changed some chars into signed chars...
Code: Select all
/***************************************************************************/
/* micro-Max, */
/* A chess program smaller than 2KB (of non-blank source), by H.G. Muller */
/***************************************************************************/
/* version 4.8.n Sketch (1953 characters) features: */
/* - recursive negamax search */
/* - all-capture MVV/LVA quiescence search */
/* - (internal) iterative deepening */
/* - best-move-first 'sorting' */
/* - a hash table storing score and best move */
/* - futility pruning */
/* - king safety through magnetic, frozen king in middle-game */
/* - R=2 null-move pruning */
/* - keep hash and repetition-draw detection */
/* - better defense against passers through gradual promotion */
/* - extend check evasions in inner nodes */
/* - reduction of all non-Pawn, non-capture moves except hash move (LMR) */
/* - full FIDE rules (expt under-promotion) and move-legality checking */
#define K(A,B) *(int*)(T+A+(B&8)+S*(B&7))
#define HTsize (1<<12) // wegen RAM, für PC: (1<<24)
struct HTab {
int K,
V;
int X,
Y,
D;
} HTarray[HTsize]; /* hash table, HTsize entries*/
#define MAXNODES 80000 // wegen Zugdauer; für PC: x10 = 800000 = 8e5
int K,
Q,
R,
J,
Z;
int32_t N,
I=80000; /* I=80000: "infinity score" */ ;
int
M=136, /* M=0x88 board system */
S=128, /* dummy square 0x80, highest valid square =127 */
turn=16; // 16=Weiss, 8=Schwarz; turn^=24 wechselt hin unnd her
signed char L,
pval[]={0,2,2,7,-1,8,12,23}, /* relative piece values */
vector[]={-16,-15,-17,0,1,16,0,1,16,15,17,0,14,18,31,33,0, /* step-vector lists */
7,-1,11,6,8,3,6}, /* 1st dir. in vector[] per piece*/
bsetup[]={6,3,5,7,4,5,3,6}, /* initial piece setup */
board[129], /* board: half of 16x8+dummy*/
T[1035]; /* hash translation table */
signed char psymbol[]= ".?+nkbrq?*?NKBRQ";
int mfrom, mto; // current ply from - to
int EPSQ, // e.p. square
RemP; // remove piece
/* recursive minimax search, turn=moving side, n=depth*/
int Minimax(int32_t q, int32_t l, int32_t score, int EPC, int prev, int32_t hashkey)
/* (q,l)=window, score, EnPass_sqr.*/
/* prev=prev.dest; J,Z=hashkeys; return score*/
{
int j,
r,
m,
v,
d,
h,
i,
F,
G,
V,
P,
f=J,
g=Z,
C,
s;
signed char t,
p,
upiece,
x,
y,
X,
Y,
H,
B;
struct HTab *a = HTarray + (J + turn * EPC & HTsize-1); /* lookup pos. in hash table*/
char sbuf[50];
q--; /* adj. window: delay bonus */
turn^=24; /* change sides */
d=a->D;
m=a->V;
X=a->X;
Y=a->Y; /* resume at stored depth */
if(a->K-Z|prev| /* miss: other pos. or empty*/
!(m<=q | X&8&&m>=l | X&S)) /* or window incompatible */
{ d=Y=0; } /* start iter. from scratch */
X&=~M; /* start at best-move hint */
while( d++ < hashkey || d<3 /* iterative deepening loop */
|| prev&K == I
&& ( N<60000 & d<98 /* root: deepen upto time */
|| (K=X, L=Y&~M, d=3)
)
) /* time's up: go do best */
{
x=B=X; /* start scan at prev. best */
h=Y&S; /* request try noncastl. 1st*/
