From d29b7448b40557bd362af481351ec2441c370882 Mon Sep 17 00:00:00 2001
From: Vikas Chitturi - Open Source Contributor <vikasch.1994@gmail.com>
Date: Sun, 9 Jun 2024 18:01:04 +0530
Subject: [PATCH] Medium LC Problem = ConsecutiveNumbers.sql

---
 LeetCode/SQL50/ConsecutiveNumbers.sql | 56 +++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 LeetCode/SQL50/ConsecutiveNumbers.sql

diff --git a/LeetCode/SQL50/ConsecutiveNumbers.sql b/LeetCode/SQL50/ConsecutiveNumbers.sql
new file mode 100644
index 0000000..7042380
--- /dev/null
+++ b/LeetCode/SQL50/ConsecutiveNumbers.sql
@@ -0,0 +1,56 @@
+-- Table: Logs
+
+-- +-------------+---------+
+-- | Column Name | Type    |
+-- +-------------+---------+
+-- | id          | int     |
+-- | num         | varchar |
+-- +-------------+---------+
+-- In SQL, id is the primary key for this table.
+-- id is an autoincrement column.
+ 
+-- Find all numbers that appear at least three times consecutively.
+
+-- Return the result table in any order.
+
+-- The result format is in the following example.
+
+-- Example 1:
+
+-- Input: 
+-- Logs table:
+-- +----+-----+
+-- | id | num |
+-- +----+-----+
+-- | 1  | 1   |
+-- | 2  | 1   |
+-- | 3  | 1   |
+-- | 4  | 2   |
+-- | 5  | 1   |
+-- | 6  | 2   |
+-- | 7  | 2   |
+-- +----+-----+
+-- Output: 
+-- +-----------------+
+-- | ConsecutiveNums |
+-- +-----------------+
+-- | 1               |
+-- +-----------------+
+-- Explanation: 1 is the only number that appears consecutively for at least three times.
+
+-- Write your PostgreSQL query statement below
+-- Solution
+with computed_tb as (
+    select X.id Xid,
+            X.num Xnum,
+            Y.id Yid,
+            Y.num Ynum,
+            Y.id - X.id as diff
+        from Logs X cross join Logs Y 
+        where Y.id - X.id in (1) and X.num = Y.num
+)
+select distinct A.Xnum as ConsecutiveNums
+from computed_tb A join computed_tb B on (A.Xid = B.Yid) 
+where A.Xnum in (
+    select Xnum from computed_tb group by Xnum having count(Xnum) >= 2
+)