Binary tree always has nodes with maximum children of 2. Index starts with 1 such that index of j is 1, f is 2, z is 7 and so on. Root is single node always on top of the tree, in this case its j.

A tree is a data structure where a node can have zero or more children. Each node contains a value, and similar to graphs each node can have a connection between other nodes called an edge. A tree is ...