What is a Binary Tree?

Introduction

A tree in which each node can have a maximum of two children is known as a binary tree. We can refer to these children as the left and the right child. The figure below shows what a Binary Tree looks like :

Types of Binary Trees

Complete Binary Trees

A complete binary tree is a binary tree in which all the levels of the tree are fully filled, except for perhaps the last level, which can be filled from left to right. The total number of nodes in a complete binary tree can be expressed as:

$$2^{h} \leq \text{total number of nodes} \leq 2^{(h+1)}-1$$ ...