getclever.com puzzle solution

clever_solver.rb

class CleverSolver
  require 'rest-client'
  require 'json'

  def initialize
    @root = "https://DEMO_KEY:@api.getclever.com"
    @next_url = "/v1.1/students"
    @vcount = 0
  end

  def run
    while not @next_url.nil?
      puts "getting next page: #{@root + @next_url}"
      response = RestClient.get(@root + @next_url)
      json = JSON.parse(response)

      @next_url = get_next_url(json)
      
      students = json['data']
      @vcount += students.select{|s| s['data']['name']['last'].match(/^v/i)}.count
    end

    return @vcount
  end

  def get_next_url(json)
    links = json['links']
    next_url_data = links.select{|l| l['rel'] == 'next'}.first
    return next_url_data['uri'] rescue nil
  end
end

answer = CleverSolver.new.run
puts "Found #{answer} students whose last names start with 'v'."