leecode 树的平衡判定 java

以前写过c++版本的，感觉java写的好舒心啊
/**
 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public boolean isBalanced(TreeNode root) {
        if(root==null) return true;
        if(Math.abs(depth(root.left)-depth(root.right))<=1)
        {
            return isBalanced(root.left)&&isBalanced(root.right);

        }
        else
        {
            return false;
        }

    }
    public int depth(TreeNode tn)
    {
        if(tn==null) return 0;
        int le=depth(tn.left);
        int rl=depth(tn.right);
        if(le>=rl) return le+1;
        else return rl+1;

    }
}