我有两个罐子的问题。 初始状态为[0,0],每个罐子的容量为[4,9],目标状态为[0,6] 合法动作:将1号或2号罐装满,空1号或2号罐,将其中一个罐放入另一个罐中。在
import search #get the interface
import sys
sys.setrecursionlimit(5000)
class two_jugs(search.Nodes):
#return the starting state vessel 1: 0, vessel 2: 0
def start(self):
return [0,0]
#returns true if node is equal to goal node
def goal(self,node):
return node ==(0,6)
#yields the successors of the configuration indicated by node
def succ(self,node):
# set capacities for vessel 1: 4, vessel 2 : 9
c = [4,9];
#stop at second last
for i in range(len(node)-1):
#create a safety copy
new_node = node[:]
#fill vessel 1
if new_node[i]<=0:
new_node[i]=c[i]
print new_node
#fill vessel 2
if new_node[i+1]<=0:
new_node[i+1]=c[i+1]
print new_node
#dump vessel i+1
if (new_node[i+1]>0):
new_node[i+1]=0
print new_node
#poor vessel i to vessel i+1
if (new_node[i+1]<c[i+1] and new_node[i]>0):
#calculate the difference
d = min(new_node[i],c[i+1]-new_node[i+1])
new_node[i]= new_node[i]-d
new_node[i+1]= new_node[i+1]+d
print new_node
#dump vessel i
if (new_node[i]>0):
new_node[i]=0
print new_node
#poor vessel i+1 to vessel 1
if (new_node[i]<c[i] and new_node[i+1]>0):
#calculate the difference
d = min(new_node[i+1],c[i]-new_node[i])
#set new node
new_node[i+1]= new_node[i+1]-d
new_node[i]= new_node[i]+d
yield new_node
print new_node
问题是既然我已经声明了所有的合法移动,为什么我的程序只返回一个合法移动的结果?例如,从开始状态[0,0]开始,当我运行程序时,它返回[4,0]、[0,4]、[0,9]和其他可能的结果,直到递归停止,但不是我的目标状态。 我错过了什么?在
广度优先搜索类:
^{pr2}$搜索类:
class Nodes:
def succ(self,n):
raise Exception, "Successor undefined"
def start (self):
raise Exception, "Start undefined"
def goal (self,n):
raise Exception, "Goal undefined"
运行程序的类:
import decant
from breadth_first_search import *
dec = decant.Decant()
print breadth_first_search(dec,[[dec.start()]])
您的第一个错误是给类
2jugs
添加标签。python中的变量名(包括类和函数的名称)以及许多其他编程语言都不能以数字开头。因此,将2jugs
重命名为two_jugs
。在precise rule for identifiers in python是标识符,必须以大写(
A-Z
)、小写(a-z
)或下划线(_
)开头。标识符的以下字符也可以包含数字(0-9
)。(规则在Backus-Naur form中指定)。在相关问题 更多 >
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