public virtual int AlphaBeta(Position p, int depth, int alpha, int beta, double extension, MoveList pv, long Zkey, int move)
{
if (nodecount[1] + nodecount[0] > NODELIMIT) //wenn Knotenlimit überschritten, gehe zu Exception
{
throw new TooManyNodesException();
}
if (depth < maxDepth)
{
maxDepth = depth;
}
p.makeMove(move);
nodecount[0] += 1;
int hashflag = HASHALPHA;
//letzte Bits des Keys in Index umwandeln
int index = (int)Zkey & (HASHSIZE - 1);
//Hash Tables
hvalue = -1;
bestMove = -1;
newbeta = beta;
newalpha = alpha;
if (HashTable2[index].key == Zkey)
{
if (HashTable2[index].depth >= (depth + extension))
{
if (HashTable2[index].flag == HASHEXACT)
{
hvalue = HashTable2[index].value_Renamed;
}
if (HashTable2[index].flag == HASHALPHA && HashTable2[index].value_Renamed <= alpha)
{
hvalue = alpha;
}
if (HashTable2[index].flag == HASHALPHA && HashTable2[index].value_Renamed < beta)
{
newbeta = HashTable2[index].value_Renamed;
}
if (HashTable2[index].flag == HASHBETA && HashTable2[index].value_Renamed >= beta)
{
hvalue = beta;
}
if (HashTable2[index].flag == HASHBETA && HashTable2[index].value_Renamed > alpha)
{
newalpha = HashTable2[index].value_Renamed;
}
}
bestMove = HashTable2[index].move;
}
if (HashTable1[index].key == Zkey)
{
if (HashTable1[index].depth >= (depth + extension))
{
if (HashTable1[index].flag == HASHEXACT)
{
hvalue = HashTable1[index].value_Renamed;
}
if (HashTable1[index].flag == HASHALPHA && HashTable1[index].value_Renamed <= alpha)
{
hvalue = alpha;
}
if (HashTable1[index].flag == HASHALPHA && HashTable1[index].value_Renamed < beta)
{
newbeta = HashTable1[index].value_Renamed;
}
if (HashTable1[index].flag == HASHBETA && HashTable1[index].value_Renamed >= beta)
{
hvalue = beta;
}
if (HashTable1[index].flag == HASHBETA && HashTable1[index].value_Renamed > alpha)
{
newalpha = HashTable1[index].value_Renamed;
}
}
bestMove = HashTable1[index].move;
}
if (HashTable3[index].key == Zkey)
{
hvalue = HashTable3[index].value_Renamed;
}
beta = newbeta;
alpha = newalpha;
if (hvalue != -1)
{
pv.length = 0;
return hvalue;
}
MoveList mypv = new MoveList();
//entschiedene Positionen
if (p.isWon(!p.toMove, move))
{
pv.length = 0;
addHashEntries(Zkey, index, depth + extension, -1000 + p.numberOfDiscs(), HASHEXACT, -1);
return -1000 + p.numberOfDiscs();
}
if (p.Draw)
{
pv.length = 0;
addHashEntries(Zkey, index, depth + extension, 0, HASHEXACT, -1);
return 0;
}
//Eröffnungsbuchzugriff
if (opening)
{
if (p.numberOfDiscs() <= 8)
{
value_Renamed = searchBook(p);
if (value_Renamed != -1)
{
pv.length = 0;
addHashEntries(Zkey, index, depth + extension, value_Renamed, HASHEXACT, -1);
return value_Renamed;
}
}
}
//Interior Node Recognition
firstFreeColumn = -1;
secondFreeColumn = -1;
freeColumns = 0;
for (int i = 0; i < 7; i++)
{
if (p.height[i] != 6)
{
freeColumns += 1;
if (freeColumns == 3)
break;
if (freeColumns == 1)
firstFreeColumn = i;
if (freeColumns == 2)
secondFreeColumn = i;
}
}
//Wenn nur mehr wenige Spalten frei sind (Ende des Spieles)
if (freeColumns == 1 || (freeColumns == 2 && (secondFreeColumn - firstFreeColumn >= 4)))
{
if (acuteThreat(p, p.toMove) == -1 && acuteThreat(p, !p.toMove) == -1)
