Tree

• A set of linked nodes that form a hierarchy• There is a root node at the top• Each node may or may not have children• In some types of trees a node may have any number of

children and in other types the number of children are controlled

• The nodes at the bottom most level are called leaf nodes• The nodes between the root and the leaf nodes are called

internal nodes• A subtree is a portion of a tree that can be viewed as a

complete tree in itself.

Tree

• Traversal– Breadth first• Visit all the nodes at a given level

before going deeper

– Depth first• Visit nodes as deep as possible

first

Trees

• Binary tree– Each node has at most two

children

class

title

instructor

semester

assignment*

title

instructions

grading

student*

name

first

middle?

lastfeedback?

grade?