computational complexity

, Volume 2, Issue 2, pp 133–186

Counting connected components of a semialgebraic set in subexponential time

  • D. Yu. Grigor'ev
  • N. N. VorobjovJr.

DOI: 10.1007/BF01202001

Cite this article as:
Grigor'ev, D.Y. & Vorobjov, N.N. Comput Complexity (1992) 2: 133. doi:10.1007/BF01202001


Let a semialgebraic set be given by a quantifier-free formula of the first-order theory of real closed fields withk atomic subformulae of the typefi≥0 for 1≤ik, where the polynomialsfi∈ℤ[X1,...,Xn] have degrees deg(fi)<d and the absolute value of each (integer) coefficient offi is at most 2M. An algorithm is exhibited which counts the number of connected components of the semialgebraic set in time (M (kd)n20)O (1). Moreover, the algorithm allows us to determine whether any pair of points from the set are situated in the same connected component.

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Copyright information

© Birkhäuser Verlag 1992

Authors and Affiliations

  • D. Yu. Grigor'ev
    • 1
  • N. N. VorobjovJr.
    • 1
  1. 1.V. A. Steklov Mathematical InstituteAcademy of SciencesSt. PetersburgRussia
  2. 2.Department of Computer SciencePennsylvania State UniversityState CollegeUSA