git mv *.hint -> README.md
There is one exception:
$ find . -name '*.hint' -execdir git mv '{}' README.md \;
git statufatal: destination exists, source=1992/albert/albert.hint, destination=1992/albert/README.md
Looking at the two files they differ quite a bit so I've not changed it.
I'll bring this up on GitHub.
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Best AI:
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Doug Beardsley
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Southern Adventist University
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359 Davis Rd. NW
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Cleveland, TN 37312
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USA
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Judge's Remarks:
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To build:
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make dgbeards
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Try:
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./dgbeards
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This is probably the worst AI we've ever seen. So, then, why did
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the entry win? Because it's *trying* to lose.
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This is also one of the first chess games we've seen.
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Of particular interest is the author's decision that the program should
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crash if it loses. I've played chess with a lot of people like that, and
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I appreciate the realism.
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Selected Author's Comments:
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FAQ:
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Q: What does this program do?
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A: It lets the user play two player or single player games of suicide
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chess. Suicide Chess (also known as Losing Chess) is a variant of normal
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chess. It is played on the same board and uses the same pieces. Here is
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a list of the differences:
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1. The object of the game is to get to a position where you have no legal
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moves. This is usually accomplished by losing all of your pieces.
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Sometimes, the game can end when you still have some pawns on the board,
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but they are blocked and cannot move. The general rule is if a player
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has no legal moves, the game is over. The winner is the player with fewer
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pieces on the board. This is almost always the same player that had no
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moves, but not always.
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2. In suicide chess, piece captures are compulsory. If a player can
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capture an opponent's piece, he is required to do so. If he can capture
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more than one of the opponent's pieces or can capture one piece with more
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than one of his own pieces, he can choose which capture to play.
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3. The king is not significant. There is no concept of check and the king
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can be captured.
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4. Because of rule 3, pawns are allowed to promote to a king.
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5. Castling is not allowed.
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Q: How do you use this program?
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A: The program is fairly straightforward. When you start the program,
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it displays the opening position for a game of suicide chess and waits
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for user input. Commands are as follows:
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quit - Quits the program
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g - Causes the computer to make a move
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Moves are represented by the long algebraic notation for the move. For
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those not familiar with long algebraic notation, a move consists of a
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square to move from followed by a square to move to. Squares are denoted
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by a letter and a number. The letter specifies the column or file of the
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square and the number specifies the row rank. Files are named from left
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to right by the letters a-h. Rows are numbered from bottom to top with
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the numbers 1-8. A sample move from the opening position is e2e3. This
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means to move a piece from square e2 to e3. From the opening position,
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this corresponds to moving the king pawn forward one square. This is
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generally to be considered one of the best opening moves in suicide
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chess. All moves, captures and otherwise, are represented with this
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notation. A special case is pawn promotion moves. They use the same
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notation followed by an '=' and a letter representing the piece to
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promote to. The letters are R,N,B,Q,K representing rook, knight, bishop,
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queen, and king respectively. The letters must be upper case.
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You can also specify a command line argument of a single digit to change
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the search depth of the program. If no argument is specified, it
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defaults to a depth of 3.
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Q: Are there any limitations in your program?
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A: Yes. The first of the limitations is that you can only play legal
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moves according to the rules of suicide chess. En passant captures are
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not recognized. They are rarely encountered in suicide chess and when
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they do happen, they usually do not change the outcome of the game. As
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mentioned above, castling is not allowed either.
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It also does not detect the end of the game. It can see sure wins or
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losses several moves ahead, but does not announce the end of a game or
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the winner. Given the existing code it is easy to do this, but it was
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deemed unnecessary fluff.
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Q: What is the playing strength of this program?
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A: Playing strength is a relative term. Relative to other computer
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programs that play suicide chess, it is about the bottom. There is one
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freeware program in existence called kenny that this program can beat,
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but that is about it.
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Suicide chess is a very tactical game. Most humans who do not have any
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experience in suicide chess will lose to this program. The Free Internet
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Chess Server (http://www.freechess.org) is a free online chess server
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that supports suicide chess. This server keeps track of ratings. The
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human ratings for suicide chess range from 1000 to about 2400. This
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program would probably be rated somewhere around 1700-1900. It is better
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than most players, but will get destroyed by experienced human opponents.
