Finding Raffle Numbers @ RubyConf2020

a.rb

# Greedy Approach with Array#product
#
# $ time ruby a.rb
# Found it! Your raffle number is f8ryt
# real	2m12.019s
# user	2m7.764s
# sys	0m3.383s

require 'digest'

def generate_hash(id, raffle_number)
  Digest::MD5.base64digest(id+ raffle_number)
end

def mine_raffle_number(id, digest)
  alphabet = %w(a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9)
  alphabet.product(alphabet, alphabet, alphabet, alphabet).each do |raffle_candidate|
    raffle_candidate = raffle_candidate.join("")
    if generate_hash(id, raffle_candidate) == digest
      puts "Found it! Your raffle number is #{raffle_candidate}"
      return
    end
  end
  puts "not found"
end

id = "https://www.crowdcast.io/seanhandley256"
digest = "VMAZY9CRQYA9JnFCbXETjg=="

mine_raffle_number(id, digest)

b.rb

# Lazy Approach with Array#permutation
#
# $ time ruby b.rb
# Found it! Your raffle number is f8ryt
# real	0m16.604s
# user	0m16.352s
# sys	0m0.129s

require 'digest'

def generate_hash(id, raffle_number)
  Digest::MD5.base64digest(id+ raffle_number)
end

def mine_raffle_number(id, digest)
  alphabet = %w(a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9)
  alphabet.permutation(5).each do |raffle_candidate|
    raffle_candidate = raffle_candidate.join("")
    if generate_hash(id, raffle_candidate) == digest
      puts "Found it! Your raffle number is #{raffle_candidate}"
      return
    end
  end
  puts "not found"
end

id = "https://www.crowdcast.io/seanhandley256"
digest = "VMAZY9CRQYA9JnFCbXETjg=="

mine_raffle_number(id, digest)

c.rb

# Benchmark just to see how long it takes to build the collection up front
#
# $ time ruby c.rb
# real	1m26.778s
# user	1m23.649s
# sys	0m2.611s

alphabet = %w(a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9)
alphabet.product(alphabet, alphabet, alphabet, alphabet)