LeetCode || 平衡二叉树

平衡二叉树

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    int right = 0;
    int left = 0;
    public boolean isBalanced(TreeNode root) {
        if(root == null||(root.right==null&&root.left==null)){
            return true;
        }else if(Math.abs(right-left)>1){
            return false;
        }else{
            right++;
            left++;
            isBalanced(root.left);
            isBalanced(root.right);
        }
        return true;
    }
}

正确的

class Solution {
    public boolean isBalanced(TreeNode root) {
        if(root==null) return true;
        if(Math.abs(Depth(root.left)-Depth(root.right))>1) return false;
        else return isBalanced(root.left)&&isBalanced(root.right);
    } 
    private int Depth(TreeNode root){//求深度
        if(root==null) return 0;
        return Math.max(Depth(root.left),Depth(root.right))+1;
    }
}