{
value_Renamed = evaluate(p, true);
pv.length = 0;
addHashEntries(Zkey, index, depth + extension, value_Renamed, HASHEXACT, -1);
return value_Renamed;
}
}
if (depth <= (0 - extension))
{
int akut2 = acuteThreat(p, p.toMove);
if (akut2 != -1)
{
pv.length = 0;
addHashEntries(Zkey, index, depth + extension, 1000 - p.numberOfDiscs() - 1, HASHEXACT, -1);
return 1000 - p.numberOfDiscs() - 1;
}
int akut = acuteThreat(p, !p.toMove);
if (akut == -1)
{
pv.length = 0;
int val = evaluate(p, false);
addHashEntries(Zkey, index, depth + extension, val, HASHEXACT, -1);
return val;
}
extension += 2;
Zkey = Zkey ^ (p.toMove ? zobristKeys[akut][0] : zobristKeys[akut][1]);
int value_Renamed = -AlphaBeta(p, depth - 1, -beta, -alpha, extension, mypv, Zkey, akut);
p.undoMove(akut);
Zkey = Zkey ^ (p.toMove ? zobristKeys[akut][0] : zobristKeys[akut][1]);
if (value_Renamed >= beta)
{
addHashEntries(Zkey, index, depth + extension - 2, beta, HASHBETA, -1);
return beta;
}
if (value_Renamed > alpha)
{
hashflag = HASHEXACT;
alpha = value_Renamed;
pv.First = new MoveListElement(akut);
if (mypv.length != 0)
{
pv.Rest = mypv;
}
pv.length = mypv.length + 1;
}
addHashEntries(Zkey, index, depth + extension - 2, alpha, hashflag, -1);
return alpha;
}
int[] moves = generateMoves(p, searchDepth - depth);
sort(moves, p); //Sortiert Züge nach Feldgewichten und nach dem besten Zug aus den Hash Tables
//Suchvertiefung
for (int i = 0; i < moves[7]; i++)
{
Zkey = Zkey ^ (p.toMove ? zobristKeys[moves[i]][0] : zobristKeys[moves[i]][1]);
value_Renamed = -AlphaBeta(p, depth - 1, -beta, -alpha, extension, mypv, Zkey, moves[i]);
p.undoMove(moves[i]);
Zkey = Zkey ^ (p.toMove ? zobristKeys[moves[i]][0] : zobristKeys[moves[i]][1]);
if (value_Renamed >= beta)
{
addHashEntries(Zkey, index, depth + extension, value_Renamed, HASHBETA, moves[i]);
return beta;
}
if (value_Renamed > alpha)
{
hashflag = HASHEXACT;
alpha = value_Renamed;
pv.First = new MoveListElement(moves[i]);
if (mypv.length != 0)
{
pv.Rest = mypv;
}
pv.length = mypv.length + 1;
}
}
addHashEntries(Zkey, index, depth + extension, alpha, hashflag, (hashflag == HASHEXACT ? pv.pop() : -1));
return alpha;
}
/*
* nur in Situationen anwendbar, in denen niemand gewonnen hat und kein unentschieden vorliegt
*/
private int evaluate(Position p, bool recognized)
{
if (recognized)
{
counterrecognized += 1;
}
else
{
counterevaluated += 1;
}
//Threats ermitteln
getthreats(p, Position.WHITE);
getthreats(p, Position.BLACK);
//Array initialisieren
int[] height = new int[7];
int totalheight = 0;
for (int i = 0; i < 7; i++)
{
height[i] = 6;
for (int j = 0; j < 6; j++)
{
if (blackthreats[i][j] || whitethreats[i][j])
{
height[i] = p.height[i];
totalheight += height[i];
goto outer;
}
}
totalheight += 6;
outer: ;
}
if (totalheight == 42)
{
return 0;
}
//Gewinner feststellen, falls auf restlichem Brett nichts passiert
bool toMove = (totalheight % 2 == 0) ? Position.WHITE : Position.BLACK;
bool winner;
bool found = true;
while (found)
{
found = false;
//eigenen Threat besetzen
for (int i = 0; i < 7; i++)
{
if (height[i] < 6 && (toMove == Position.WHITE ? whitethreats[i][height[i]] : blackthreats[i][height[i]]))