P=d<3 ? I : Minimax(-l,1-l,-score,S,0,d-3); /* Search null move */
m = (-P<l | R>35) ? ( d>2 ? -I : score ) : -P; /* Prune or stand-pat */
N++; /* node count (for timing) */
do
{
upiece=board[x]; /* scan board looking for */
if(upiece & turn) /* own piece (inefficient!)*/
{
r = p = upiece&7; /* p = piece type (set r>0) */
j = vector[p+16]; /* first step vector f.piece*/
while(r = p>2 & r<0 ? -r : -vector[++j] ) /* loop over directions vector[] */
{
labelA: /* resume normal after best */
y=x; /* (x,y)=move */
F=G=S; /* (F,G)=castl.R */
do
{ /* y traverses ray, or: */
H=y=h?Y^h:y+r; /* sneak in prev. best move */
if(y&M)break; /* board edge hit */
m= EPC-S&board[EPC]&&y-EPC<2&EPC-y<2?I:m; /* bad castling */
if(p<3&y==EPC)H^=16; /* shift capt.sqr. H if e.p.*/
t=board[H];
if(t&turn|p<3&!(y-x&7)-!t)break; /* capt. own, bad pawn mode */
i=37*pval[t&7]+(t&192); /* value of capt. piece t */
m=i<0?I:m; /* K capture */
if(m>=l&d>1) goto labelC; /* abort on fail high */
v=d-1?score:i-p; /* MVV/LVA scoring */
if(d-!t>1) /* remaining depth */
{
v=p<6?board[x+8]-board[y+8]:0; /* center positional pts. */
board[G]=board[H]=board[x]=0;board[y]=upiece|32; /* do move, set non-virgin */
if(!(G&M))board[F]=turn+6,v+=50; /* castling: put R & score */
v-=p-4|R>29?0:20; /* penalize mid-game K move */
if(p<3) /* pawns: */
{
v-=9*((x-2&M||board[x-2]-upiece)+ /* structure, undefended */
(x+2&M||board[x+2]-upiece)-1 /* squares plus bias */
+(board[x^16]==turn+36)) /* kling to non-virgin King */
-(R>>2); /* end-game Pawn-push bonus */
V=y+r+1&S?647-p:2*(upiece&y+16&32); /* promotion or 6/7th bonus */
board[y]+=V;
i+=V; /* change piece, add score */
}
v+= score+i;
V=m>q ? m : q; /* new eval and alpha */
J+=K(y+0,board[y])-K(x+0,upiece)-K(H+0,t);
Z+=K(y+8,board[y])-K(x+8,upiece)-K(H+8,t)+G -S; /* update hash key */
C=d-1-(d>5&p>2&!t&!h);
C=R>29|d<3|P-I?C:d; /* extend 1 ply if in check */
do {
s=C>2|v>V?-Minimax(-l,-V,-v, /* recursive eval. of reply */
F,0,C):v; /* or fail low if futile */
} while( s>q & ++C<d );
v=s;
if(prev&&K-I&&v+I&&x==K&y==L) /* move pending & in root: */
{
Q=-score-i; EPSQ=F; /* exit if legal & found */
a->D=99;a->V=0; /* lock game in hash as draw*/
R+=i>>7;
return l; /* captured non-P material */
}
J=f;
Z=g; /* restore hash key */
board[G]=turn+6;
board[F]=board[y]=0;
board[x]=upiece;
board[H]=t; /* undo move,G can be dummy */
}
if(v>m) /* new best, update max,best*/
{
m=v,X=x,Y=y|S&F; /* mark double move with S */
}
if(h)
{
h=0;
goto labelA; /* redo after doing old best*/
}
if (
x+r-y|upiece&32| /* not 1st step,moved before*/
p>2 & (
p-4|j-7|| /* no P & no lateral K move,*/
board[G=x+3^r>>1&7]-turn-6 /* no virgin R in corner G, */
|| board[G^1] | board[G^2] ) /* no 2 empty sq. next to R */
)
{
t+=p<5;
} /* fake capt. for nonsliding*/
else F=y; /* enable e.p. */
} while(!t); /* if not capt. continue ray*/
}
} // (upiece & turn)
} while((x=x+9&~M)-B); /* next sqr. of board, wrap */
labelC:
if (m>I-M|m<M-I) d=98; /* mate holds to any depth */
