van Mj Marc Kreveld

Trekking in the Alps without freezing or getting tired

Abstract. Let F be a polyhedral terrain with n vertices. We show how to preprocess F such that for any two query points on F it can be decided whether there exists a path on F between the two points whose height decreases monotonically. More generally, the minimum total ascent or descent along any path between the two points can be computed. It is also possible to decide, given two query points and a height, whether there is a path that stays below this height. All these queries can be answered with one data structure which stores the so-called height-level map of the terrain. Although the height-level map has quadratic worst-case complexity, it is stored implicitly using only linear storage. The query time for all the above queries is

Computing the Maximum Overlap of Two Convex Polygons Under Translations.

O(\log n)

Efficient ray shooting and hidden surface removal

and the structure can be built in

Finding shortest paths in the presence of orthogonal obstacles using a combined L 1 and link metric

O(n\log n)

Algorithmic aspects of proportional symbol maps

time. A path with the desired property can be reported in additional time that is linear in the description size of the path.Let F be a polyhedral terrain with n vertices. We show how to preprocess F such that for any two query points on F it can be decided whether there exists a path on F between the two points whose height decreases monotonically. More generally, the minimum total ascent or descent along any path between the two points can be computed. It is also possible to decide, given two query points and a height, whether there is a path that stays below this height. All these queries can be answered with one data structure which stores the so-called height-level map of the terrain. Although the height-level map has quadratic worst-case complexity, it is stored implicitly using only linear storage. The query time for all the above queries is

Feed-links for network extensions

O(\log n)

A formal approach to the automated labeling of groups of features

and the structure can be built in

Edges and switches, tunnels and bridges

O(n\log n)

Guest Editor's Foreword (Special Issue with Selected Papers from the 19th International Symposium on Graph Drawing, GD 2011)

time. A path with the desired property can be reported in additional time that is linear in the description size of the path.

Finding a minimum stretch of a function

Abstract. Finding a vast array of applications, the list-ranking problem has emerged as one of the fundamental techniques in parallel algorithm design. Surprisingly, the best previously known algorithm to rank a list of n items on a reconfigurable mesh of size