program.rb

# frozen_string_literal: true

require 'set'

# User class
class User
  def initialize(uid)
    @id = uid
    @associates = []
  end

  attr_reader :id
  attr_reader :associates

  def add_assoc(user)
    @associates.push(user)
  end
end

def bfs_iter(user_hash, vertex)
  frontier = []
  visited = Set[]
  frontier.push(vertex)
  until frontier.empty?
    vertex = frontier.slice!(0)
    next if visited.include?(vertex)

    visited.add(vertex)
    user_hash[vertex].each do |u|
      frontier.push(u)
    end
  end
  return visited
end

def build_assoc(edges)
  user_array = []
  user_set = Set[]
  user_hash = {}
  # figure out how many memebrs we have
  edges.each do |edge|
    edge.each do |member|
      user_set.add(member)
    end
  end
  user_set.each do |uid|
    uuid = User.new(uid)
    user_array.push(uuid)
  end
  edges.each do |assoc|
    user_array[assoc[0] - 1].add_assoc(assoc[1])
    user_array[assoc[1] - 1].add_assoc(assoc[0])
  end
  # build hash?
  user_array.each do |user|
    user_hash[user.id] = user.associates
  end

  puts bfs_iter(user_hash, 1)


  # # my reference
  # user_hash.each do |uid, assocs|
  #   # do w/e
  # end

end

nverts = nil
nedges = nil
edges = []
STDIN.each do |line|
  line = line
  if nverts.nil?
    nverts = line.chomp.to_i
  elsif nedges.nil?
    nedges = line.chomp.to_i
    next
  end

  unless nverts.nil? || nedges.nil?
    # grab edges
    edges.push(line.split(' ').map(&:to_i))
    # clear vars
  end

  next if edges.length != nedges

  # function call
  build_assoc(edges)

  # clear vars
  edges.clear
  nverts = nil
  nedges = nil
end