int HarmlessPruning(int height)
{
if (HalfMoveClock >= 120)
{
return(0);
}
RepititionResult rep = Repitition();
if (rep != RepititionResult.NONE)
{
return((int)rep);
}
return(-G.MATE + height - 1);
}
//http://blog.sina.com.cn/s/blog_5fd97aa90100vq5p.html
public RepititionResult RuleTest(string filename)
{
Debug.Assert(filename != null);
PgnFileStruct pgn = ReadPgnFile(filename);
FromFEN(pgn.StartFEN);
foreach (MOVE mv in pgn.MoveList)
{
Console.WriteLine(mv);
MakeMove(mv, true);
RepititionResult rep = Repitition();
switch (rep)
{
case RepititionResult.WIN:
if (sdPlayer == 0)
{
Console.WriteLine("黑方负");
}
else
{
Console.WriteLine("红方负");
}
break;
case RepititionResult.LOSE:
if (sdPlayer == 0)
{
Console.WriteLine("黑方胜");
}
else
{
Console.WriteLine("红方胜");
}
break;
case RepititionResult.DRAW:
Console.WriteLine("不变作和");
break;
default:
break;
}
}
return(RepititionResult.NONE);
}
public int SearchQuiesce(int alpha, int beta, int qheight, int height)
{
beta = Math.Min(beta, G.WIN);
stat.QuiesceNodes++;
MOVE mvLast = stepList[stepList.Count - 1].move;
bool isChecked = mvLast.checking;
int best;
IEnumerable <MOVE> moves;
//偶数层是主动方，奇数层是被动方
TransKiller = null;
if (qheight % 2 == 0)
{
if (isChecked)
{
best = -G.MATE + height - 1;
moves = GetNextMove(7, height);
}
else
{
best = Simple_Evaluate();
moves = GetNextMove(3, height);
if (best > beta && mvLast.pcDst == 0 && stepList[stepList.Count - 2].move.pcDst == 0)
{
stat.BetaCutoffs++;
return(best);
}
if (qheight > G.MAX_QUEISCE_DEPTH && mvLast.pcDst == 0)
{
return(best);
}
if (best > alpha)
{
alpha = best;
}
}
}
else
{
if (isChecked) //避免长照
{
RepititionResult rep = Repitition();
if (rep != RepititionResult.NONE)
{
return((int)rep);
}
best = height - G.MATE - 1;
}
else
{
best = Simple_Evaluate();
if (best > beta && mvLast.pcDst == 0 && stepList[stepList.Count - 2].move.pcDst == 0)
{
stat.BetaCutoffs++;
return(best);
}
if (best > alpha)
{
alpha = best;
}
}
//only extend evade and re-capture
if (isChecked)
{
moves = GetNextMove(7, height);
}
else
{
moves = GetNextMove(2, height);
}
}
int vl;
foreach (MOVE mv in moves)
{
//if (!isChecked && height >= RootDepth * 2 && mv.pcDst == 0)
// continue;
Debug.Write(new string('\t', height));
Debug.WriteLine($"{mv} {alpha}, {beta}, {best}, {height}");
MakeMove(mv, false);
if (qheight % 2 == 0)
{
if (stepList[stepList.Count - 1].move.checking)
{
stat.CheckExtesions++;
}
else
{
stat.CaptureExtensions++;
}
}
vl = -SearchQuiesce(-beta, -alpha, qheight + 1, height + 1);
UnmakeMove();
if (vl >= beta)
{
stat.BetaCutoffs++;
SetBestMove(mv, vl, 0, height);
return(vl);
}
if (vl >= best)
{
best = vl;
alpha = Math.Max(alpha, vl);
}
}
return(best);
}