numbas

challenge.rb

str = "iirytroyppytpeppowuiyoiuypipiyuyotyoiwiytorouqyiepyirueuiprpptwyiroqwtuyipourrrourorwipowiorutpwtwruuioquteorioriyutwqyyprptuqqquuituyywyuoewtrppqwrtiiruirpwyptpuoyyoeyerpqiotuieripurouwuwyuwrworowitoepoypeipeypiireeorrwripuuteoitpuutturruwiyryeetyrioweytueqrrrtotrpiqetoyepoipiwrwpppiritupwipruooiepoweypiuwrqywuuwyiroqpqpruioopuiuerputpwwuuiqwpiroewrtwiqerteoyeqtutwoeoipioiuqiiiouuoqtuuwtuwiiqwppqitywuqpuutrqiyoeuuutwrwtoqrqyoeyoiporuuioiwryoeruypreprqroiyuqwtuyoytoerwqryeeripryieypiwqirtriurueypiuyuypriuiwptywppupoioyrewooytreteeriiwroietuwypieeeeeqpiiiwrirtppoeyiwpooyyporpruwuoriiyowuytiwpwpryeywotoyirqypyypoeptiuwwoyprquoetepptorwiewprpiywwtuieeiweytrrwiqtwotioryoiptyyyuriiqiyroeeiqepwteuwptpruuypipieuoiiuuweeuryuuowporrooyywyyrryriqyirooitirueruptotpryoqtipippyptiurwyiryooywtryyuurtrutwqiqiiiqwouyeooueoturuowiuwrtruwwiupwopwweoo"
key_map = %w[q w e r t y u i o p]
number_map, result = [], []

# map to keyboard character
str.split('').each do |letter|
  key_map.each_with_index do |key,index|
    number_map << index if letter == key
  end
end

# split to pairs
number_pairs = number_map.each_slice(2).to_a

# remove dupes
uniques = number_pairs - number_pairs.inject({}) {|h,v| h[v]=h[v].to_i+1; h}.reject{|k,v| v==1}.keys

# add the remaining pairs
uniques.each { |v| result << v[0] + v[1] }

# great success!
puts result.join