algorithms for constructing look-up table labels of de Bruijn sequences by modifying k-th character of Node
Xie Shen-quan · Computer Engineering and Applications Journal · 2008
The structure of de Bruijn sequences is a look-up table whose kernel is its look-up table label.So it is very impor-tant for generating de Bruijn sequences to construct their look-up table labels.This paper presents two methods for constructing m+1-ary n stage look-up table labels based on the k-th character of the node.Method 1 is a construct method by stepping up a fixed value c(1≤c≤m) to the k-th character of the node as its label for most of nodes.Method 2 is a construct method by shrinking the k-th character of node to a fixed value r(0≤r≤m) as its label for most of nodes.The increasing speed of the amount of Look-up table labels constructed by these methods is exponential by m,n.It is still the same as the method by using fixed value labels.It seems that these methods are efficient,but the speed is not worth to say when comparing with the rapid increasing speed of the amount of look-up table labels themselves.The speed of method 2 raises exponential times on m,n compared with the method by using fixed value labels.