从一个5加仑的空水壶和一个11加仑的空水壶开始，我们怎么能在11加仑的水壶里只有3加仑水，而5加仑的水壶是空的呢？
我想用Lisp编写一个函数，计算这个拼图中任何状态的继承状态列表
我的解决方案
(0 0) > (5 0) > (0 5) > (5 5) > (0 10 ) > (5 10)>(4 11)>(4 0)>(0 4)>(5 4)>(0 9)>(5 9)>(3 11)>(3 0)>(0 3)
如何实现
successors功能？ (setq initial-state '(0 0))
(setq fill-jug1-state '(5 0))
(setq fill-jug2-state '(0 11))
(setq full '(5 11))
(defparameter *jug-1* 5)
(defparameter *jug-2* 11)
(defun successors (initial-state)
)
请帮忙！!!!
最佳答案
下面是一个开始的提示：
(defun successors (state) ; for each state
(let ((jug1 (first state)) ; gallons in jug1 for state
(jug2 (second state)) ; gallons in jug2 for state
(new-states nil)) ; successor states of state
(when (< jug1 5) ; if jug1 is not full
(push (list 5 jug2) new-states)) ; then fill jug1
; do the same for jug2
; ...
(when (> jug1 0) ; if jug1 has some water
;... empty jug1, that is, new-state = (0 jug2)
; do the same for jug2 if jug2 has some water
;...
(when (and (> jug2 0) (< jug1 5)) ; if jug2 can give water to jug1
; then pour the water of jug2 in jug1
(push (list (min 5 (+ jug1 jug2))
(max (- jug2 (- 5 jug1)) 0)) new-states))
; do the same for the opposite situation
;...
new-states)) ; finally return the set of new states