Niall47

=begin
  Run length encodingRun-length encoding (RLE) is a simple form of data compression, where runs (consecutive data elements) are replaced by just one data value and count.
  For example we can represent the original 53 characters with only 13.
  "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWB" -> "12WB12W3B24WB"
  RLE allows the original data to be perfectly reconstructed from the compressed data, which makes it a lossless data compression."AABCCCDEEEE" -> "2AB3CD4E" -> "AABCCCDEEEE"
  For simplicity, you can assume that the unencoded string will only contain the letters A through Z (either lower or upper case) and whitespace.
  This way data to be encoded will never contain any numbers and numbers inside data to be decoded always represent the count for the following character.
=end

# Usage example

Niall47

=begin
Luhn check
The Luhn check is a simple checksum, famously used to check credit card numbers are at least possibly valid.
Take this number:
4539 3195 0343 6467
The first thing we do is, starting on the right, double every second number and, if that number is greater than 9, subtract 9 from it:
4539319503436467
^ ^ ^ ^ ^ ^ ^ ^
8569 6195 0383 3437
The next step is to add all the digits:

Niall47

=begin
Atbash cipher
The Atbash cipher is a type of ancient encryption created to encode messages in Hebrew.

At its heart is a very simple substitution cipher that transposes all the letters in the alphabet backwards. The first letter in the alphabet is replaced by the the last letter so A -> Z, B -> Y etc.

Plain:  abcdefghijklmnopqrstuvwxyz
Cipher: zyxwvutsrqponmlkjihgfedcba
It is obviously a very weak encryption mechanism!

Niall47

string1 = 'GAGCCTACTAACGGGAT'.chars
string2 = 'CATCGTAATGACGGCCT'.chars
diff = 0
string1.each_with_index do |character, index|
	if character != string2[index]
		diff +=1
	end
end
puts diff

Niall47

resistor_colours = ['black', 'brown', 'red', 'orange', 'yellow', 'green', 'blue', 'violet', 'grey', 'white']
input_array = gets.chomp.gsub(' ', '').split('-')
puts resistor_colours.find_index(input_array[0]).to_s + resistor_colours.find_index(input_array[1]).to_s

Niall47

input = gets
		.chomp
		.upcase
		.gsub(/[^A-Z]/i, '')
		.chars
puts "isogram" if input == input.uniq

Niall47

scores = {
  /[AEIOULNRST]/ => 1,
  /[DG]/ => 2,
  /[BCMP]/ => 3,
  /[FHVWY]/ => 4,
  /[K]/ => 5,
  /[JX]/ => 8,
  /[QZ]/ => 10
}

Niall47

Feature: I look through emails
  Scenario: I look through emails
    Given I check the email has been recieved
    And I search for an email with a "subject" of "Notification of application"
    Then I delete all emails from my inbox
    And I check the email has been recieved