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Generalized intersection searching problems. (English) Zbl 0777.68078

A new class of geometric intersection searching problem is introduced, which generalizes previously considered intersection searching problems and is rich in applications. In a standard intersection searching problem, a set \(S\) of \(n\) geometric objects is to be preprocessed so that the objects that are intersected by a query object \(q\) can be reported efficiently. In a generalized problem, the objects in \(S\) come aggregated in disjoint groups and what is of interest are the groups, not the objects, that are intersected by \(q\). Although this problem can be solved easily by using an algorithm for the standard problem, the query time can be \(\Omega(n)\) even though the output size is just \(O(1)\).
Algorithms with efficient, output size sensitive query times are presented for the generalized version of a number of intersection searching problems, including: interval intersection searching, orthogonal segment intersection searching, orthogonal range searching, point enclosure searching, rectangle intersection searching, and segment intersection searching. In addition, the algorithms are also space efficient.
Reviewer: R.Janardan

MSC:

68U05 Computer graphics; computational geometry (digital and algorithmic aspects)
68Q25 Analysis of algorithms and problem complexity
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