backgammon.c

早期freebsd实现

int *mover,*movee;
{
	int	k;

	for(i = 0; i <= 24; i++){
		count = 0;
		if(mover[i] == 0)
			continue;
		if((k=25-i-die1) > 0 && movee[k] >= 2)
			if(mover[0] > 0)
				break;
		else
			continue;
		if(k <= 0){
			if(piececount(mover, 0, 18) != 0)
				break;
			if((i+die1) != 25 && piececount(mover,19,i-1) != 0)
				break;
		}
		mover[i]--;
		mover[i+die1]++;
		count = 1;
		for(j = 0; j <= 24; j++){
			if(mover[j]==0)
				continue;
			if((k=25-j-die2) > 0 && movee[k] >= 2)
				if(mover[0] > 0)
					break;
			else
				continue;
			if(k <= 0){
				if(piececount(mover,0,18) != 0)
					break;
				if((j+die2) != 25 && piececount(mover,19,j-1) != 0)
					break;
			}
			mover[j]--;
			mover[j+die2]++;
			count = 2;
			if(die1 != die2){
				moverecord(mover);
				if(mover[0] > 0)
					break;
				else
					continue;
			}
			for(l = 0; l <= 24; l++){
				if(mover[l] == 0)
					continue;
				if((k=25-l-die1) > 0 && movee[k] >= 2)
					if(mover[0] > 0)
						break;
				else
					continue;
				if(k <= 0){
					if(piececount(mover, 0, 18) != 0)
						break;
					if((l+die2) != 25 && piececount(mover,19,l-1) != 0)
						break;
				}
				mover[l]--;
				mover[l+die1]++;
				count=3;
				for(m=0;m<=24;m++){
					if(mover[m]==0)
						continue;
					if((k=25-m-die1) >= 0 && movee[k] >= 2)
						if(mover[0] > 0)
							break;
					else
						continue;
					if(k <= 0){
						if(piececount(mover,0,18) != 0)
							break;
						if((m+die2) != 25 && piececount(mover,19,m-1) != 0)
							break;
					}
					count=4;
					moverecord(mover);
					if(mover[0] > 0)
						break;
				}
				if(count == 3)
					moverecord(mover);
				else{
					mover[l]++;
					mover[l+die1]--;
				}
				if(mover[0] > 0)
					break;
			}
			if(count == 2)
				moverecord(mover);
			else{
				mover[j]++;
				mover[j+die1]--;
			}
			if(mover[0] > 0)
				break;
		}
		if(count == 1)
			moverecord(mover);
		else{
			mover[i]++;
			mover[i+die1]--;
		}
		if(mover[0] > 0)
			break;
	}
}
moverecord(mover)
int *mover;
{
	int	t;

	if(imoves < MAXIMOVES) {
		for(t = 0; t <= 3; t++)
			moves[imoves].pos[t] = NIL;
		switch(count) {
		case 4:
			moves[imoves].pos[3]=m;
			moves[imoves].mov[3]=die1;

		case 3:
			moves[imoves].pos[2]=l;
			moves[imoves].mov[2]=die1;

		case 2:
			moves[imoves].pos[1]=j;
			moves[imoves].mov[1]=die2;

		case 1:
			moves[imoves].pos[0]=i;
			moves[imoves].mov[0]=die1;
			imoves++;
		}
	}
	switch(count) {
	case 4:
		break;

	case 3:
		mover[l]++;
		mover[l+die1]--;
		break;

	case 2:
		mover[j]++;
		mover[j+die2]--;
		break;

	case 1:
		mover[i]++;
		mover[i+die1]--;
	}
}

strategy(player,playee)
int *player,*playee;
{
	int	k, n, nn, bestval, moveval, prob;

	n = 0;
	if(imoves == 0)
		return(NIL);
	goodmoves[0] = NIL;
	bestval = -32000;
	for(k = 0; k < imoves; k++){
		if((moveval=eval(player,playee,k,&prob)) < bestval)
			continue;
		if(moveval > bestval){
			bestval = moveval;
			n = 0;
		}
		if(n<MAXGMOV){
			goodmoves[n]=k;
			probmoves[n++]=prob;
		}
	}
	if(level=='e' && n>1){
		nn=n;
		n=0;
		prob=32000;
		for(k = 0; k < nn; k++){
			if((moveval=probmoves[k]) > prob)
				continue;
			if(moveval<prob){
				prob=moveval;
				n=0;
			}
			goodmoves[n]=goodmoves[k];
			probmoves[n++]=probmoves[k];
		}
	}
	return(goodmoves[(rand()>>4)%n]);
}

eval(player,playee,k,prob)
int *player,*playee,k,*prob;
{
	int	newtry[31], newother[31], *r, *q, *p, n, sum, first;
	int	ii, lastwhite, lastbrown;

