The Point Quadtree index structure is illustrated in three successive states. Each Node has four cells that represent four compass points (at positions 1, 2, 3, and 4); these may or may not point to child Nodes.
State 1:
Top (root) Node has a position 1 pointer to a child Node
The child Node has a position 3 pointer to Node A
State 2: Same as State 1, and the following:
Top (root) Node has a position 3 pointer to another child Node
This child Node has a position 3 pointer to Node B
State 3: Same as State 2, and the following:
Top (root) Node has a position 4 pointer to yet another child Node
This child Node has a position 3 pointer to Node C