pythagorean_triplet

triplet.rb

require 'pry'

class Triplet
  attr_reader :a, :b, :c

  def initialize(a, b, c)
    @a = a
    @b = b
    @c = c
  end

  def self.where(args)
    max_factor_given(args)
  end

  def sum
    a + b + c
  end

  def product
    a * b * c
  end

  def pythagorean?
    a**2 + b**2 == c**2
  end

  private

  def self.max_factor_given(args)
    triplets = []
    args[:min_factor] ? min_c = args[:min_factor] + 2 : min_c = 3
    args[:max_factor].downto(min_c) do |c|
      b = c - 1
      while b**2 > c**2 / 2 do
        a = Math.sqrt(c**2 - b**2).to_i
        if min_factor_given?(args)
          triplets << Triplet.new(a, b, c) if Triplet.new(a, b, c).pythagorean? && a >= args[:min_factor]
        elsif sum_given?(args)
          triplets << Triplet.new(a, b, c) if Triplet.new(a, b, c).pythagorean? && Triplet.new(a, b, c).sum == args[:sum]
        else
          triplets << Triplet.new(a, b, c) if Triplet.new(a, b, c).pythagorean? 
        end
        b -= 1
      end
      b = c - 1
    end
    triplets
  end

  def self.min_factor_given?(args)
    args.has_key?(:min_factor)
  end

  def self.sum_given?(args)
    args.has_key?(:sum)
  end
end