ruby: Technical Interview

README.md

Technical Interview

Multiply
0
0
2
2
-1
-1
1
1
100000000000000000000000
100000000000000000000000
-100000000000000000000000
-100000000000000000000000
2500
-2500
-2500

Biggest
nil
1
100

Clean
[]
[[], 1, 2, 3, 4, 5, 1..5, "", "a", "b"]

Flatten
[]
[1, 2, [3, 4], 1, []]

RepeatedWords
{"hola"=>0, "tu"=>0, "esta"=>1, "es"=>1, "una"=>0, "prueba"=>1}

Palindrome
false
true
true

technical_interview.rb

module TechnicalInterview
  module Multiply
    # multiplicar 2 números sin usar en signo de multiplicar para la operación
    def self.multiply(a, b)
      return 0 if [a, b].include?(0)

      a_abs, b_abs = a.abs, b.abs
      a_positive, b_positive = a.positive?, b.positive?
      arr = a_abs > b_abs ? [a_abs] * b_abs : [b_abs] * a_abs
      result = arr.inject(&:+)

      (a_positive && b_positive) || !(a_positive || b_positive) ? result : -result
    end
  end
  module Biggest
    # búscar el número más grande de un arreglo pasando solo una vez
    def self.fetch_biggest(arr = [])
      return if arr.empty?

      arr.reduce { |acc, e| acc > e ? acc : e }
    end
  end
  module Clean
    # eliminar de un arreglo los [nil, false, 0]
    def self.clean(arr)
      arr.select { |e| ![nil, 0, false].include?(e) }
    end
  end
  module Flatten
    # aplanar arreglos en el primer nivel
    def self.flatten(arr)
      arr.reduce([]) { |acc, e| acc.concat(e) }
    end
  end
  module RepeatedWords
    # contar número de palabras repetidas
    def self.repeated_words(str = '')
      arr_str = str.downcase.tr("áéíóú", 'aeiou').gsub(/[,.\-?!]/, '').split(' ')
      arr_str.reduce({}) do |curr, e|
        curr[e] ? curr[e] += 1 : curr[e] = 0
        curr
      end
    end
  end
  module Palindrome
    def self.palindrome(str)
      str = str.gsub(/\s/, '').downcase
      str == str.reverse
    end
  end
end

puts "Multiply"
puts TechnicalInterview::Multiply.multiply(0, 1)
puts TechnicalInterview::Multiply.multiply(1, 0)
puts TechnicalInterview::Multiply.multiply(1, 2)
puts TechnicalInterview::Multiply.multiply(2, 1)
puts TechnicalInterview::Multiply.multiply(-1, 1)
puts TechnicalInterview::Multiply.multiply(1, -1)
puts TechnicalInterview::Multiply.multiply(1, 1)
puts TechnicalInterview::Multiply.multiply(-1, -1)
puts TechnicalInterview::Multiply.multiply(100000000000000000000000, 1)
puts TechnicalInterview::Multiply.multiply(1, 100000000000000000000000)
puts TechnicalInterview::Multiply.multiply(-100000000000000000000000, 1)
puts TechnicalInterview::Multiply.multiply(1, -100000000000000000000000)
puts TechnicalInterview::Multiply.multiply(50, 50)
puts TechnicalInterview::Multiply.multiply(-50, 50)
puts TechnicalInterview::Multiply.multiply(50, -50)

puts "\nBiggest"
p TechnicalInterview::Biggest.fetch_biggest([])
p TechnicalInterview::Biggest.fetch_biggest([-1, 0, 1])
p TechnicalInterview::Biggest.fetch_biggest([100, -100, 0])

puts "\nClean"
p TechnicalInterview::Clean.clean([])
p TechnicalInterview::Clean.clean([[], 0, 1, 2, 3, 4, 5, (1..5), '', 'a', 'b', nil, false])

puts "\nFlatten"
p TechnicalInterview::Flatten.flatten([])
p TechnicalInterview::Flatten.flatten([[1, 2], [[3, 4]], [1, []]])

puts "\nRepeatedWords"
p TechnicalInterview::RepeatedWords.repeated_words('Hola tú!, está es una prueba??, esta es... -prueba')

puts "\nPalindrome"
p TechnicalInterview::Palindrome.palindrome('No es un palindrome')
p TechnicalInterview::Palindrome.palindrome('Arepera')
p TechnicalInterview::Palindrome.palindrome('Do geese see God')