Issue No. 07 - July (1999 vol. 48)

ISSN: 0018-9340

pp: 738-743

DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/12.780881

ABSTRACT

<p><b>Abstract</b>—<tmath>$(a,b)$</tmath>-trees are an important class of search trees. They include 2-3 trees, 2-3-4 trees, and <tmath>$B$</tmath>-trees as subclasses. We show that a space-minimum <tmath>$(a,b)$</tmath>-tree is also height-minimum and present an optimal algorithm for constructing <tmath>$(a,b)$</tmath>-trees that are height-minimum and space-minimum. Given <tmath>$n$</tmath> keys, our algorithm constructs an <tmath>$(a,b)$</tmath>-tree with minimum height and fewest possible nodes. Our algorithm takes <tmath>$\Theta(n)$</tmath> time if the keys in <tmath>$S$</tmath> are sorted and <tmath>$\Theta(n \log n )$</tmath> time if the keys are not sorted. We also discuss possible applications of our algorithm.</p>

INDEX TERMS

2-3 trees, 2-3-4 trees, algorithms, $(a, b)$-trees, $B$-trees, databases, data structures, indexing, search trees, tree construction.

CITATION

S.q. Zheng, M. Sun, "Constructing Optimal Search Trees in Optimal Time",

*IEEE Transactions on Computers*, vol. 48, no. , pp. 738-743, July 1999, doi:10.1109/12.780881