BinaryTree.java

class TreeNode {
    int data;
    TreeNode left, right;

    public TreeNode(int data) {
        this.data = data;
        left = right = null;
    }
}

class BinaryTree {
    TreeNode root;

    BinaryTree() {
        root = null;
    }

    int findHeight(TreeNode node) {
        if (node == null)
            return 0;
        int leftHeight = findHeight(node.left);
        int rightHeight = findHeight(node.right);
        return Math.max(leftHeight, rightHeight) + 1;
    }

    int getHeight() {
        return findHeight(root);
    }
}

public class Main {
    public static void main(String[] args) {
        BinaryTree tree = new BinaryTree();
        tree.root = new TreeNode(1);
        tree.root.left = new TreeNode(2);
        tree.root.right = new TreeNode(3);
        tree.root.left.left = new TreeNode(4);
        tree.root.left.right = new TreeNode(5);

        int height = tree.getHeight();
        System.out.println("Height of the binary tree is: " + height);
    }
}