Solution To Reddit Daily Programmer #207

parse_dna.rb

#!/usr/env/ruby
#Reddit Daily Programmer 207
#Includes bonus.

#Function for parsing a protein sequence.
def proteins(dna)
  #Create hash for the codons.
  codons = {"TTT"=>"Phe","TTC"=>"Phe","TTA"=>"Leu","TTG"=>"Leu","TCT"=>"Ser","TCC"=>"Ser","TCA"=>"Ser","TCG"=>"Ser","TAT"=>"Tyr","TAC"=>"Tyr","TAA"=>"STOP","TAG"=>"STOP","TGT"=>"Cys","TGC"=>"Cys","TGA"=>"STOP","TGG"=>"Trp","CTT"=>"Leu","CTC"=>"Leu","CTA"=>"Leu","CTG"=>"Leu","CCT"=>"Pro","CCC"=>"Pro","CCA"=>"Pro","CCG"=>"Pro","CAT"=>"His","CAC"=>"His","CAA"=>"Gln","CAG"=>"Gln","CGT"=>"Arg","CGC"=>"Arg","CGA"=>"Arg","CGG"=>"Arg","ATT"=>"Ile","ATC"=>"Ile","ATA"=>"Ile","ATG"=>"Met","ACT"=>"Thr","ACC"=>"Thr","ACA"=>"Thr","ACG"=>"Thr","AAT"=>"Asn","AAC"=>"Asn","AAA"=>"Lys","AAG"=>"Lys","AGT"=>"Ser","AGC"=>"Ser","AGA"=>"Arg","AGG"=>"Arg","GTT"=>"Val","GTC"=>"Val","GTA"=>"Val","GTG"=>"Val","GCT"=>"Ala","GCC"=>"Ala","GCA"=>"Ala","GCG"=>"Ala","GAT"=>"Asp","GAC"=>"Asp","GAA"=>"Glu","GAG"=>"Glu","GGT"=>"Gly","GGC"=>"Gly","GGA"=>"Gly","GGG"=>"Gly"}

  #Now loop through.
  counter = 0
  while counter < (dna.length - 2)
    codon = dna[counter] + dna[counter+1] + dna[counter+2]

    if codons[codon] == "Met"
      break
    end

    counter += 1
  end

  #Create an array to store the proteins.
  proteins = Array.new

  #Now process until we hit a STOP.
  while counter < (dna.length - 2)
    current_vals = dna[counter] + dna[counter+1] + dna[counter+2]
    current_prot = codons[current_vals]
    proteins.push(current_prot)
    end

    counter += 1
  end

  #Create an array to store the proteins.
  proteins = Array.new

  #Now process until we hit a STOP.
  while counter < (dna.length - 2)
    current_vals = dna[counter] + dna[counter+1] + dna[counter+2]
    current_prot = codons[current_vals]
    proteins.push(current_prot)

    #Increment the counter.
    counter += 3

    #Break if we hit a stop.
    if current_prot == "STOP"
      break
    end
  end

  #Print it.
  puts proteins.join("-")
end

#Main code begins here with the input sequence.
sequence = "A T G T T T C G A G G C T A A"
sequence_arr = sequence.split(" ")
result = ""
    #Break if we hit a stop.
    if current_prot == "STOP"
      break
    end
  end

  #Print it.
  puts proteins.join("-")
end

sequence = "A T G T T T C G A G G C T A A"
sequence_arr = sequence.split(" ")
result = ""
counter = 0

#Loop through the sequence values.
sequence_arr.each do |item|
  #Add a space if we're not at the first instance.
  if counter != 0
    result += " "
  end

  #Figure out the corresponding value.
  if item == "A"
    result += "T"
  elsif item == "T"
    result += "A"
  elsif item == "G"
    result += "C"
  else
    result += "G"
  end

  counter += 1
end

#Print the final results.
puts "#{sequence}"
proteins(sequence_arr)
puts "#{result}"