N. Katoh

collaborators

2 papers

cs.DM2008

Covering Directed Graphs by In-trees

Naoyuki Kamiyama, Naoki Katoh

Given a directed graph $D = (V, A)$ with a set of $d$ specified vertices $S = {s_{1}, ..., s_{d}} \subseteq V$ and a function $f : S \to Z_{+}$ where $Z_{+}$ denotes the se…

cs.CG2001

Notes on computing peaks in k-levels and parametric spanning trees

Naoki Katoh, Takeshi Tokuyama

We give an algorithm to compute all the local peaks in the $k$ -level of an arrangement of $n$ lines in $O (n lo g n) + O ~ ((k n)^{2/3})$ time. We can also find $τ$ largest peak…