Tree_HeightOfABinaryTree.java

/*
Problem Statement: Tree: Height of a Binary Tree
Given the root node of a binary tree, you are required to compute the height of the tree. The height of a binary tree is defined as the number of edges on the longest path from the root node to a leaf node. A leaf is a node with no children.

Input Format:
The input consists of a number of integers. The first integer, n, indicates the number of nodes in the tree.
The subsequent n integers represent the values of the nodes, which are inserted into the tree following the rules of a binary search tree.

Output Format:
The output should be a single integer representing the height of the binary tree.

Constraints:
The number of nodes in the tree can range from 1 to 1000.
The value of each node will be a positive integer.
*/

import java.util.*;
import java.io.*;

class Node {
 Node left;
 Node right;
 int data;
 
 Node(int data) {
 this.data = data;
 left = null;
 right = null;
 }
}

class Tree_HeightOfABinaryTree {

	/*
 class Node 
 	int data;
 	Node left;
 	Node right;
	*/
	public static int height(Node root) 
 {
 	// Write your code here.
 if(root == null)
 {
 return -1;
 // break;
 }
 
 int leftHeight = height(root.left);
 int rightHeight = height(root.right);
 
 return Math.max(leftHeight, rightHeight) + 1;
 }

	public static Node insert(Node root, int data) {
 if(root == null) {
 return new Node(data);
 } else {
 Node cur;
 if(data <= root.data) {
 cur = insert(root.left, data);
 root.left = cur;
 } else {
 cur = insert(root.right, data);
 root.right = cur;
 }
 return root;
 }
 }

 public static void main(String[] args) {
 Scanner scan = new Scanner(System.in);
 int t = scan.nextInt();
 Node root = null;
 while(t-- > 0) {
 int data = scan.nextInt();
 root = insert(root, data);
 }
 scan.close();
 int height = height(root);
 System.out.println(height);
 }	
}