	*prob = sum = 0;
	r = player+25;
	p = newtry;
	q = newother;
	while(player<r){
		*p++= *player++;
		*q++= *playee++;
	}
	q=newtry+31;
	for(p = newtry+25; p < q; p++)		/* zero out spaces for hit pieces */
		*p = 0;
	for(n = 0; n < 4; n++){
		if(moves[k].pos[n] == NIL)
			break;
		newtry[moves[k].pos[n]]--;
		newtry[ii=moves[k].pos[n]+moves[k].mov[n]]++;
		if(ii<25 && newother[25-ii]==1){
			newother[25-ii]=0;
			newother[0]++;
			if(ii<=15 && level=='e')		/* hit if near other's home */
				sum++;
		}
	}
	for(lastbrown = 0; newother[lastbrown] == 0; lastbrown++);
		;
	for(lastwhite = 0; newtry[lastwhite] == 0; lastwhite++)
		;
	lastwhite = 25-lastwhite;
	if(lastwhite<=6 && lastwhite<lastbrown)
		sum=1000;
									/* experts running game. */
									/* first priority is to */
									/* get all pieces into */
									/* white's home */
	if(lastwhite<lastbrown && level=='e' && lastwhite>6) {
		for(sum = 1000; lastwhite > 6; lastwhite--)
			sum = sum-lastwhite*newtry[25-lastwhite];
	}
	for(first = 0; first < 25; first++)
		if(newother[first] != 0)		/*find other's first piece*/
			break;
	q = newtry+25;
	for(p = newtry+1; p < q;)			/* blocked points are good */
		if(*p++ > 1)
			sum++;
	if(first > 5) {					/* only stress removing pieces if */
							/* homeboard cannot be hit */
		q = newtry+31;
		p=newtry+25;
		for(n = 6; p < q; n--)
			sum += *p++ * n;			/*remove pieces, but just barely*/
	}
	if(level != 'b'){
		r = newtry+25-first;	/*singles past this point can't be hit*/
		for(p = newtry+7; p < r; )
			if(*p++ == 1)		/*singles are bad after 1st 6 points if they can be hit*/
				sum--;
		q = newtry+3;
		for(p = newtry; p < q; )	   /*bad to be on 1st three points*/
			sum -= *p++;
	}

	for(n = 1; n <= 4; n++)
		*prob += n*getprob(newtry,newother,6*n-5,6*n);
	return(sum);
}
instructions()
{
	register fd, r;
	char	 buf[BUFSIZ];

	if((fd = open(RULES, 0)) < 0) {
		fprintf(stderr, "back: cannot open %s\n", RULES);
		return;
	}
	while(r = read(fd, buf, BUFSIZ))
		write(1, buf, r);
}

getprob(player,playee,start,finish)
int *player,*playee,start,finish;
{			/*returns the probability (times 102) that any
			  pieces belonging to 'player' and lying between
			  his points 'start' and 'finish' will be hit
			  by a piece belonging to playee
			*/
	int	k, n, sum;

	sum = 0;
	for(; start <= finish; start++){
		if(player[start] == 1){
			for(k = 1; k <= 12; k++){
				if((n=25-start-k) < 0)
					break;
				if(playee[n] != 0)
					sum += probability[k];
			}
		}
	}
	return(sum);
}
prtbrd()
{
	int	k;
	static char undersc[]="______________________________________________________";

	fprintf(stdout, "White's Home\n%s\r",undersc);
	for(k = 1; k <= 6; k++)
		fprintf(stdout, "%4d",k);
	fprintf(stdout, "    ");
	for(k = 7; k <= 12; k++)
		fprintf(stdout, "%4d",k); 
	putchar('\n');
	numline(brown, white, 1, 6);
	fprintf(stdout, "    ");
	numline(brown, white, 7, 12);
	putchar('\n');
	colorline(brown, 'B', white, 'W', 1, 6);
	fprintf(stdout, "    ");
	colorline(brown, 'B', white, 'W', 7, 12);
	putchar('\n');
	if(white[0] != 0)
		fprintf(stdout, "%28dW\n",white[0]);
	else
		putchar('\n');
	if(brown[0] != 0)
		fprintf(stdout, "%28dB\n", brown[0]);
	else
		putchar('\n');
	colorline(white, 'W', brown, 'B', 1, 6);
	fprintf(stdout, "    ");
	colorline(white, 'W', brown, 'B', 7, 12);
	fprintf(stdout, "\n%s\r",undersc);
	numline(white, brown, 1, 6);
	fprintf(stdout, "    ");
	numline(white, brown, 7, 12);
	putchar('\n');
	for(k = 24; k >= 19; k--)
		fprintf(stdout, "%4d",k);
	fprintf(stdout, "    ");
	for(k = 18; k >= 13; k--)
		fprintf(stdout, "%4d",k);
	fprintf(stdout, "\nBrown's Home\n\n\n\n\n");
}
numline(upcol,downcol,start,fin)
int *upcol,*downcol,start,fin;
{
	int	k, n;

	for(k = start; k <= fin; k++){
		if((n = upcol[k]) != 0 || (n = downcol[25-k]) != 0)
			fprintf(stdout, "%4d", n);
		else
			fprintf(stdout, "    ");
	}
}
colorline(upcol,c1,downcol,c2,start,fin)
int *upcol,*downcol,start,fin;
char c1,c2;
{
	int	k;
	char 	c;

	for(k = start; k <= fin; k++){
		c = ' ';
		if(upcol[k] != 0)
			c = c1;
		if(downcol[25-k] != 0)
			c = c2;
		fprintf(stdout, "   %c",c);
	}
}