Automatically spawn joined player on his spawn?

Hello, I am wondering how I would do like SkyWars spawning, when you join, then it puts you automatically to your own island and when another join then he joins on another island and so on..?

 

Where's your code ?

 

• Get all the locations or make a int that can increment and be multiplied to get the location that doesn't belong to someone.
• OnJoin p.teleport(Location);
• Spawn the blocks (if needed)

 

Tried that, but when player decides to quit then the int stays still as it was, so when another player joins then he don't get disconnected player's island.

 

The make an on Quit and reduces the int. Or make a Map that stores an Integer, UUID (Int the island, The UUId the player)

Although, If you want, you can do the reverse and make a UUID,Integer, map to assign one island to one player always.