Grand Prize: <merlyn@digibd.com> Brian Westley    Brian Westley (Merlyn LeRoy on usenet)    DigiBoard, Inc.    1026 Blair Ave.    St. Paul, MN  55104  USAJudges' comments:    Make and run as follows:	make westley	westley [move_location] | tee nextmove.c        where the 'move_location' is a digit from 1 to 9 that represents    a move on a tic-tac-toe board:		1 2 3		4 5 6		7 8 9    If you omit 'move_location', then the computer moves first.  For your     next move, recompile nextmove.c and play it again:	make nextmove	nextmove move_location | tee nextmove.c    We have provided the shell script, ttt, to make it easier to play the game:	make ttt	ttt [first_move]	<- omit first arg to have it move first	ttt next_move    The shell script determines when the game is over, and automatically     replaces merlyn.c with an improved version after a loss.  The ttt script     has two other modes:	ttt quitgame	<- cancel any game in process, revert to merlyn.c	ttt clobber	<- remove all game files, revert to original source     Try not to cheat, the computer has not learned how to catch you doing it.Selected notes from the author:    A tic-tac-toe self-modifying program that "learns".  This C program    plays standard tic-tac-toe on itself.  The code is written as a    tic-tac-toe grid; moves are carried out within the code.    The human is X, the computer 0 [sic, "zero", not letter "O"].    The program, when run, reproduces itself with both the player's    move and the computer's move added.  Recompile THIS program (using    the same compile line) and repeat until the game is finished.    If the computer wins, the "straight face" in the upper right-hand    corner ":-|" will change into a happy face ":-)".  If it is a draw,    the face does not change.  If the computer loses, the board is    blanked and the face changes into a sad face ":-(".  If this    happens, the blank board should replace the original program; the    computer changes its play and will continue to do so until it no    longer loses games.    If you want a program that never loses, simply replace the string    "9999999999  :-| " with "9883857753  :-| ".    How It Works (rot13 to read)    ----------------------------    Gur iregvpny "onef" bs gur tevq ner vqragvpny shapgvbaf, jvgu gur    anzr bs gur shapgvba nf n(), o(), be p().  Nsgre rnpu shapgvba vf    pnyyrq, gur tybony inevnoyrf K naq B pbagnva ovgznfxf bs jurer nyy    gur Kf naq Bf ner cynprq.  Gur fgngrzrag:	K=-   <pune>   -1;    rinyhngrf gb 1, -1, be -2 jura K vf 1 naq <pune> vf bar bs "K",    "0", be " ".  Gur shapgvba F(&K) frgf gur nccebcevngr ovgf va    (tybony ine) K naq B naq erfrgf gur inyhr bs &K gb 1.  Guvf vf ubj    gur pheerag cbfvgvba vf pbzchgrq.    Gur cynlre'f zbir vf BE'q vagb gur K znfx, naq (vs vg vf gur    bcravat zbir) gur fgengrtl fgevat'f svefg punenpgre vf frg gb gur    cynlre'f svefg zbir (be "5" vs gur pbzchgre zbirf svefg).    Gur rinyhgvba shapgvba l(Z) purpxf vs gur znfx unf n jvaavat    cnggrea (nal bs gur svefg rvtug ovgznfxf bs gur j[] neenl), naq    frgf gur inevnoyr d gb 0 vs vg qbrf.    Gur cynlre'f zbir vf rinyhngrq gb frr vs gur uhzna unf jba.  Gur    fzvyrl vf frg gb :-) be :-( qrcraqvat ba guvf.  Nyfb, vs gur uhzna    unf jba, gur qvtvg va gur fgengrtl fgevat vf qrperzragrq gb punatr    gur pbzchgre'f cynl sbe arkg tnzr.    Vs gur uhzna unf ABG jba, gur r(A,Z) shapgvba rinyhngrf vs NAL zbir    abg va znfx A pna cebqhpr n jva va znfx Z.  Gur svefg rinyhngvba    r(K,B) purpxf vs B pna znxr n yrtny jvaavat zbir.  Vs fb, gur    pbzchgre unf n jvaavat zbir naq znxrf vg.  Vs abg, gur fzvyrl vf    frg gb :-|, naq n aba-jvaavat zbir vf trarengrq.    N aba-jvaavat zbir svefg purpxf vs K pna jva va bar zbir; vs fb,    guvf zbir vf fryrpgrq, oybpxvat gur jva.  Bgurejvfr, n zbir vf    trarengrq ol ybbxvat qbja gur yvfg bs "zbir grzcyngrf".  Gur svefg    zbir grzcyngr gung trarengrf n zbir gung vf ABG nyernql bpphcvrq ol    na K be B vf erghearq.    Gur "zbir grzcyngrf" ner fgngvp gvp-gnp-gbr cbfvgvbaf gung trarengr    cbffvoyr zbirf ol znxvat gur r() shapgvba erghea "jvaavat" zbirf,    r.t. gur grzcyngr:	. . .	B , B    (guvf vf gur inyhr 40; 2^3+2^5)	. . .    ("B"f ner 1 ovgf, "." naq "," ner 0 ovgf)    ...jvyy znxr gur r() shapgvba erghea n pragre zbir, nf    guvf vf gur bayl zbir gung cebqhprf guerr va n ebj.  Abgvpr gung    gur pbzchgre qbrf abg pbafvqre juvpu pryyf pbagnva Kf naq Bf jura    znxvat n grzcyngr zbir, bayl juvpu pryyf ner rzcgl naq abg-rzcgl.    Guvf znxrf sbe hahfhny cynl.    Gur grzcyngrf ner pnershyyl pubfra gb riraghnyyl oybpx nyy gencf    gung K pna gel, ol whfg oyhaqrevat va gur jnl.    Nyfb abgr gung gur jvaavat & fgengrtl grzcyngrf ner cneg bs gur    pbzcvyr yvar, znxvat vg cbffvoyr gb punatr gur ehyrf bs gur tnzr ol    punatvat gur pbzcvyr yvar.    Gur grzcyngrf ner:	B , B	, , ,	B , B	, . .	. B .	. . B	. . .	B , B	. . .	. . .	B B ,	. . .	. . .	B , B	. . .	. , ,	. B .	B B ,	B , B	, , .	B . .	, . B	B , B	B . ,	B . ,	B , B	, . B	B , B	, , ,	B , B    N qvtvg bs "9" zrnaf fgneg jvgu gur svefg grzcyngr, "8" fgnegf ng    gur frpbaq, rgp.  Gur grzcyngrf ner fpnaarq hagvy n yrtny zbir vf    sbhaq.  N grzcyngr vf fpnaarq sebz obggbz gb gbc, evtug gb yrsg    (v.r.  zbir 9 vf grfgrq svefg, gura 8, qbja gb zbir 1).