Title
On the Maximal Number of Cubic Subwords in a String
Abstract
We investigate the problem of the maximum number of cubic subwords (of the form www) in a given word. We also consider square subwords (of the form ww). The problem of the maximum number of squares in a word is not well understood. Several new results related to this problem are produced in the paper. We consider two simple problems related to the maximum number of subwords which are squares or which are highly repetitive; then we provide a nontrivial estimation for the number of cubes. We show that the maximum number of squares xx such that x is not a primitive word (nonprimitive squares) in a word of length n is exactly $\left\lfloor \frac{n}{2}\right\rfloor - 1$, and the maximum number of subwords of the form x k , for k 驴 3, is exactly n 驴 2. In particular, the maximum number of cubes in a word is not greater than n 驴 2 either. Using very technical properties of occurrences of cubes, we improve this bound significantly. We show that the maximum number of cubes in a word of length n is between $\frac{45}{100}\;n$ and $\frac{4}{5}\;n$.
Year
DOI
Venue
2009
10.1007/978-3-642-10217-2_34
Clinical Orthopaedics and Related Research
Keywords
DocType
Volume
primitive word,maximal number,new result,nontrivial estimation,nonprimitive square,form ww,square subwords,length n,cubic subwords,maximum number,simple problem
Conference
abs/0911.1370
ISSN
Citations 
PageRank 
0302-9743
8
1.26
References 
Authors
22
4
Name
Order
Citations
PageRank
Marcin Kubica162929.26
Jakub Radoszewski262450.36
Wojciech Rytter32290181.52
Tomasz Waleń470639.62