Tree- Introduction, Types, Insertion

A tree is a nonlinear hierarchical data structure that consists of nodes connected by edges. Tree Terminologies Node A node is an entity that contains a key or value and pointers to its child nodes. The last nodes of each path are called leaf nodes or external nodes that do not contain a link/pointer to child nodes. The node having at least a child node is called an internal node. Edge It is the link between any two nodes. Types of Tree Binary Tree Binary Search Tree AVL Tree B-Tree public class GFG { static class Node { int key; Node left, right; Node(int key) { this.key = key; left = null; right = null; } } static Node root; static Node temp = root; // Driver code public static void main(String args[]) { root = new Node(10); root.left = new Node(11); root.left.left = new Node(7); root.right = new Node(9); root.right.left = new Node(15); root.right.right = new Node(8); } }