题解 | #判断是不是平衡二叉树#

using System;
using System.Collections.Generic;

/*
public class TreeNode
{
	public int val;
	public TreeNode left;
	public TreeNode right;

	public TreeNode (int x)
	{
		val = x;
	}
}
*/

class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param pRoot TreeNode类 
     * @return bool布尔型
     */
    public bool IsBalanced_Solution (TreeNode pRoot) {
        return IsBalanced2(pRoot) == -1 ? false:true;
    }
    public int IsBalanced2(TreeNode root){
        if(root == null) return 0;
        int right = IsBalanced2(root.right);
        int left = IsBalanced2(root.left);
        if(left == -1 || right == -1 || Math.Abs(right - left) > 1) return -1;
        return (Math.Max(left, right) + 1);
    }
}