day14.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'digest'

seed='qzyelonm'
index=-1
counter=0

def check_for_key(seed, index)
        if Digest::MD5.hexdigest(seed + index.to_s).match(/(.)\1{2,}/).nil?
                return false
        else
                matchset = Digest::MD5.hexdigest(seed + index.to_s).match(/(.)\1{2,}/)[0].chr
                (index + 1).upto(index + 1000) do |idx|
                        if not Digest::MD5.hexdigest(seed + idx.to_s).match(/(#{matchset})\1{4,}/).nil?
                                return true
                        end
                end
                return false
        end
end

until counter == 64 do
        index +=1
        if check_for_key(seed, index) == true
                counter += 1
        end
end

puts index

part2.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'digest'


seed='qzyelonm'
index=-1
counter=0

def check_for_key(hashes, index)
        if hashes[index].match(/(.)\1{2,}/).nil?
                return false
        else
                matchset = hashes[index].match(/(.)\1{2,}/)[0].chr
                (index + 1).upto(index + 1000) do |idx|
                        if not hashes[idx].match(/(#{matchset})\1{4,}/).nil?
                                return true
                        end
                end
                return false
        end
end

def rehash(hash)
        1.upto(2016) do |foo|
                hash = Digest::MD5.hexdigest(hash)
        end
        return hash
end

puts "Generating hashes...."
hashes = Array.new
0.upto(50000) do |iter|
        hashes << rehash(Digest::MD5.hexdigest(seed + iter.to_s))
end


puts "Checking for keys..."
until counter == 64 do
        index +=1
        if check_for_key(hashes, index) == true
                counter += 1
        end
end

puts "Answer: #{index}"