1 The Power of Grids - Computing the Minimum Disk Containing $k$ Points

Theorem 1.2.3 For set P of n points in the plane, one can compute the closest pair of P in expected linear time.

3 Well Separated Pairs Decomposition

The Well-Separated Pair Decomposition and Its Applications

4 Clustering - Definitions and Basic Algorithms

4.2 On $k$-center clustering

The $k$-center clustering is NP-Hard.

A simple 2-approximation algorithm