[N-0] add 603

Author: fishercoder1534

README.md

@@ -675,6 +675,7 @@ Your ideas/fixes/algorithms are more than welcome!
 |610|[Triangle Judgement](https://leetcode.com/problems/triangle-judgement/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_610.java) | | | Easy | 
 |608|[Tree Node](https://leetcode.com/problems/tree-node/)|[Solution](../master/database/_608.sql) | | | Medium | Union
 |607|[Sales Person](https://leetcode.com/problems/sales-person/)|[Solution](../master/database/_607.sql) | | | Easy |
+|603|[Consecutive Available Seats](https://leetcode.com/problems/sales-person/)|[Solution](../master/database/_603.sql) | | | Easy |
 |602|[Friend Requests II: Who Has the Most Friends](https://leetcode.com/problems/friend-requests-ii-who-has-the-most-friends/)|[Solution](../master/database/_602.sql) | | | Medium |
 |601|[Human Traffic of Stadium](https://leetcode.com/problems/human-traffic-of-stadium/)|[Solution](../master/database/_601.sql) | | | Hard |
 |597|[Friend Requests I: Overall Acceptance Rate](https://leetcode.com/problems/friend-requests-i-overall-acceptance-rate/)|[Solution](../master/database/_597.sql) | | | Easy |

database/_603.sql

@@ -0,0 +1,30 @@
+--603. Consecutive Available Seats
+--
+--Several friends at a cinema ticket office would like to reserve consecutive available seats.
+--Can you help to query all the consecutive available seats order by the seat_id using the following cinema table?
+--
+--| seat_id | free |
+--|---------|------|
+--| 1       | 1    |
+--| 2       | 0    |
+--| 3       | 1    |
+--| 4       | 1    |
+--| 5       | 1    |
+--Your query should return the following result for the sample case above.
+--| seat_id |
+--|---------|
+--| 3       |
+--| 4       |
+--| 5       |
+--Note:
+--The seat_id is an auto increment int, and free is bool ('1' means free, and '0' means occupied.).
+--Consecutive available seats are more than 2(inclusive) seats consecutively available.
+
+select c.seat_id from cinema c where c.free = 1
+and
+(
+    c.seat_id+1 in (select seat_id from cinema where free=1)
+    or
+    c.seat_id-1 in (select seat_id from cinema where free=1)
+)
+order by c.seat_id