# algorithms – Relation between checking connectivity set of \$n\$ unit disks and voronoi diagram

I am interested in Computational Geometry and read some resource in internet to become professional. Suppose given $$n$$ unit disk in plane. Each center of disk is the site of that disk. We say disks are connected if for each site $$p,q$$ there is path between $$p,q$$. Two disk if that have intersect, then they are connected. We must describe an algorithm in $$O(nlog n)$$ for checking are disk is connected or not? How we can use voronoi diagram? Because i think there is a relation between this problem and voronoi diagram.

Reference for this question is problem 5 of this document :