Geometric Searching over the Rationals

نویسنده

  • Bernard Chazelle
چکیده

We revisit classical geometric search problems under the assumption of rational coordinates. Our main result is a tight bound for point separation, ie, to determine whether n given points lie on one side of a query line. We show that with polynomial storage the query time is Θ(log b/ log log b), where b is the bit length of the rationals used in specifying the line and the points. The lower bound holds in Yao’s cell probe model with storage in n and word size in b. By duality, this provides a tight lower bound on the complexity on the polygon point enclosure problem: given a polygon in the plane, is a query point in it?

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تاریخ انتشار 1999