private double?Selection()
{
Board s = startState;
while (policy.ContainsState(s))
{
Move a = policy.GetMove(s);
// make move. board switches players by itself
Board newBoard;
board.MakeMove(a, out newBoard);
episode.Push(Tuple.Create(s, a));
s = newBoard;
if (s.IsGameOver())
{
return(s.Evaluate(startState.CurrentPlayer));
}
}
// Phase 2. Expand tree
Expansion(s);
return(null);
}