m= m+I|P==I ? m : 0; /* best loses K: (stale)mate*/
if(a->D<99) { /* protect game history */
a->K=Z;
a->V=m;
a->D=d; /* always store in hash tab */
a->X=X|8*(m>q)|S*(m<l);
a->Y=Y; /* move, type (bound/exact),*/
}
/* uncomment for Kibitz */
//if(prev) sprintf(sbuf, "%2d ply, %9d searched, score=%6d by %c%c%c%c\n",
// d-1, N-S, m, 'a'+(X&7),'8'-(X>>4),'a'+(Y&7),'8'-(Y>>4&7));
if(prev && X!=Y) {
sprintf(sbuf, "\n%2d ply, searched: %9d ", d-1, N-S );
Serial.print(sbuf);
}
else
if( ((N-S)%10000)<1) Serial.print(".");
} // while (iterative deepening loop)
turn^=24; /* change sides back */
mfrom=K; mto=L;
return m+= m<score; /* delayed-loss bonus */
}
void chess()
{
int32_t score, i;
int16_t oldto, oldEPSQ;
char sbuf[50], sbuf2[50];
char cstring[20];
signed char oboard[129], spiece;
K=8;
while(K--)
{
board[K]=(board[K+112]=bsetup[K]+8)+8;
board[K+16]=18;
board[K+96]=9; /* initial board setup*/
L=8;
while(L--)board[16*L+K+8]=(K-4)*(K-4)+(L-3.5)*(L-3.5); /* center-pts table */
} /*(in unused half board[])*/
N=1035;
while(N-->M)T[N]=rand()>>9;
/* play loop */
while(1)
{
N=-1;
Serial.print("\n");
sprintf(sbuf," A B C D E F G H \n --------------- \n"); Serial.print(sbuf);
while(++N<121) { /* print board */
if(N&8 && (N+7!=0) ) {sprintf(sbuf,"%3d \n", 1+((120-N)>>4)); Serial.print(sbuf); N+=7; }
else {
if(N%8==0) {sprintf(sbuf, "%3d ", 1+((120-N)>>4)); Serial.print(sbuf); }
sprintf(sbuf," %c", psymbol[board[N]&15]); Serial.print(sbuf);
}
}
sprintf(sbuf," --------------- \n A B C D E F G H "); Serial.print(sbuf);
if(turn==16) sprintf(sbuf,"\n> WHITE: "); else sprintf(sbuf,"\n> BLACK: ");
Serial.print(sbuf);
i = 0;
strcpy(cstring,"");
do {
while (Serial.available()==0);
cstring[i] = Serial.read();
if(cstring[i]==13) {
cstring[i]=0;
break;
}
else i++;
} while(i < 10);
K=I;
if(cstring[0]!=0) { /* parse entered move */
K= cstring[0]-16*cstring[1]+799;
L= cstring[2]-16*cstring[3]+799;
}
/*
Serial.print("\n DEBUG cstring : "); Serial.print(cstring);
sprintf(sbuf,"\n DEBUG K: %d \n DEBUG L: %d \n", K, L);
Serial.print(sbuf);
*/
memcpy(oboard, board, sizeof(board));
oldto=mto;
oldEPSQ=EPSQ;
score=Minimax(-I, I, Q, EPSQ, 1, 3); /* think or check & do*/
if(score!=15) {
RemP=S;
if(oboard[mto]) RemP=mto;
if(mto==oldEPSQ) RemP=oldto;
spiece=psymbol[board[mto]&15];
if(spiece=='*' || spiece=='+') spiece=' ';
sprintf(sbuf,"\n\nmoved: >> %c %c%c", spiece,'a'+(mfrom&7),'8'-(mfrom>>4) );
if(oboard[mto]) strcat(sbuf," X ");
else strcat(sbuf,"-");
sprintf(sbuf2,"%c%c ", 'a'+(mto&7),'8'-(mto>>4&7));
strcat(sbuf, sbuf2);
Serial.print(sbuf);
sprintf(sbuf, " \nDEBUG: %d to %d \n", mfrom, mto);
Serial.print(sbuf);
sprintf(sbuf," EPsq: %c%c (%3d)\n",
'a'+(EPSQ&7), '8'-(EPSQ>>4&7), EPSQ); Serial.print(sbuf);
sprintf(sbuf," RemP: %c%c (%3d)\n\n",
'a'+(RemP&7), '8'-(RemP>>4&7), RemP); Serial.print(sbuf);
}
else printf("\n\nILLEGAL!\n");
}
}
void setup() {
Serial.begin(9600);
}
void loop() {
chess();
while(1);
}
...works !
