Quote:
Originally Posted by ilya239
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?

This approach confuses my understanding of the problem. Why doesn't the symmetry of the problem reduce it to 1D (r instead of x) with two parameters, i.e. the "positive intervals" case in example 2.2.2?
Thanks