# Using arrays.
class Memofib

  def initialize
    puts "Initializing fibonacci class."
    @memo = []
  end

  def go(i)
    if i == 0 || i == 1
      return 1
    end

    if @memo[i]
      @memo[i]
    else
      @memo[i] = go(i-1) + go(i-2)
    end
  end
end
    

#but arrays are other things, too!

#A simple queue class using an array as a list.
class Queue

  def initialize
    puts "Initializing queue."
    @arr = []
  end

  def push(el)
    @arr.push(el)
    # Don't return the internal representation!
    nil
  end

  def peek()
    @arr[@arr.length - 1]
  end

  def pop()
    @arr.pop
    nil
  end
end

# Also, used as tuples.

# A point.
class Point

  def initialize(x,y)
    puts "Initializing point."
    @x = x
    @y = y
  end

  def +(p)
    #pattern matching?
    x,y = p.getXY()
    Point.new(@x + x, @y + y)
  end

  def getXY()
    [@x,@y]
  end
end

#dictionaries!

class Dictionaries
  def initialize
    @schedule1 = Hash.new
    @schedule1["Sunday"] = 0
    @schedule1["Monday"] = 0
    @schedule1["Tuesday"] = 1
    @schedule1["Wednesday"] = 0
    @schedule1["Thursday"] = 1
    @schedule1["Friday"] = 0
    @schedule1["Saturday"] = 0

    @schedule2 = {"Sunday" => 0,
                  "Monday" => 0,
                  "Tuesday" => 1,
                  "Wednesday" => 0,
                  "Thursday" => 1,
                  "Friday" => 0,
                  "Saturday" => 0}
  end

  attr_reader :schedule1, :schedule2
end