranks them as the warrior they’ve proven to be.
"Pushover" and can progress all the way to "Greatest"."Pushover", "Novice", "Fighter", "Warrior", "Veteran", "Sage", "Elite", "Conqueror", "Champion", "Master", "Greatest"."Pushover" tier, levels 80-89 fall within "Champion" tier, etc.)"Greatest"."Invalid level".20 * diff * diff where diff equals the difference in levels between the enemy and your warrior."Easy fight", "A good fight", "An intense fight". Return "Easy fight" if your warrior is 2 or more levels higher than your enemy’s level. Return "A good fight" if your warrior is either 1 level higher or equal to your enemy’s level. Return "An intense fight" if your warrior’s level is lower than the enemy’s level."You've been defeated". (Remember, difference in rank & enemy level being 5 levels higher or more must be established for this.)"Not strong enough", without any archiving of the result.
bruce_lee = Warrior()bruce_lee.level # => 1bruce_lee.experience # => 100bruce_lee.rank # => "Pushover"bruce_lee.achievements # => []bruce_lee.training(["Defeated Chuck Norris", 9000, 1]) # => "Defeated Chuck Norris"bruce_lee.experience # => 9100bruce_lee.level # => 91bruce_lee.rank # => "Master"bruce_lee.battle(90) # => "A good fight"bruce_lee.experience # => 9105bruce_lee.achievements # => ["Defeated Chuck Norris"]
Write a function deNico/de_nico() that accepts two parameters:
key/$key - string consists of unique letters and digitsmessage/$message - string with encoded messageand decodes the message using the key.
First create a numeric key basing on the provided key by assigning each letter position in which it is located after setting the letters from key in an alphabetical order.
For example, for the key crazy we will get 23154 because of acryz (sorted letters from the key).
Let’s decode cseerntiofarmit on using our crazy key.
1 2 3 4 5---------c s e e rn t i o fa r m i to nAfter using the key:
2 3 1 5 4---------s e c r et i n f or m a t io n
message is never shorter than the key.
deNico("crazy", "cseerntiofarmit on ") => "secretinformation"deNico("abc", "abcd") => "abcd"deNico("ba", "2143658709") => "1234567890"deNico("key", "eky") => "key"
Check the test cases for more examples.
Sort these integers for me …
By name …
Do it now !
Range is 0-999
There may be duplicates
The array may be empty
Create a RomanNumerals class that can convert a roman numeral to and from an integer value. It should follow the API demonstrated in the examples below. Multiple roman numeral values will be tested for each helper method.
Modern Roman numerals are written by expressing each digit separately starting with the left most digit and skipping any digit with a value of zero. In Roman numerals 1990 is rendered: 1000=M, 900=CM, 90=XC; resulting in MCMXC. 2008 is written as 2000=MM, 8=VIII; or MMVIII. 1666 uses each Roman symbol in descending order: MDCLXVI.
RomanNumerals.to_roman(1000) # should return 'M'RomanNumerals.from_roman('M') # should return 1000