Abstract
We study the number of records in random split trees on $n$ randomly labelled vertices. Equivalently the number of random cuttings required to eliminate an arbitrary random split tree can be studied. After normalization the distributions are shown to be asymptotically $1$-stable. This work is a generalization of our earlier results for the random binary search tree which is one specific case of split trees. Other important examples of split trees include $m$-ary search trees, quadtrees, median of $(2k+1)$-trees, simplex trees, tries and digital search trees.
Highlights
We study the number of records in random split trees which were introduced by Devroye [2]
We recently showed that Janson’s approach could be applied for the random binary search tree [6]
In split trees on the other hand most vertices are close to the depth ∼ c ln n, where c is a constant; for the binary search tree that we investigated in [6] this depth is ∼ 2 ln n (e.g. [3])
Summary
We study the number of records in random split trees which were introduced by Devroye [2]. Given a rooted tree T with n nodes, let each vertex v have a random value λv attached to it, and assume that these values are i.i.d. with a continuous distribution. We say that a vertex v is a leaf in a split tree if the node itself holds at least one ball but no descendants of v hold any balls. When all the N balls have been distributed we end up with a split tree with a finite number of nodes which we denote by the parameter n. (i) If v is not a leaf, choose child i with probability Vi and recursively add the ball to the subtree rooted at child i, by the rules given in steps (i), (ii) and (iii).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have