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; This file is part of "NOVA":  NOVA = search + COCOMO tools
; Copyright, 2008, Tim Menzies tim@menzies.us
;
; NOVA is free software: you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation, either version 3 of the License, or
; (at your option) any later version.
;
; NOVA is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.
; You should have received a copy of the GNU General Public License
; a long with NOVA.  If not, see <http://www.gnu.org/licenses/>.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defsearch seesaw2 ()

  ;; start by moving all non-singleton treatments to the closed list
  ;; this simplifies the creation of singleton treatments
  (move-elts (non-singletons? open) open closed)
  (save-state)
  (if *debug-search* (print-state (first-state? path)))
  (loop

   ;; if the solution is fully constrained, return
   (if (= (constrained% (first-state? path)) 1) (return))

   ;; generate min and max singleton treatments for each unconstrained feature
   (dolist (treatment (coalesce-treatments closed))
     (let ((feature (car treatment))
	   (range   (cdr treatment)))
       (unless (find feature open :key #'car)
	 (with-new-path
	   (move-elt (list feature (apply #'min range)) closed open)
	   (save-state)
	   (push path paths))
	 (with-new-path
	   (move-elt (list feature (apply #'max range)) closed open)
	   (save-state)
	   (push path paths)))))

   ;; choose the best treatment
   (let* ((*monte-carlo-iterations* 100)  ; adjust this to affect speed/min energy accuracy
	  (best-e                   (energy? (min-energy? paths))))
     (dolist (new-path paths)
       (when (= best-e (energy? (min-energy? new-path)))
	 (let ((best (set-difference (state-open (first-state? new-path))
				     open
				     :test #'equal)))
	   (move-elt (car best) closed open)
	   (return)))))
   (save-state)
   (energy? (first-state? path))
   (if *debug-search* (print-state (first-state? path)))
   (setf paths nil))
  (if *debug-search* (terpri)))