平衡二叉树

题目描述

输入一棵二叉树，判断该二叉树是否是平衡二叉树。

/**
 * 
 * @author gentleKay
 * 题目描述
 * 输入一棵二叉树，判断该二叉树是否是平衡二叉树。
 * 平衡二叉树的性质：
 * 它是一棵空树或它的左右两个子树的高度差的绝对值不超过1，并且左右两个子树都是一棵平衡二叉树。
 */

public class Main38 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        TreeNode root = new TreeNode(1);
        root.left = new TreeNode(2);
        root.left.left = new TreeNode(4);
        root.left.right = new TreeNode(5);
    
//        root.right = new TreeNode(3);
//        root.right.right = new TreeNode(6);
//        root.right.right.right = new TreeNode(7);
//        root.right.right.right.right = new TreeNode(8);
        boolean flag = Main38.IsBalanced_Solution(root);
        System.out.println(flag);
    }
    
    public static class TreeNode {
        int val = 0;
        TreeNode left = null;
        TreeNode right = null;

        public TreeNode(int val) {
            this.val = val;
        }
    }
    
    public static boolean IsBalanced_Solution(TreeNode root) {
        if (root == null) {
            return true;
        }
        int left = Depth(root.left);
        int right = Depth(root.right);
        if (Math.abs(left-right) > 1) {
            return false;
        }
        return true;
    }
    
    public static int Depth(TreeNode root) {
        if (root == null) {
            return 0;
        }
        int a = Depth(root.left)+1;
        int b = Depth(root.right)+1;
        return a>b ? a:b;
    }

}