Binary Tree Nodes in SQL | HackerRank Solution

Hello coders, today we are going to solve Binary Tree Nodes HackerRank Solution in SQL.

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.

Column	Type
N	Integer
P	Integer

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

N	P
1	2
3	2
6	8
9	8
2	5
8	5
5	null

Sample Output

1 Leaf
2 Inner
3 Leaf
5 Root
6 Leaf
8 Inner
9 Leaf

Solution – Binary Tree Nodes in SQL

MySQL

SELECT N, IF(P IS NULL,"Root",IF((SELECT COUNT(*) FROM BST WHERE P=B.N)>0,"Inner","Leaf")) FROM BST AS B ORDER BY N;

Disclaimer: The above Problem (Binary Tree Nodes) is generated by Hacker Rank but the Solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.