height.java

package day4;

import parent_class.*;

public class height {
    public static int treeheight(TreeNode root) {
        if (root == null)
            return 0;
        if (root.left == null && root.right == null) {
            return 1;
        }
        return 1 + Math.max(treeheight(root.left), treeheight(root.right));

    }

    // method to invert a binary tree
    public static TreeNode invertTree(TreeNode root) {
        if (root == null) {
            return null;
        }
        TreeNode temp = root.left;
        root.left = root.right;
        root.right = temp;
        invertTree(root.left);
        invertTree(root.right);
        return root;
    }

    public static TreeNode swap(TreeNode root) {
        if (root == null)
            return null;
        TreeNode temp = root.left;
        root.left = root.right;
        root.right = temp;
        swap(root.left);
        swap(root.right);
        return root;

    }

    public static void main(String[] args) {
        TreeNode root = new TreeNode(1);
        root.left = new TreeNode(2);
        root.right = new TreeNode(3);
        root.left.left = new TreeNode(4);

        int res = treeheight(root);
        System.out.println(res);

    }

}