int Searcher::QuiesSearch(Board & cur, int depth, PLAYER who, int alpha, int beta)
{
int i, j;
//可行着法总数
int count;
//对当前着法生成的局面估值；当前层最佳估值
int value;
//用哈希树历史局面记录防止走出循环局面
qshashlink[depth] = cur.zobrist;
for (j = searchDepth; j > 0; j--)
{
if (hashlink[j] == qshashlink[depth])
{
return NO_BEST_MOVE;
}
}
for (j = MAX_QUIES_DEPTH; j > depth; j--)
{
if (qshashlink[j] == qshashlink[depth])
{
return NO_BEST_MOVE;
}
}
if (GameOver(cur) || depth == 0)
{
return Evaluation::Eval(cur, who);
}
value = Evaluation::Eval(cur, who);
if (value >= beta)
{
return beta;
}
if (value > alpha)
{
alpha = value;
}
count = MoveMaker::Make(cur, who, qsmoves[depth]);
if (count == 0)
{
return NO_BEST_MOVE;
}
for (i = 0; i < count; i++)
{
//只对价值大的棋子延伸搜索
if (qsmoves[depth][i].ate == R_KING ||
qsmoves[depth][i].ate == B_KING ||
qsmoves[depth][i].ate == R_KNIGHT ||
qsmoves[depth][i].ate == B_KNIGHT ||
qsmoves[depth][i].ate == R_ROOK ||
qsmoves[depth][i].ate == B_ROOK ||
qsmoves[depth][i].ate == R_CANNON ||
qsmoves[depth][i].ate == B_CANNON
)
{
cur.AddMovement(qsmoves[depth][i]);
value = -QuiesSearch(cur, depth - 1, (PLAYER)1 - who, -beta, -alpha);
cur.DelMovement(qsmoves[depth][i]);
if (value >= beta)
{
return beta;
}
if (value > alpha)
{
alpha = value;
}
}
}
return alpha;
}
int Searcher::PVSearch(Board & cur, int depth, PLAYER who, int alpha, int beta)
{
int i, j;
//可行着法总数
int count;
//对当前着法生成的局面估值；当前层最佳估值
int value, bestvalue;
bestvalue = NO_BEST_MOVE;
//用哈希树历史局面记录防止走出循环局面
hashlink[depth] = cur.zobrist;
for (j = searchDepth; j > depth; j--)
{
if (hashlink[j] == hashlink[depth])
{
return NO_BEST_MOVE;
}
}
if (time(NULL) - startTime > LONGEST_SEARCH_TIME)
{
return TIME_OVER;
}
if (GameOver(cur))
{
return Evaluation::Eval(cur, who);
}
//首先在置换表中查找
// value = Hashnum::SearchTT(cur.zobrist, searchDepth, depth, who, alpha, beta);
// if (value != NOT_IN_TT)
// {
// return value;
// }
if (depth == 0)
{
value = QuiesSearch(cur, MAX_QUIES_DEPTH, who, alpha, beta);
//Hashnum::SaveTT(cur.zobrist, searchDepth, depth, who, EXACT, value);
return value;
}
count = MoveMaker::Make(cur, who, allmoves[depth]);
if (count == 0)
{
return NO_BEST_MOVE;
}
//如果某个着法在上一次迭代中最好，则在下一次迭代中优先计算
if (depth == searchDepth && searchDepth > 1)
{
for (i = 1; i < count; i++)
{
if (allmoves[depth][i].from == lastbest.from && allmoves[depth][i].to == lastbest.to)
{
allmoves[depth][i] = allmoves[depth][0];
allmoves[depth][0] = lastbest;
break;
}
}
}
cur.AddMovement(allmoves[depth][0]);
bestvalue = -PVSearch(cur, depth - 1, (PLAYER)1 - who, -beta, -alpha);
cur.DelMovement(allmoves[depth][0]);
if (depth == searchDepth)
{
good = better;
better = best;
best = allmoves[depth][0];
}
for (i = 1; i < count; i++)
{
if (time(NULL) - startTime > LONGEST_SEARCH_TIME)
{
return TIME_OVER;
}
if (bestvalue < beta)
{
if (bestvalue > alpha)
{
alpha = bestvalue;
}
cur.AddMovement(allmoves[depth][i]);
value = -PVSearch(cur, depth - 1, (PLAYER)1 - who, -alpha - 1, -alpha);
if (value > alpha && value < beta)
{
bestvalue = -PVSearch(cur, depth - 1, (PLAYER)1 - who, -beta, -value);
if (depth == searchDepth)
{
good = better;
better = best;
best = allmoves[depth][i];
}
}
else if (value > bestvalue)
{
bestvalue = value;
if (depth == searchDepth)
{
good = better;
better = best;
best = allmoves[depth][i];
}
}
cur.DelMovement(allmoves[depth][i]);
}
}
//Hashnum::SaveTT(cur.zobrist, searchDepth, depth, who, EXACT, bestvalue);
return bestvalue;
}