{
winner = toMove;
if (recognized)
{
return (p.toMove == winner) ? (699 - totalheight) : (-699 + totalheight);
}
else
{
return (p.toMove == winner) ? (458 + p.numberOfDiscs()) : (-458 - p.numberOfDiscs());
}
}
}
//gegnerischen Threat besetzen
for (int i = 0; i < 7; i++)
{
if (height[i] < 6 && (toMove == Position.WHITE ? blackthreats[i][height[i]] : whitethreats[i][height[i]]))
{
height[i] += 1;
toMove = !toMove;
found = true;
//UPGRADE_NOTE: Die continue-Anweisung mit Bezeichnung wurde in eine goto-Anweisung geändert. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1015'"
goto outer1;
}
}
//unkritisches Feld besetzen
for (int i = 0; i < 7; i++)
{
if ((height[i] == 5) || (height[i] < 5 && !blackthreats[i][height[i] + 1] && !whitethreats[i][height[i] + 1]))
{
height[i] += 1;
toMove = !toMove;
found = true;
//UPGRADE_NOTE: Die continue-Anweisung mit Bezeichnung wurde in eine goto-Anweisung geändert. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1015'"
goto outer1;
}
}
//unter eigene Drohung ziehen, ungerade Anzahl freier Felder
for (int i = 0; i < 7; i++)
{
if (height[i] < 5 && (toMove == Position.WHITE ? !blackthreats[i][height[i] + 1] : !whitethreats[i][height[i] + 1]) && ((6 - height[i]) % 2 == 1))
{
height[i] += 1;
toMove = !toMove;
found = true;
//UPGRADE_NOTE: Die continue-Anweisung mit Bezeichnung wurde in eine goto-Anweisung geändert. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1015'"
goto outer1;
}
}
//unter eigene Drohung ziehen, gerade Anzahl freier Felder
for (int i = 0; i < 7; i++)
{
if (height[i] < 5 && (toMove == Position.WHITE ? !blackthreats[i][height[i] + 1] : !whitethreats[i][height[i] + 1]))
{
height[i] += 1;
toMove = !toMove;
found = true;
//UPGRADE_NOTE: Die continue-Anweisung mit Bezeichnung wurde in eine goto-Anweisung geändert. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1015'"
goto outer1;
}
}
//unter gegnerische Drohung ziehen
for (int i = 0; i < 7; i++)
{
if (height[i] < 5)
{
height[i] += 1;
toMove = !toMove;
found = true;
//UPGRADE_NOTE: Die continue-Anweisung mit Bezeichnung wurde in eine goto-Anweisung geändert. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1015'"
goto outer1;
}
}
goto outer1_brk;
outer1: ;
}
outer1_brk: ;
return 0;
}
/*
*
* Hauptmethode des Computerspielers, die eine Position annimmt und einen Zug zurückgibt.
* Sie kapselt den Alpha-Beta-Algorithmus.
*/
public override int returnMove(Position arg)
{
//Spielfeld übernehmen
Position p = new Position(arg);
//Startwerte für das Iterative Deepening
nodecount[1] = savedSum;
int lastRoundMove = -1;
int lastRoundValue = -1000;
int bestFoundValue = 0; // Bewertung des besten Zuges
searchDepth = 1; //aktuelle Suchtiefe
int alpha = -10000;
int beta = 10000;
MoveList pv = new MoveList();
bool repeated = false;
//Zobrist-Key erstellen
long Zkey = 0;
for (int i = 0; i < 42; i++)
{
if ((p.whiteDiscs & (0x0000000000400000L << i)) == (0x0000000000400000L << i))
{
Zkey = Zkey ^ zobristKeys[i][0]; //^ = XOR
}
else if ((p.blackDiscs & (0x0000000000400000L << i)) == (0x0000000000400000L << i))
{
Zkey = Zkey ^ zobristKeys[i][1];
}
}
//Löschen der HashTables 1 und 2.
