#!/usr/bin/env python
# encoding=utf-8 (pep 0263)
from linked_lists import LinkedList, Cons, Nil, member, append
def is_goal(x):
# zavisi na resenem problemu
return x == "E"
def solution(node):
for path in breadth_first_search(LinkedList([LinkedList(node)])):
yield path
def breadth_first_search(paths):
if paths == Nil:
return
path = paths.head
node = path.head
if is_goal(node):
yield path
new_paths = Nil
for node1 in move_anyY(node):
if not member(node1, path):
new_paths = Cons(Cons(node1, path), new_paths)
if new_paths != Nil:
paths1 = append(paths.tail, new_paths)
else:
paths1 = paths.tail
for path in breadth_first_search(paths1):
yield path
graph = dict(A=["B", "E", "F"],
B=["C"], F=["C"],
C=["D"],
D=["E"])
def move_anyY(x):
# zavisi na resenem problemu
if x in graph:
for y in graph[x]:
yield y
# demonstracni vypis
if __name__ == "__main__":
print("Breadth-First Search")
print("Volani next(solution('A')): %s" % next(solution('A')))
print("Vsechna reseni solution('A'):")
for s in solution('A'):
print s
Breadth-First Search
Volani next(solution('A')): ['E', 'A']
Vsechna reseni solution('A'):
['E', 'A']
['E', 'D', 'C', 'F', 'A']
['E', 'D', 'C', 'B', 'A']
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