What is a Tree?
Data structures, amongst other things, are used to store and organize data. Different types of data are more efficiently organized using particular data structures.
Trees are non-linear data structures which are quite often used to represent hierarchical data such as the employee organizational structure in a company.
Structure of a Tree:
A collection of entities called nodes (represented as circles in our diagrams) are linked together with an edge to simulate a hierarchical structure. Each node contains data that can be of any type as long as all the nodes contain the same type of data.
Components of a Tree:
Root: A node with no incoming link to another node, i.e. no parent.
Child: A node with an incoming link from an upper node, i.e. a parent node. A child can only have one parent.
Parent: A node with an outgoing link to a lower node, i.e. a child node. A parent can have multiple children.
Siblings: Children nodes with the same parent.
Leaf: A node with no outgoing link to a lower node, i.e. no child node.
Depth: The depth of a node, ‘x’, is the number of edges (links) in the path from the root node to the node ‘x’. In the example on the right, the depth of node ‘x’ is 2.
