Algorithm
Problem Name: Sql -
In this HackerRank Functions in SQL problem solution,
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:
Code Examples
#1 Code Example with SQL
Code -
SQL
SELECT N, CASE WHEN P IS NULL THEN 'Root'
WHEN(SELECT COUNT(*) FROM BST WHERE P = A.N) > 0 THEN 'Inner'
ELSE 'Leaf'
END
FROM BST A
ORDER BY N;