[Trigger] Help with making max units

[CheeseOfDoom]

I would like to make a trigger that works like Diablo 2's Lightning Sentry

these are the things im looking for in it
-5 total traps for each specific player
-they must be placed 1 at a time, not 5 at the same time
-they have to be placed at the targeted spot
-have it kill the 1st made trap when you make a new one

the easy way to go about this would be to make the cooldown of the trap laying skill be 1/5th of the duration of the traps. but i dont want a cooldown on the laying of traps

somebody help me out.

 

[Dr Super Good]

Make a FIFO queue ADT. Each hero (or player) is given a separate instance of this structure. When you create traps you enqueue them onto the structure. When the queue length exceeds 5, you dequeue and remove a trap.