# 0608. Tree Node

<https://leetcode.com/problems/tree-node>

## Description

Given a table `tree`, **id** is identifier of the tree node and **p\_id** is its parent node's **id**.

```

+----+------+
| id | p\_id |
+----+------+
| 1  | null |
| 2  | 1    |
| 3  | 1    |
| 4  | 2    |
| 5  | 2    |
+----+------+
```

Each node in the tree can be one of three types:

* Leaf: if the node is a leaf node.
* Root: if the node is the root of the tree.
* Inner: If the node is neither a leaf node nor a root node.

Write a query to print the node id and the type of the node. Sort your output by the node id. The result for the above sample is:

```

+----+------+
| id | Type |
+----+------+
| 1  | Root |
| 2  | Inner|
| 3  | Leaf |
| 4  | Leaf |
| 5  | Leaf |
+----+------+
```

**Explanation**

* Node '1' is root node, because its parent node is NULL and it has child node '2' and '3'.
* Node '2' is inner node, because it has parent node '1' and child node '4' and '5'.
* Node '3', '4' and '5' is Leaf node, because they have parent node and they don't have child node.
* And here is the image of the sample tree as below:

```

			  1
			/   \
                      2       3
                    /   \
                  4       5
```

**Note**

If there is only one node on the tree, you only need to output its root attributes.

## ac

```java
```