V7M/src/games/backgammon.c
# include <stdio.h>
#
#define NIL (-1)
#define MAXGMOV 10
#define MAXIMOVES 1000
char level; /*'b'=beginner, 'i'=intermediate, 'e'=expert*/
int die1;
int die2;
int i;
int j;
int l;
int m;
int count;
int red[] {0,2,0,0,0,0,0,0,0,0,0,0,5,
0,0,0,0,3,0,5,0,0,0,0,0,
0,0,0,0,0,0};
int white[] {0,2,0,0,0,0,0,0,0,0,0,0,5,
0,0,0,0,3,0,5,0,0,0,0,0,
0,0,0,0,0,0};
int probability[]{0,11,12,13,14,15,16,
06,05,04,03,02,01};
int imoves;
int goodmoves[MAXGMOV] ;
int probmoves[MAXGMOV] ;
struct {int pos[4],mov[4];} moves[MAXIMOVES] ;
main()
{
int t,k,n,go[5];
char s[100];
go[5]=NIL;
srand();
printf( "Do you want instructions? Type 'y' for yes,\n");
printf( "anything else means no.?? ");
getstr(s);
if(*s=='y')instructions();
printf( "Choose the level of your oppponent.\n");
printf( "Type 'b' for beginner, or 'i' for intermediate.\n");
printf( "Anything else gets you an expert.?? ");
level='e';
getstr(s);
if(*s=='b')level='b';
else if(*s=='i')level='i';
printf( "You will play red. Do you wan't to move first?\n");
printf( "Type 'y' for yes, anything else means no.?? ");
getstr(s);
if(*s=='y')goto nowhmove;
whitesmv:
roll();
printf( "white rolls %d,%d\n",die1,die2);
printf( "white's move is:");
if(nextmove(white,red)==NIL)goto nowhmove;
if(piececount(white,0,24)==0){
printf( "White wins\n");
printf( "Aren't you ashamed. You've been beaten by a computer.\n");
exit();
}
nowhmove:
prtbrd();
roll();
retry:
printf( "your roll is %d, %d\n",die1,die2);
printf( "your move, please?? ");
getstr(s);
if(*s==0){
printf( "red's move skipped\n");
goto whitesmv;
}
n=sscanf(s,"%d%d%d%d%d",&go[0],&go[1],&go[2],&go[3],&go[4]);
if((die1!=die2&&n>2)||n>4){
printf( "you've made too many moves\n");
goto retry;
}
go[n]=NIL;
if(*s=='-'){
go[0]= -go[0];
t=die1;
die1=die2;
die2=t;
}
for(k=0;k<n;k++){
if(0<=go[k] && go[k]<=24)continue;
else{
printf( "move %d is illegal\n",go[k]);
goto retry;
}
}
if(play(red,white,go))goto retry;
if(piececount(red,0,24)==0){
printf( "Red wins.\n");
printf( "Congratulations! You have just defeated a dumb machine.\n");
exit();
}
goto whitesmv;
}
getstr(s)
char *s;
{
while((*s=getchar())!='\n')s++;
*s=0;
}
play(player,playee,pos)
int *player,*playee,pos[];
{
int k,n,die,ipos;
for(k=0;k<player[0];k++){ /*blots on player[0] must be moved first*/
if(pos[k]==NIL)break;
if(pos[k]!=0){
printf( "piece on position 0 must be moved first\n");
return(-1);
}
}
for(k=0;(ipos=pos[k])!=NIL;k++){
die=k?die2:die1;
n=25-ipos-die;
if(player[ipos]==0)goto badmove;
if(n>0&&playee[n]>=2)goto badmove;
if(n<=0){
if(piececount(player,0,18)!=0)goto badmove;
if((ipos+die)!=25&&
piececount(player,19,24-die)!=0)goto badmove;
}
player[ipos]--;
player[ipos+die]++;
}
for(k=0;pos[k]!=NIL;k++){
die=k?die2:die1;
n=25-pos[k]-die;
if(n>0 && playee[n]==1){
playee[n]=0;
playee[0]++;
}
}
return(0);
badmove:
printf( "Move %d is not legal.\n",ipos);
while(k--){
die=k?die2:die1;
player[pos[k]]++;
player[pos[k]+die]--;
}
return(-1);
}
nextmove(player,playee)
int *player,*playee;
{
int k;
imoves=0;
movegen(player,playee);
if(die1!=die2){
k=die1;
die1=die2;
die2=k;
movegen(player,playee);
}
if(imoves==0){
printf( "roll was %d,%d; no white move possible\n",die1,die2);
return(NIL);
}
k=strategy(player,playee); /*select kth possible move*/
prtmov(k);
update(player,playee,k);
return(0);
}
prtmov(k)
int k;
{
int n;
if(k==NIL)printf( "no move possible\n");
else for(n=0;n<4;n++){
if(moves[k].pos[n]==NIL)break;
printf( " %d, %d",25-moves[k].pos[n],moves[k].mov[n]);
}
printf( "\n");
}
update(player,playee,k)
int *player,*playee,k;
{
int n,t;
for(n=0;n<4;n++){
if(moves[k].pos[n]==NIL)break;
player[moves[k].pos[n]]--;
player[moves[k].pos[n]+moves[k].mov[n]]++;
t=25-moves[k].pos[n]-moves[k].mov[n];
if(t>0 && playee[t]==1){
playee[0]++;
playee[t]--;
}
}
}
piececount(player,startrow,endrow)
int *player,startrow,endrow;
{
int sum;
sum=0;
while(startrow<=endrow)
sum=+player[startrow++];
return(sum);
}
/*
prtmovs()
{
int i1,i2;
printf( "possible moves are\n");
for(i1=0;i1<imoves;i1++){
printf( "\n%d",i1);
for(i2=0;i2<4;i2++){
if(moves[i1].pos[i2]==NIL)break;
printf( "%d, %d",moves[i1].pos[i2],moves[i1].mov[i2]);
}
}
printf( "\n");
}
*/
roll()
{
extern int die1,die2;
die1=(rand()>>8)%6+1;
die2=(rand()>>8)%6+1;
}
movegen(mover,movee)
int *mover,*movee;
{
extern int i,j,l,m,count;
extern int die1,die2;
