fabianuribe

def recursive_reverse string
  return '' if string.empty?
  string.slice!(-1) + recursive_reverse(string)
end

fabianuribe

class RPNCalculator
  def initialize
  end
 
  def evaluate(rpn)
    expressions = rpn.split(' ')
    ans = []
    expressions.each do |obj|   # example: (5 1 2 + 4 * + 3 -)
      if obj.to_s[/[0-9]+/]
        

fabianuribe

def evaluate(string, answer=[])
  return answer[0] if string.empty?

  expressions = string.split(' ')
  obj = expressions.shift 
    
  if obj.to_s[/\d+/]
    answer << obj.to_f
  else ["*","+","-","/"].include?(obj) 
    operands = answer.pop(2)

fabianuribe

# Triangle side lengths
# Write a method valid_triangle? which takes as its input three non-negative numbers. 
#It should return true if the three numbers could form the side lengths of a triangle and false otherwise.

# The arguments don't correspond to specific sides. 
# Don't worry about handling negative inputs — garbage in, garbage out.

# For example,

# valid_triangle?(0,0,0) # => false, because a triangle can't have 0-length sides

fabianuribe

#Returns a number in english language

def english_number (number)

  raise ArgumentError.new("Argument must be a positive integer") if !(number.is_a? Integer) || number < 0 

  return 'zero' if number == 0

  result = ""

fabianuribe

sudoku_string = "003020600900305001001806400008102900700000008006708200002609500800203009005010300"
sudoku_array = sudoku_string.split('')

rows_array = Array.new(9){ sudoku_array.shift(9) }

rows_array.each{|row| p row}

box_rows_array = []
# p rows_array

fabianuribe

sudoku_string = "003020600900305001001806400008102900700000008006708200002609500800203009005010300"
sudoku_array = sudoku_string.split('')

rows_array = Array.new(9){ sudoku_array.shift(9) }

rows_array.each{|row| p row}

box_rows_array = []
# p rows_array

fabianuribe

# Create an RPNCalculator class which can evaluate expressions written in Reverse Polish notation.

# It should have an evaluate instance method which takes as its input a valid RPN expression and returns its evaluation. Your calculator only needs to handle addition, multiplication, and subtraction (not division).

# Operators and numbers should be separated by a single space.

# For example,

# calc = RPNCalculator.new

fabianuribe

class Vehicle
  attr_reader :status, :wheels

  def initialize(args)
    @color = args[:color]
    @wheels = args[:wheels]
    @status = :stopped
  end

fabianuribe

require 'nokogiri'


doc = Nokogiri::HTML(File.open('post.html'))


def extract_usernames(doc)
  doc.search('.comhead > a:first-child').map do |element|
     p element.inner_text
  end