for (int i = 0; i < HASHSIZE; i++)
{
HashTable1[i].clear();
HashTable2[i].clear();
}
//feststellen, ob man sich noch in der Eröffnung befindet
if (bookEnabled && p.numberOfDiscs() < 8)
{
opening = true;
}
else
{
opening = false;
}
//Iterative-Deepening-Schleife
while (!(searchDepth > (42 - p.numberOfDiscs())))
{
repeated = false;
nodecount[0] = 0;
maxDepth = 100;
counterrecognized = 0;
counterevaluated = 0;
counterhash1 = 0;
counterhash2 = 0;
counterhash3 = 0;
pv = new MoveList(); //Zugliste
long startTime = 0;
long duration = 0;
try
{
//Aspiration Search verlangt ggf. mehrere Anläufe
while (true)
{
startTime = (System.DateTime.Now.Ticks - 621355968000000000) / 10000;
bestFoundValue = StartAlphaBeta(p, searchDepth, alpha, beta, 0, pv, Zkey); //Aufruf des eigentlichen Algorithmusses
duration = repeated ? duration + (System.DateTime.Now.Ticks - 621355968000000000) / 10000 - startTime : (System.DateTime.Now.Ticks - 621355968000000000) / 10000 - startTime;
//Start Aspiration Windows
if (bestFoundValue <= alpha && !repeated) //erweitern des Suchfenster nach unten
{
repeated = true;
alpha = -10000;
beta = bestFoundValue + 2;
continue;
}
if (bestFoundValue >= beta && !repeated) //erweitern des Suchfensters nach oben
{
repeated = true;
beta = 10000;
alpha = bestFoundValue - 2;
continue;
}
if (repeated && (bestFoundValue <= alpha || bestFoundValue >= beta)) //setzen des Suchfensters auf Startwerte
{
alpha = -10000;
beta = 10000;
continue;
}
if (bestFoundValue == 0) //Unentschieden oder Ungeklärte Situation
{
alpha = bestFoundValue - 2;
beta = bestFoundValue + 2;
}
if (bestFoundValue > 0 && bestFoundValue < 600) //alles offen
{
alpha = bestFoundValue;
beta = bestFoundValue + 2;
}
if (bestFoundValue < 0 && bestFoundValue > -600) //alles offen für anderen Spieler
{
alpha = bestFoundValue - 2;
beta = bestFoundValue;
}
if (bestFoundValue > 600) //sicher gewonnen
{
alpha = bestFoundValue - 1;
beta = bestFoundValue + 1;
}
if (bestFoundValue < -600) //sicher gewonnen für anderen Spieler
{
alpha = bestFoundValue - 1;
beta = bestFoundValue + 1;
}
//Ende Aspiration Windows
break;
}
}
catch (TooManyNodesException) //max. Anzahl von Knoten überschritten
{
duration = repeated ? duration + (System.DateTime.Now.Ticks - 621355968000000000) / 10000 - startTime : (System.DateTime.Now.Ticks - 621355968000000000) / 10000 - startTime;
totalDuration = totalDuration + duration;
nodecount[2] = nodecount[2] + nodecount[0];
nodecount[1] = nodecount[1] + nodecount[0];
return lastRoundMove;
}
lastRoundMove = pv.pop();
lastRoundValue = bestFoundValue;
totalDuration = totalDuration + duration;
nodecount[2] = nodecount[2] + nodecount[0];
nodecount[1] = nodecount[1] + nodecount[0];
int overwritten1 = 0;
int overwritten2 = 0;
int overwritten3 = 0;
for (int i = 0; i < HASHSIZE; i++)
{
if (HashTable1[i].depth != -1)
{
counterhash1 += 1; overwritten1 += HashTable1[i].overwritten;
}
if (HashTable2[i].depth != -1)
{
counterhash2 += 1; overwritten2 += HashTable2[i].overwritten;
}
if (HashTable3[i].depth != -1)
{
counterhash3 += 1; overwritten3 += HashTable3[i].overwritten;
}
}
if (bestFoundValue > 900 || bestFoundValue < -900)
{
break;
}
searchDepth += 1;
}
if (bestFoundValue < -900)
{
if (!opening)
{
return lastRoundMove;
}
else
{
//Wenn man in der Eröffnung in einer verlorenen Position ist, löscht man die Hash Tables und sucht ohne Eröffnungsbuch von vorne.
bookEnabled = false;
savedSum = nodecount[1];
for (int i = 0; i < HASHSIZE; i++)
{
HashTable3[i].clear();
}
int result = returnMove(p);
for (int i = 0; i < HASHSIZE; i++)
{
HashTable3[i].clear();
}
savedSum = 0;
bookEnabled = true;
return result;
}
}
else
{
return lastRoundMove;
}
}