;;;;***************************************************************************
;;;;
;;;; FILE IDENTIFICATION
-;;;;
+;;;;
;;;; Name: edge-table.lisp
;;;; Purpose: Edge table routines for reversi
;;;; Programer: Kevin M. Rosenberg based on code by Peter Norvig
;;;; Date Started: 1 Nov 2001
;;;;
-;;;; $Id: edge-table.lisp,v 1.6 2003/06/17 05:47:18 kevin Exp $
+;;;; $Id$
;;;;
-;;;; This file is Copyright (c) 2001-2003 by Kevin M. Rosenberg
+;;;; This file is Copyright (c) 2001-2003 by Kevin M. Rosenberg
;;;; and Copyright (c) 1998-2002 Peter Norvig
;;;;
;;;; Reversi users are granted the rights to distribute and use this software
(defun make-edge-table ()
(setq *edge-table* (make-array (expt 3 10) :element-type 'fixnum
- :adjustable nil :fill-pointer nil))
+ :adjustable nil :fill-pointer nil))
(init-edge-table)
*edge-table*)
"Call fn on all edges with n pieces."
;; Index counts 1 for player; 2 for opponent
(declare (fixnum n index)
- (type player player)
- (type square index)
- (type (simple-array fixnum (100)) board)
- (list squares)
- (optimize (speed 3) (space 0) (safety 0)))
+ (type player player)
+ (type square index)
+ (type (simple-array fixnum (100)) board)
+ (list squares)
+ (optimize (speed 3) (space 0) (safety 0)))
(cond
((< (length squares) n) nil)
((null squares) (funcall fn board index))
(t (let ((index3 (* 3 index))
(sq (first squares)))
- (declare (fixnum index3 sq))
+ (declare (fixnum index3 sq))
(map-edge-n-pieces fn player board n (rest squares) index3)
(when (and (plusp n) (= (bref board sq) empty))
(setf (bref board sq) player)
(defun possible-edge-moves-value (player board index)
- "Consider all possible edge moves.
+ "Consider all possible edge moves.
Combine their values into a single number."
(declare (type board board)
- (type player player)
- (type square index))
+ (type player player)
+ (type square index))
(combine-edge-moves
(cons
(list 1.0 (aref *edge-table* index)) ;; no move
"The index counts 1 for player; 2 for opponent,
on each square---summed as a base 3 number."
(declare (type board board)
- (type player player)
- (type cons squares)
- (optimize (speed 3) (safety 0) (space 0)))
+ (type player player)
+ (type cons squares)
+ (optimize (speed 3) (safety 0) (space 0)))
(let ((index 0))
(declare (fixnum index))
(dolist (sq squares)
(declare (type square sq))
- (setq index
- (the fixnum
- (+
- (the fixnum (* index 3))
- (the fixnum (cond ((= (bref board sq) empty) 0)
- ((= (bref board sq) player) 1)
- (t 2)))))))
+ (setq index
+ (the fixnum
+ (+
+ (the fixnum (* index 3))
+ (the fixnum (cond ((= (bref board sq) empty) 0)
+ ((= (bref board sq) player) 1)
+ (t 2)))))))
index))
(defun possible-edge-move (player board sq)
"Return a (prob val) pair for a possible edge move."
(declare (type board board)
- (type player player)
- (type square sq))
+ (type player player)
+ (type square sq))
(let ((new-board (replace-board (svref *ply-boards* player) board)))
(make-move sq player new-board)
(list (edge-move-probability player board sq)
(- (aref *edge-table*
- (edge-index (opponent player)
+ (edge-index (opponent player)
new-board *top-edge*))))))
(defun combine-edge-moves (possibilities player)
"Combine the best moves."
(declare (type player player)
- (optimize (speed 3) (safety 0) (space 0)))
+ (list possibilities)
+ (optimize (speed 3) (safety 0) (space 0)))
(let ((prob 1.0)
(val 0.0)
(fn (if (= player black) #'> #'<)))
(declare (short-float prob val))
(loop for pair in (sort possibilities fn :key #'second)
while (>= prob 0.0)
- do (incf val (* prob (first pair) (second pair)))
- (decf prob (* prob (first pair))))
+ do (incf val (* prob (first pair) (second pair)))
+ (decf prob (* prob (first pair))))
(round val)))
(defun edge-move-probability (player board square)
"What's the probability that player can move to this square?"
(declare (type board board)
- (type player player)
- (type square square)
- (optimize (speed 3) (safety 0) (space 0)))
+ (type player player)
+ (type square square)
+ (optimize (speed 3) (safety 0) (space 0)))
(cond
((x-square-p square) .5) ;; X-squares
((legal-p square player board) 1.0) ;; immediate capture
(defun count-edge-neighbors (player board square)
"Count the neighbors of this square occupied by player."
