One embodiment of the present invention provides a system that estimates
the equivalent capacitances for a set of conductors within an electrical
structure. During operation, the system constructs a Gaussian surface
that encloses a first conductor, but does not contain any other
conductor. The system then computes the equivalent capacitance by
constructing a sequence of locations within the electric structure,
wherein the first location in the sequence is on the Gaussian surface,
and the last location in the sequence is on a second conductor in the set
of conductors. Specifically, if a location in the sequence of locations
is on the surface of a neighboring conductor that is not in the set of
conductors, the system can select the next location in the sequence of
locations on a neighboring Gaussian surface that encloses the neighboring
conductor, but does not contain any other conductor. Note that, by
selecting the next location in the sequence of locations on a neighboring
Gaussian surface, the system can quickly reach the second conductor,
thereby quickly estimating the equivalent capacitance by reducing the
computational time required to construct the sequence of locations.