I have another question.Since this function generates the requierd DB sequence through searching all the possible symbol combinations according to the character, arbitrary DB sequence can be obtained without regard to the limitaion of time and memory in principle. However, the generation of the sequence with large period is rather timing consuming. The command 'debruijn_generator(4,8)' gived no result after running for 8 hours. Any sugestions for this problem? Thank you very much.
In its current form, no, there is no way to force it to generate all possible 4^2 sequences short of exhaustively running the function in a while loop and checking for unique results until all 16 are generated (not particularly efficient, to put it mildly).
@Mahdiyar - from the error you are getting, I'd guess that you haven't put the m-file in a directory that Matlab knows anything about. Either use addpath or place the file in your current directory and it should work just fine.