September 2017 Update

Task/100-doors/MySQL/100-doors.sql

@@ -0,0 +1,37 @@
+DROP PROCEDURE IF EXISTS one_hundred_doors;
+
+DELIMITER |
+
+CREATE PROCEDURE one_hundred_doors (n INT)
+BEGIN
+  DROP TEMPORARY TABLE IF EXISTS doors;
+  CREATE TEMPORARY TABLE doors (
+    id INTEGER NOT NULL,
+    open BOOLEAN DEFAULT FALSE,
+    PRIMARY KEY (id)
+  );
+
+  SET @i = 1;
+  create_doors: LOOP
+    INSERT INTO doors (id, open) values (@i, FALSE);
+    SET @i = @i + 1;
+    IF @i > n THEN
+      LEAVE create_doors;
+    END IF;
+  END LOOP create_doors;
+
+  SET @i = 1;
+  toggle_doors: LOOP
+    UPDATE doors SET open = NOT open WHERE MOD(id, @i) = 0;
+    SET @i = @i + 1;
+    IF @i > n THEN
+      LEAVE toggle_doors;
+    END IF;
+  END LOOP toggle_doors;
+
+  SELECT id FROM doors WHERE open;
+END|
+
+DELIMITER ;
+
+CALL one_hundred_doors(100);