题解 | #判断是不是平衡二叉树#

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 *   public TreeNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public 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 boolean IsBalanced_Solution (TreeNode pRoot) {
        // write code here
        return judge(pRoot);
    }
//    {1,2,3,4,5,#,#,#,#,6}
    public int depth(TreeNode pRoot){
        if(pRoot != null){
            if(pRoot.left != null && pRoot.right != null){
                return Math.max(depth(pRoot.left), depth(pRoot.right)) + 1;
            }else if(pRoot.left != null){
                return depth(pRoot.left) + 1;
            }else if(pRoot.right != null){
                return depth(pRoot.right) + 1;
            }else{
                return 1;
            }
        }else{
            return 0;
        }
    }
    public boolean judge(TreeNode pRoot){
        if(pRoot != null){
            return (Math.abs(depth(pRoot.left) - depth(pRoot.right)) <=1) && judge(pRoot.left) && judge(pRoot.right);
        }else{
            return true;
        }
    }
}