bool operator()(move a, move b)
{
if (base.moveGains(a) > base.moveGains(b))
return true;
if (base.moveGains(a) < base.moveGains(b))
return false;
return b < a;
}
bool operator()(pair<int, move> a, pair<int, move> b)
{
if (a.first > b.first)
return true;
if (a.first < b.first)
return false;
if (base.moveGains(a.second) > base.moveGains(b.second))
return true;
if (base.moveGains(a.second) < base.moveGains(b.second))
return false;
return b.second < a.second;
}
int quiesence(board b, int alpha, int beta, bool hasPass)
{
if (b.inCheck().first || b.inCheck().second)
return minimax(1, b, alpha, beta, 0);
lookupResult res;
bool haveHit = queryTable(b, res);
int bestSoFar;
if (hasPass)
{
alpha = max(b.eval(), alpha);
if (alpha >= beta)
return alpha;
if (haveHit)
{
if (res.type == SCORE_LOWERBOUND)
{
if (res.evaluation >= beta)
return -res.evaluation;
else
alpha = max(alpha, res.evaluation);
}
if (res.type == SCORE_UPPERBOUND)
{
if (res.evaluation <= alpha)
return -alpha;
else
beta = min(beta, res.evaluation);
}
if (res.type == SCORE_EXACT)
return -max(alpha, res.evaluation);
}
bestSoFar = alpha;
}
else
{
if (haveHit)
{
if (res.type == SCORE_LOWERBOUND)
{
if (res.evaluation >= beta)
return -res.evaluation;
else
alpha = max(alpha, res.evaluation);
}
if (res.type == SCORE_UPPERBOUND)
{
if (res.evaluation <= alpha)
return -res.evaluation;
else
beta = min(beta, res.evaluation);
}
if (res.type == SCORE_EXACT)
return -res.evaluation;
}
b.flipToMove();
bestSoFar = quiesence(b, -beta, -alpha, true);
b.flipToMove();
}
vector<move> moves = b.genMoves();
moveOrderer order(b);
sort(moves.begin(), moves.end(), order);
int besti = 0;
for (int i=0; i<moves.size(); i++)
{
if (b.moveGains(moves[i]) < 300)
break;
board temp = b;
temp.executeMove(moves[i]);
int curScore = quiesence(temp, -beta, -max(alpha, bestSoFar), false);
if (curScore > bestSoFar)
{
bestSoFar = curScore;
besti = i;
}
if (bestSoFar >= beta)
break;
}
putTable(b, 0, bestSoFar, moves[besti], alpha, beta);
return -bestSoFar;
}