Exercise: DNA Sequencing

• A, C, T, G are called bases or nucleotides
• Given a sequence like "ACCGXXCXXGTTACTGGGCXTTGT" (nucleoids mixed up with other elements) return the sequences containing only ACTG orderd by length.
• The above string can be split up to ["ACCG", "C", "GTTACTGGGC", "TTGT"] and then it can be sorted to get the following:
• Expected result: ["GTTACTGGGC", "ACCG", "TTGT", "C"]