[HackerRank] Binary Tree Nodes

https://www.hackerrank.com/challenges/binary-search-tree-1/problem

Binary Tree Nodes | HackerRank

 

Code 1 

SELECT N,
(CASE 
    WHEN P IS NULL THEN "Root"
    WHEN N IN (SELECT P FROM BST) THEN "Inner"
    ELSE "Leaf" 
END) as R
FROM BST
ORDER BY N;

Code 2

SELECT N, 
IF(P IS NULL, 'Root', IF(B.N IN (SELECT P FROM BST), 'Inner', 'Leaf')) 
FROM BST AS B
ORDER BY N;