63 lines
1014 B
Markdown
63 lines
1014 B
Markdown
---
|
|
layout: page
|
|
title: SQL Binary Tree Nodes
|
|
last_solved:
|
|
category: sql
|
|
leetcode_url: https://www.hackerrank.com/challenges/binary-search-tree-1
|
|
status: Attempted
|
|
---
|
|
|
|
Problem
|
|
-------
|
|
|
|
```
|
|
You are given a table, BST, containing two columns: N and P, where N represents the value of a node in Binary Tree, and P is the parent of N.
|
|
|
|
|
|
|
|
Write a query to find the node type of Binary Tree ordered by the value of the node. Output one of the following for each node:
|
|
|
|
Root: If node is root node.
|
|
Leaf: If node is leaf node.
|
|
Inner: If node is neither root nor leaf node.
|
|
Sample Input
|
|
|
|
|
|
|
|
Sample Output
|
|
|
|
1 Leaf
|
|
2 Inner
|
|
3 Leaf
|
|
5 Root
|
|
6 Leaf
|
|
8 Inner
|
|
9 Leaf
|
|
|
|
Explanation
|
|
|
|
The Binary Tree below illustrates the sample:
|
|
|
|
```
|
|
|
|
Solution
|
|
----------
|
|
|
|
{% highlight sql %}
|
|
|
|
select n,
|
|
case
|
|
when p is null then 'Root'
|
|
-- case when n not in (2,6,4,15,9,13,11) then 'Leaf' else 'Inner'
|
|
when n in (select distinct p from bst) then 'Inner'
|
|
else 'Leaf'
|
|
end
|
|
|
|
end
|
|
from bst
|
|
order by n;
|
|
|
|
{% endhighlight %}
|
|
|
|
|
|
![image1]() |