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This program searches to a fixed depth of 3 ply. Because it does not
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search very deep, it performs very poorly in quiet strategic positions.
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In such positions, it will often just shuffle pieces around aimlessly
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until a tactical exchange presents itself.
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A small amount of randomness has been added to make the program a more
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interesting opponent. The to avoid a call to srand(), rand() and the
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extra code for the required include files, the time() function is used as
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the source of random data. It is a slow function, and since it is
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executed inside the search loop, there is a significant performance
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decrease. To make it faster, replace the time() call with rand() and add
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the line srand(time(0)); to the beginning of main(). I used the more
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inefficient time() function to illustrate a different (and somewhat
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obfuscated?) way of generating random numbers.
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Q: Why is this program obfuscated?
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A: Here are several reasons:
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First, without preprocessing, the code is not easy to read. The
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preprocessor is used to compress the code and obfuscate it. The main
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obstacle to entering this program is the source code size limit. This is
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the reason that the preprocessor was used so liberally. It is one of the
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best ways to compress C source code.
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Second, when possible, variables in the program were made global. Their
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names are not descriptive and they are used for a variety of purposes
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throughout the program. Because of this, it is difficult to determine
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exactly what the code does even after preprocessing and beautifying the
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code.
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Third, all function names are a single character and are obviously not
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descriptive of they're actual purpose. Again this serves the dual
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purpose of compression and obfuscation.
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Fourth, most string variables have been encoded. This encoding serves
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to obfuscate the program as well as reduce the number of countable
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characters and get the program under the size limit of this year's IOCCC.
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There are some places where other simple encoding methods are used to
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hide the real purpose of strings. These layers of obscurity cannot be
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penetrated by just preprocessing and beautifying the program.
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Fifth, various small obfuscations have been used in places all over the
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program. Short circuit evaluation is used as a substitute for if()
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statements in some places. The ternary operator is used. In the
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author's opinion, use of the ternary operator is almost always a strong
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argument for employee turnover.
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Last, if you have succeeded in wading through the previous layers of
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obfuscation, you are confronted by the fact that the game that it
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implements is an obscure game. Casual inspection of the program might
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lead one to believe that it is an implementation of classic chess, but
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this is not so.
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Q: What about the compiler warnings?
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A: When compiled with gcc -Wall, the compiler generated the following
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warnings:
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suggest parentheses around + or - in operand of &
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array subscript has type 'char'
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return type defaults to 'int'
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control reaches end of non-void function
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value computed is not used
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The "value computed is not used" warning happens because I use the &&
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operator and take advantage of short circuit evaluation instead of using
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an if() statement.
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The "suggest parentheses..." warnings are given because of expressions
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that depend on operator precedence details in the C language.
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Eliminating these warnings would reduce obfuscation.
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The other warnings are there because it would require more code to
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eliminate them and that can't be done given the size limit.
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Q: Why does this program crash when it loses?
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A: What better way to admit defeat? The author thought this was
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appropriate sportsmanship for a program of this genre and can think of
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no worse job than trying to find an elusive bug in an intentionally
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obfuscated program.
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[judge's note: This was followed by a description of the bug, and
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the comment:]
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(Note, if this program wins, the author thinks it would be good to leave
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this information out of the remarks and encourage others to try and
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figure it out for themselves)
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[should you be too lazy to figure it out yourself, here's the author's
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fix. I would have rot13'd it, but the punctuation would have survived.]
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begin 644 fix.txt
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M5&AI<R!B=6<@8V%N(&)E(&9I>&5D(&EN(&$@;G5M8F5R(&]F('=A>7,L(&)U
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M="!T:&5R90II<R!A('=A>2!T:&%T(&%D9',@;VYL>2!O;F4@8GET92!T;R!T
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M:&4@<V]U<F-E(&-O9&4N("!);B!T:&4@<W1A=&5M96YT"G,]*&4]+58H;BTQ
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M+&\I*3YS/UD]1RQE.G,[(&-H86YG92!T:&4@/B!T;R!A(#X](&%N9"!T:&4@
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38G5G('=I;&P@8F4@9V]N92X*"FYG
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`
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end
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