What I have to modify if the two players make actions at once?

[paisano55]

First of all, sorry for my English.

I'm modifying these codes for my school competition.
However, in the rule, both two players do action at once.
I am stuck at modifying MCTS.
Both sides' pieces have to move at once. It means that best action A of current state S contains both players' action.
Therefore, here's the problem. Player can only move their pieces (=send action to board).

How can I handle it?
Plz give me some ideas.