Chapter 20, Problem 21RQE

Explanation of Solution

Binary tree:

A complete binary tree is a tree with the property that every node must have exactly two children, and at the last level, the nodes should be from left to right. But an incomplete binary tree has a node with zero or one or two children.

• First node must be the root of the tree.
• The second node must be the left child of the root
• The third node must always be the right child of the root.
• The next node must start to fill the next level from left to right.
• But, here it is important to note that not all the nodes in the binary tree have two children. Some may have single node or some may not have any nodes...