Quadtree

Quadtree --- кваддерево.

A quadtree is a ternary tree representing a hierarchical decomposition of the plane, originally proposed for representing point sets. Each node of the quadtree corresponds to a square region, called a box. The root usually corresponds to the smallest enclosing square of the given set of objects. A node of the quadtree acquires four children, when its associated box is split into its four quadrants.