面试题：平衡二叉树

public class Solution {
    public boolean IsBalanced_Solution(TreeNode root) {
        if(root==null) return true;
        int left=depth(root.left);
        int right=depth(root.right);
        int balance=left-right;
        if(balance>1||balance<-1)
            return false;
        else
            return true;
    }
    public int depth(TreeNode root){
        if(root==null) return 0;
        int left=depth(root.left);
        int right=depth(root.right);
        return left>right?(left+1):(right+1);
    }
}