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,19,24-die1)!=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,19,24-die2)!=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,19,24-die1)!=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,19,24-die1)!=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;
{
extern int i,j,l,m,imoves,count;
int t;
if(imoves>=MAXIMOVES)goto undo;;
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++;
}
undo:
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;
{
extern char level;
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;
{
extern char level;
int newtry[31],newother[31],*r,*q,*p,n,sum,first;
int ii,lastwhite,lastred;
*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++ = 0; /*zero out spaces for hit pieces*/
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')sum++; /*hit if near other's home*/
}
}
for(lastred=0;newother[lastred]==0;lastred++);
for(lastwhite=0;newtry[lastwhite]==0;lastwhite++);
lastwhite=25-lastwhite;
if(lastwhite<=6 && lastwhite<lastred)sum=1000;
if(lastwhite<lastred && level=='e'
&& lastwhite>6){ /*expert's running game.
First priority to get all
pieces into white's home*/
for(sum=1000;lastwhite>6;lastwhite--)
sum=sum-lastwhite*newtry[25-lastwhite];
}
for(first=0;first<25;first++)
if(newother[first]!=0)break; /*find other's first piece*/
q=newtry+25;
for(p=newtry+1;p<q;)if(*p++ > 1)sum++; /*blocked points are good*/
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)sum--; /*singles are bad after 1st 6 points
if they can be hit*/
q=newtry+3;
for(p=newtry;p<q;)sum=- *p++; /*bad to be on 1st three points*/
}
for(n=1;n<=4;n++)
*prob=+ n*getprob(newtry,newother,6*n-5,6*n);
return(sum);
}
instructions()
{
printf( "To play backgammon, type the numbers of the points\n");
printf( "from which pieces are to be moved. Thus, if the\n");
printf( "roll is '3,5', typing '2 6' will move a piece\n");
printf( "from point 2 three spaces to point 5,\n");
printf( "and a piece from point 6 forward to\n");
printf( "point 11. If the moves must be made in the\n");
printf( "opposite order, the first character typed must\n");
printf( "be a minus ('-'). Thus, typing\n");
printf( "'-2 6' moves the piece on point 2\n");
printf( "by 5, and the piece on point 6 by 3.\n");
printf( "If you want to move a single piece several times,\n");
printf( "the sequence of points from which it is to be\n");
printf( "moved must be typed. Thus '14 17' will move\n");
printf( "a piece from point 14 to point 17 and thence to\n");
printf( "to point 22.\n");
printf( "If a double is rolled, you should type four numbers.\n");
printf( "Red pieces that have been removed from the board by\n");
printf( "being hit by white are on point 0 and\n");
printf( "must be brought in before any other move can be made.\n");
printf( "White pieces that are hit are removed to point 25.\n");
printf( "You will not be allowed to make an illegal move, or\n");
printf( "to make too many moves. However, if you make too\n");
printf( "few moves, the program does not care. In particular\n");
printf( "you may skip your turn by typing a 'new-line'\n");
printf( "all by itself.\n\n");
}
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;
printf( "White's Home\n");
for(k=1;k<=6;k++)
printf( "%4d",k);
printf( " ");
for(k=7;k<=12;k++)printf( "%4d",k);
putchar('\r' );
for(k=1;k<=54;k++)putchar('_' );
putchar('\n' );
numline(red,white,1,6);
printf( " ");
numline(red,white,7,12);
putchar('\n' );
colorline(red,'R',white,'W',1,6);
printf( " ");
colorline(red,'R',white,'W',7,12);
putchar('\n' );
if(white[0]!=0)printf( "%28dW\n",white[0]);
else putchar('\n' );
if(red[0]!=0)printf( "%28dR\n",red[0]);
else putchar('\n' );
colorline(white,'W',red,'R',1,6);
printf( " ");
colorline(white,'W',red,'R',7,12);
putchar('\n' );
numline(white,red,1,6);
printf( " ");
numline(white,red,7,12);
putchar('\r' );
for(k=1;k<=54;k++)putchar('_' );
putchar('\n' );
for(k=24;k>=19;k--)printf( "%4d",k);
printf( " ");
for(k=18;k>=13;k--)printf( "%4d",k);
printf( "\nRed'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)printf( "%4d",n);
else printf( " ");
}
}
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;
printf( " %c",c);
}
}
int rrno 0;
srand(){
rrno = _look( 0x40000 );
_store( 0x40000, rrno+1 );
}
rand(){
rrno =* 0106273;
rrno =+ 020202;
return( rrno & 077777 );
}
_look(p) int *p; {
return( *p );
}
_store( p, numb ) int *p; {
*p = numb;
}