(declare (type board board)
- (type player player)
- (type square square))
+ (type player player)
+ (type square square))
(count-if #'(lambda (inc)
- (declare (type square inc))
+ (declare (type square inc))
(= (bref board (+ square inc)) player))
'(+1 -1)))
(defparameter *static-edge-table*
- '#2A(;stab semi un
+ '#2A(;stab semi un
( * 0 -2000) ; X
( 700 * *) ; corner
(1200 200 -25) ; C
(defun static-edge-stability (player board)
"Compute this edge's static stability"
(declare (type board board)
- (type player player)
- (optimize (speed 3) (safety 0) (space 0)))
+ (type player player)
+ (optimize (speed 3) (safety 0) (space 0)))
(loop for sq in *top-edge*
for i from 0
- sum (the fixnum
- (cond
- ((= (bref board sq) empty) 0d0)
- ((= (bref board sq) player)
- (aref *static-edge-table* i
- (piece-stability board sq)))
- (t (- (aref *static-edge-table* i
- (piece-stability board sq))))))))
+ sum (the fixnum
+ (cond
+ ((= (bref board sq) empty) 0)
+ ((= (bref board sq) player)
+ (aref *static-edge-table* i
+ (piece-stability board sq)))
+ (t (- (aref *static-edge-table* i
+ (piece-stability board sq))))))))
(eval-when (:compile-toplevel :load-toplevel :execute)
(let ((stable 0) (semi-stable 1) (unstable 2))
(declare (type fixnum stable semi-stable unstable))
-
+
(defun piece-stability (board sq)
(declare (type board board)
- (fixnum sq)
- (optimize (speed 3) (safety 0) (space 0)))
+ (fixnum sq)
+ (optimize (speed 3) (safety 0) (space 0)))
(cond
- ((corner-p sq) stable)
- ((x-square-p sq)
- (if (eql (bref board (corner-for sq)) empty)
- unstable semi-stable))
- (t (let* ((player (bref board sq))
- (opp (opponent player))
- (p1 (find player board :test-not #'eql
- :start sq :end 19))
- (p2 (find player board :test-not #'eql
- :start 11 :end sq
- :from-end t)))
- (declare (fixnum player opp))
- (cond
- ;; unstable pieces can be captured immediately
- ;; by playing in the empty square
- ((or (and (eql p1 empty) (eql p2 opp))
- (and (eql p2 empty) (eql p1 opp)))
- unstable)
- ;; Semi-stable pieces might be captured
- ((and (eql p1 opp) (eql p2 opp)
- (find empty board :start 11 :end 19))
- semi-stable)
- ((and (eql p1 empty) (eql p2 empty))
- semi-stable)
- ;; Stable pieces can never be captured
- (t stable))))))))
+ ((corner-p sq) stable)
+ ((x-square-p sq)
+ (if (eql (bref board (corner-for sq)) empty)
+ unstable semi-stable))
+ (t (let* ((player (bref board sq))
+ (opp (opponent player))
+ (p1 (find player board :test-not #'eql
+ :start sq :end 19))
+ (p2 (find player board :test-not #'eql
+ :start 11 :end sq
+ :from-end t)))
+ (declare (fixnum player opp))
+ (cond
+ ;; unstable pieces can be captured immediately
+ ;; by playing in the empty square
+ ((or (and (eql p1 empty) (eql p2 opp))
+ (and (eql p2 empty) (eql p1 opp)))
+ unstable)
+ ;; Semi-stable pieces might be captured
+ ((and (eql p1 opp) (eql p2 opp)
+ (find empty board :start 11 :end 19))
+ semi-stable)
+ ((and (eql p1 empty) (eql p2 empty))
+ semi-stable)
+ ;; Stable pieces can never be captured
+ (t stable))))))))
(defun init-edge-table ()
"Initialize *edge-table*, starting from the empty board."
;; Initialize the static values
(declare (optimize (speed 3) (safety 0) (space 0)))
- (loop for n-pieces from 0 to 10 do
+ (loop for n-pieces from 0 to 10 do
(map-edge-n-pieces
- #'(lambda (board index)
- (declare (type board board)
- (fixnum index))
+ #'(lambda (board index)
+ (declare (type board board)
+ (fixnum index))
(setf (aref *edge-table* index)
(the fixnum (static-edge-stability black board))))
- black (initial-board) n-pieces *top-edge* 0))
+ black (initial-board) n-pieces *top-edge* 0))
;; Now iterate five times trying to improve:
- (dotimes (i 5)
+ (dotimes (i 5)
(declare (fixnum i))
;; Do the indexes with most pieces first
- (loop for n-pieces fixnum from 9 downto 1 do
+ (loop for n-pieces fixnum from 9 downto 1 do
(map-edge-n-pieces
#'(lambda (board index)
- (declare (type board board)
- (fixnum index))
+ (declare (type board board)
+ (fixnum index))
(setf (aref *edge-table* index)
(the fixnum (possible-edge-moves-value black board index))))
black (initial-board) n-pieces *top-edge* 0))))