BalancedTree.java

package swe.Tree;

public class BalancedTree {
    public boolean isBalanced(TreeNode root) {
        if (root == null) {
            return true;
        }
        int leftHeight = getHeight(root.left);
        int rightHeight = getHeight(root.right);

        if (Math.abs(leftHeight - rightHeight) > 1) {
            return false;
        }
        return isBalanced(root.left) && isBalanced(root.right);
    }

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

    public static void main(String[] args) {
        TreeNode root = new TreeNode(1);
            root.left = new TreeNode(2);
            root.right = new TreeNode(3);
            root.right.left = new TreeNode(4);
            root.right.right = new TreeNode(5);
            root.right.right.right = new TreeNode(7);

        BalancedTree bt = new BalancedTree();
        System.out.println(bt.isBalanced(root)); // false
    }
}