#!/usr/bin/env python
# encoding=utf-8 (pep 0263)
from linked_lists import Cons, Nil
def solution(node):
for path in depth_first_search(node, 999):
yield path
def depth_first_search(start_node, max_depth):
paths = [(Cons(start_node, Nil), max_depth)] # pouzijeme pythonovsky seznam jako LIFO
while len(paths) > 0:
path, remaining_depth = paths.pop()
node = path.head
if is_goal(node):
yield path
if remaining_depth > 0:
for node1 in move_anyY(node):
paths.append((Cons(node1, path), remaining_depth-1))
def is_goal(x):
# zavisi na resenem problemu
return x == "E"
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("Depth-First Search")
print("Volani next(solution('A')) : %s" % next(solution('A')))
print("Volani next(depth_first_search('A', 3)) : %s" % \
next(depth_first_search('A', 3)))
print("Volani next(depth_first_search('A', 4)) : %s" % \
next(depth_first_search('A', 4)))
Depth-First Search
Volani next(solution('A')) : ['E', 'D', 'C', 'F', 'A']
Volani next(depth_first_search('A', 3)) : ['E', 'A']
Volani next(depth_first_search('A', 4)) : ['E', 'D', 'C', 'F', 'A']
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