function K = kmer_gapped_kernel(S,k,maxgaps,lambda)
%function K = kmer_gapped_kernel(S,k,maxgaps,lambda)
%
% Computes the k-mer gapped kernel between the strings stored in S;
% w gaps are allowed. The features are weighted by an
% exponential lambda^-m, where m is the actual number of gaps for
% that feature.
%
%INPUTS
% S = a cell array containing all strings
% k = an integer indicating the size of the k-mer v(not including the gaps)
% maxgaps = an integer