perm filename MIDTER.F73[206,LSP] blob sn#072126
filedate 1973-11-15 generic text, type C, neo UTF8
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\CCOMPUTER SCIENCE DEPARTMENT
\CCS 206 COMPUTING WITH SYMBOLIC EXPRESSIONS FALL 1973
\F0\COpen Books and Notes
\J Write LISP functions as follows using the M-expression
notation used in class:
1. \F1commontail[u,v]\F0 is the longest common sublist of
\F1u\F0 and \F1v\F0 ending with the ends of the lists. Thus
\F1commontail[\F0(A B C D E),(A C D E)] = (C D E).
2. \F1permut u\F0 is a list of all the permutations of the
list \F1u\F0. Thus
\F1permut \F0(A B C) = ((A B C)(A C B)(B A C)(B C A)(C A B)(C B A)).
The order in which the permutations are listed is not important here.
3. Devise a list structure representation of positions in the
game of tic-tac-toe (noughts and crosses), and write functions \F1ter p\F0,
which tells whether the game is over in position \F1p\F0,
\F1imval p\F0 which tells the value of the game for a terminated
position (use -1, 0 and 1 for values), and \F1successors p\F0 which
gives the successors to a non-terminating position \F1p\F0. Make no
special effort to achieve efficiency.\.