Upload 199

Author: ggeerraarrdd

README.md

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 [![eevveerryyddaayy release](https://img.shields.io/badge/eevveerryyddaayy-v1.3.0-blue.svg)](https://github.com/ggeerraarrdd/eevveerryyddaayy/)
-[![Solved](https://img.shields.io/badge/solved-198-green.svg)](#index)
+[![Solved](https://img.shields.io/badge/solved-199-green.svg)](#index)
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 # SQL Everyday
@@ -232,6 +232,7 @@ Because this project necessitated a framework to enable consistent daily practic
 | 196   | [Winning Candidate](https://leetcode.com/problems/winning-candidate/description/)                                                                                 | [Solution](solutions/196_winning_candidate.md)                                          | LeetCode    | Medium       |                                                                     |
 | 197   | [Get Highest Answer Rate Question](https://leetcode.com/problems/get-highest-answer-rate-question/)                                                               | [Solution](solutions/197_get_highest_answer_rate_question.md)                           | LeetCode    | Medium       |                                                                     |
 | 198   | [Count Student Number in Departments](https://leetcode.com/problems/count-student-number-in-departments/description/)                                             | [Solution](solutions/198_count_student_number_in_departments.md)                        | LeetCode    | Medium       |                                                                     |
+| 199   | [Tree Node](https://leetcode.com/problems/tree-node/description/)                                                                                                 | [Solution](solutions/199_tree_node.md)                                                  | LeetCode    | Medium       |                                                                     |
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solutions/199_tree_node.md

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+# SQL Everyday \#199
+
+## Tree Node
+
+Site: LeetCode\
+Difficulty per Site: Medium
+
+## Problem
+
+Write a solution to report the type of each node in the tree.
+
+Return the result table in **any order**. [[Full Description](https://leetcode.com/problems/tree-node/description/)]
+
+## Submitted Solution
+
+```sql
+-- Submitted Solution
+WITH cte AS (
+    SELECT
+        t1.id AS node
+        ,COUNT(DISTINCT t1.p_id) AS parent_nodes
+        ,COUNT(DISTINCT t2.p_id) AS child_nodes
+    FROM Tree AS t1
+    LEFT JOIN Tree as t2 ON t1.id = t2.p_id  
+    GROUP BY node
+)
+SELECT
+    node AS id
+    ,CASE WHEN parent_nodes = 0 THEN 'Root'
+        WHEN parent_nodes > 0 AND child_nodes = 0 THEN 'Leaf'
+        ELSE 'Inner' END AS type
+FROM cte 
+;
+```
+
+## Site Solution
+
+```sql
+-- LeetCode Solution 
+-- Approach 1: Using `UNION`
+SELECT
+    id, 'Root' AS Type
+FROM
+    tree
+WHERE
+    p_id IS NULL
+
+UNION
+
+SELECT
+    id, 'Leaf' AS Type
+FROM
+    tree
+WHERE
+    id NOT IN (SELECT DISTINCT
+            p_id
+        FROM
+            tree
+        WHERE
+            p_id IS NOT NULL)
+        AND p_id IS NOT NULL
+
+UNION
+
+SELECT
+    id, 'Inner' AS Type
+FROM
+    tree
+WHERE
+    id IN (SELECT DISTINCT
+            p_id
+        FROM
+            tree
+        WHERE
+            p_id IS NOT NULL)
+        AND p_id IS NOT NULL
+ORDER BY id;
+
+-- Approach 2: Using flow control statement CASE
+SELECT
+    id AS `Id`,
+    CASE
+        WHEN tree.id = (SELECT atree.id FROM tree atree WHERE atree.p_id IS NULL)
+          THEN 'Root'
+        WHEN tree.id IN (SELECT atree.p_id FROM tree atree)
+          THEN 'Inner'
+        ELSE 'Leaf'
+    END AS Type
+FROM
+    tree
+ORDER BY `Id`
+;
+```
+
+## Notes
+
+TBD
+
+## NB
+
+TBD
+
+Go to [Index](../?tab=readme-ov-file#index)\
+Go to [Overview](../?tab=readme-ov-file)