What's wrong with this alpha-beta function?
1.allGMoves is a bitboard that keeps all the position currently occupied by the genius pieces
2.allMMoves the same thing but with the MINIME moves(human player)
3.I haven't done the Evaluate() function,it just returns 0
4.INFINITY 100
[SOURCE]
int CGameTree::AlphaBeta(int depth, int alpha, int beta,int turn)
{
unsigned __int64 lastMove;
int val=0;
if(depth==0) return Evaluate();
GenerateLegalMoves(turn);/*this fills the stack with all the possible moves*/
if(turn==GENIUS)
{
for(int i=0;i<16;i++)
{
for(int j=0;j<stack.size();j++)
{
lastMove=pList;//save current move
pList.at(i)->move=stack[j];//Do move
allGMoves^=lastMove;//erase current position occupied by this piece on the global genius board
allGMoves^=stack[j];//write new occupied position
val=-AlphaBeta(depth-1,-beta,-alpha,(turn+1)%2);
if(val>=beta)return beta;//cutoff
if(val>alpha)alpha=val;
if((val<alpha && depth==MAX_LEVEL)||depth!=MAX_LEVEL)
{
allGMoves^=stack[j];//undo move
allGMoves^=lastMove;
pList.at(i)->move=lastMove;
}
}
}
return alpha;
}else if(turn==MINIME)
{
for(int i=16;i<31;i++)
{
for(int j=0;j<stack.size();j++)
{
lastMove=pList;//save current move
pList.at(i)->move=stack[j];//Do move
allGMoves^=lastMove;//erase position occupied by this move
allGMoves^=stack[j];//write new occupied position
val=-AlphaBeta(depth-1,-beta,-alpha,(turn+1)%2);
if(val>=beta)return beta;//cutoff
if(val>alpha)alpha=val;
allGMoves^=stack[j];//undo move
allGMoves^=lastMove;
pList.at(i)->move=lastMove;
}
}
return alpha;
}
}
[/SOURCE]
[/source][/source][/source]
Thanks for the great effort of reading this long function!
I guess the doing and undoing is wrong
Do you know a way of doing and undoing moves....PLeeeease!
[Edited by - Hermes on October 27, 2004 9:52:59 AM]
