dynamicsequencelcsDNA.m

filename1 = 'cat.fasta';
filename2 = 'Dog.fasta';
lcs = longestCommonSubsequenceFromFiles(filename1, filename2);
disp(lcs);
function lcs = longestCommonSubsequenceFromFiles(filename1, filename2)
    % Read the first FASTA file
    sequences1 = fastaread(filename1);
    
    % Read the second FASTA file
    sequences2 = fastaread(filename2);
    
    % Check if each file contains at least one sequence
    if isempty(sequences1)
        error('The first file must contain at least one sequence.');
    end
    
    if isempty(sequences2)
        error('The second file must contain at least one sequence.');
    end
    
    % Get the first sequence from each file
    str1 = sequences1(1).Sequence;
    str2 = sequences2(1).Sequence;
    
    % Call the LCS function
    lcs = longestCommonSubsequence(str1, str2);
end

function lcs = longestCommonSubsequence(str1, str2)
    % Get the lengths of the input strings
    len1 = length(str1);
    len2 = length(str2);

    % Create a table to store the lengths of LCS
    table = zeros(len1+1, len2+1);

    % Compute the lengths of LCS
    for i = 1:len1
        for j = 1:len2
            if str1(i) == str2(j)
                table(i+1, j+1) = table(i, j) + 1;
            else
                table(i+1, j+1) = max(table(i+1, j), table(i, j+1));
            end
        end
    end

    % Find the LCS by backtracking the table
    lcs = '';
    i = len1;
    j = len2;
    while i > 0 && j > 0
        if str1(i) == str2(j)
            lcs = [str1(i) lcs];
            i = i - 1;
            j = j - 1;
        elseif table(i+1, j) > table(i, j+1)
            j = j - 1;
        else
            i = i - 1;
        end
    end
end