Class: UlamSpiral

Inherits:
Object
  • Object
show all
Defined in:
lib/ulam_spiral.rb,
lib/ulam_spiral/version.rb

Constant Summary collapse

VERSION = 
"0.0.2"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(params = {}) ⇒ UlamSpiral

Returns a new instance of UlamSpiral.



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# File 'lib/ulam_spiral.rb', line 9

def initialize(params = {})
  @first_number = params[:first_number] || 1
  @last_number = params[:last_number] || 100
  @spiral = (0...square_length).to_a.map{ [nil] * (square_length) }
  @row = (square_length / 2.0).floor
  @column = ((square_length - 1) / 2.0).floor
  @spiral[@row][@column] = @first_number
end

Instance Attribute Details

#spiral ⇒ Object (readonly)

Returns the value of attribute spiral.



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# File 'lib/ulam_spiral.rb', line 7

def spiral
  @spiral
end

Instance Method Details

#generate_spiral ⇒ Object

generate ulam spiral



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# File 'lib/ulam_spiral.rb', line 19

def generate_spiral
  direct = 2
  ((@first_number + 1)..@last_number).each do |number|
    @row, @column = get_position(direct)
    if Prime.prime?(number)
      @spiral[@row][@column] = number if Prime.prime?(number)
    else
      @spiral[@row][@column] = ""
    end

    x, y = get_position(direct + 1)
    direct = (direct + 1) % 4 if @spiral[x][y].nil?
  end
  string_to_nil
end

#show ⇒ Object

Show on console spiral



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# File 'lib/ulam_spiral.rb', line 36

def show
  length = @last_number.to_s.length + 1
  @spiral.each do |row|
    puts "\n"
    puts row.map { |element| element.nil? ? " " * length : element.to_s.rjust(length, " ") }.join(" ")
  end
end