cic

string sequence = "TCGGTACACGGTATGAGCAGGCGCCTCGTGAGACCATTACGTATACCAGGTGTCCTGTAAGCAGCGAAGGCCCATACGCGAGATACACTGCCAGAAAACCGCGTGTCTACGAGTCGTGGTAAATTTAATCTGGCTGAGGTGTAGACATTCCAGGCGGTGCGTCTGCTGTCGGGTCCCTCTGGTGACTGGCTAGATGGACTTGCCGTTGGAAGACACAGCATGACCCCGCCTCTCTATTGATGTCACGGCG";

            int countA = 0;
            int countC = 0;
            int countG = 0;
            int countT = 0;

            char A = 'A';
            char C = 'C';
            char G = 'G';
            char T = 'T';

            foreach (char _base in sequence)
            {
                if (_base == A)
                {
                    countA++;
                }
                else if (_base == C)
                {
                    countC++;
                }
                else if (_base == G)
                {
                    countG++;
                }
                else
                {
                    countT++;
                }
            }

            Console.WriteLine("A: " + countA + ", C: " + countC + ", G: " + countG + ", T: " + countT);