I assume that you can find a point in the space that is in the territory. Call it Z. (Since you have several cities, you can choose the average location of the city as a kind of central place.)
Given the starting point Z, I would think about creating a set of rays from this point, with each ray having a lower and upper bound in size, and a set growing in quantity to get the details. I sketched the diagram below. Nothing about this has been verified; Feel free to suggest improvements.
Theta Z. : Inside Outside, . Inside 0, , , , ( "Horizon" ); , , , , (log2 N ). , , . , , "" .
(theta = North (0), Inside = 0, Outside = Horizon).
R. , R ,
r R, (r) ,
(r) R .
, , .
.
"" .
R = empty
add_to_R(0,0,Horizon)
repeat until done
done = true
for each ray r in R
guess = average(Inside(r),Outside(r))
if guess>threshold
then done = false
if interritory(Z+(Theta(r),guess))
then Inside(r)=guess
else Outside(r)=guess
for each ray r in R
if (distance(Inside(r),Inside(next(r)))> spacing
then add_to_R(average(Theta(r),Theta(next(r)),
min(Inside(r),Inside(next(r)),
max(Outside(r),Outside(next(r))
end
log 2 , , .
; , . , . , , , , , , , .