Search results for "Restricted words"

Gray codes and efficient exhaustive generation for several classes of restricted words

2015

We consider Gray codes and efficient exhaustive generating algorithms for the sets belonging to three major classes of restricted words, that are: (1) restricted growth sequences, (2) factor avoiding q-ary words, and (3) pattern avoiding permutations. For the first two classes, our Gray codes (and thus, our generating algorithms) are based on order relations obtained by specializing known order relations; namely Reflected Gray Code (RGC) order and its variations, and we call them Reflected Gray Code based orders. The Gray code and the generating algorithm for the third class are based on Steinhaus-Johnson-Trotter order, that is, order relation induced by Steinhaus-Johnson-Trotter Gray code …