public static List <RecRateResult> recRate(State2048 root, int depth)
{
List <StateTrans> moves = root.getAllMoveStates();
//If we can't move, the game is over; worst penalty
if (moves.Count == 0)
{
return new List <RecRateResult> {
new RecRateResult(double.MaxValue, MoveDir.Self)
}
}
;
//If the depth is zero, return the result from this state
if (depth == 0)
{
return new List <RecRateResult> {
new RecRateResult(root.rate(), MoveDir.Self)
}
}
;
List <RecRateResult> result = new List <RecRateResult>();
foreach (StateTrans st in moves)
{
double bestOfWorst = double.MaxValue;
List <State2048> allRandom = st.state.getAllRandom();
foreach (State2048 rand in allRandom)
{
List <RecRateResult> randRes = recRate(rand, depth - 1);
//Take the maximum penalty
double worstRate = randRes[0].rating;
for (int i = 1; i < randRes.Count; i++)
{
if (randRes[i].rating > worstRate)
{
worstRate = randRes[i].rating;
}
}
if (worstRate < bestOfWorst)
{
bestOfWorst = worstRate;
}
}
result.Add(new RecRateResult(bestOfWorst, st.dir));
}
return(result);
}
public static double alphabetarate(State2048 root, int depth, double alpha, double beta, bool player)
{
if (depth == 0)
{
return(root.rate());
}
if (player)
{
List <StateTrans> moves = root.getAllMoveStates();
//If we can't move, the game is over; worst penalty
if (moves.Count == 0)
{
return(double.MaxValue);
}
foreach (StateTrans st in moves)
{
alpha = Math.Min(alpha, alphabetarate(st.state, depth - 1, alpha, beta, !player));
if (beta >= alpha)
{
break;
}
}
return(alpha);
}
else
{
List <State2048> moves = root.getAllRandom();
foreach (State2048 st in moves)
{
beta = Math.Max(beta, alphabetarate(st, depth - 1, alpha, beta, !player));
if (beta <= alpha)
{
break;
}
}
return(beta);
}
}