Solution To Reddit Daily Programmer #207 - Generating DNA Sequences

generate-dna.ps1

<#
	DNA Sequence - Daily Programmer #207
	http://www.reddit.com/r/dailyprogrammer/comments/2zyipu/20150323_challenge_207_easy_bioinformatics_1_dna/
#>

#Main input.
$inputSequence = "A A T G C C T A T G G C"

#Hash defining the pairs.
$pairs = @{'A'='T';'T'='A';'G'='C';'C'='G'}

#Create a variable to store the results.
$result = ""

#Check for the item as a key.
$length = $inputSequence.Length

#Loop through each item.
for($i = 0; $i -lt $length; $i++)
{
	#Get the current value and cast it as a string.
	$current = $inputSequence[$i]
	$current = [string]$current
	
	#Check if the value is a space or not and append accordingly to results.
	if($pairs.ContainsKey($current))
	{
		$result += $pairs[$current]
	}
	else
	{
		$result += " "
	}
}

#Run through the final output.
Write-Host "Original sequence: $inputSequence"
Write-Host "Pairing sequence: $result"