Quote:
Originally Posted by yaser
Correct. To be exact about inside and and outside, the perimeters of the inner circle and the outer circle are included in the region.

So once the set of N points is fixed, and we pick different subsets of the N points and try to cover them with "donuts"  all donuts must be centered at the same point? We can't use a donut centered at p1 to cover {x1,x2} but a donut centered at a different point p2 to cover {x3,x4}? In other words, after picking N points, we pick ONE origin, and _then_ can pick donuts centered at that origin only?