python编写的最短路径算法

# -*-coding:utf-8 -*-
class DijkstraExtendPath():
  def __init__(self, node_map):
    self.node_map = node_map
    self.node_length = len(node_map)
    self.used_node_list = []
    self.collected_node_dict = {}
  def __call__(self, from_node, to_node):
    self.from_node = from_node
    self.to_node = to_node
    self._init_dijkstra()
    return self._format_path()
  def _init_dijkstra(self):
    self.used_node_list.append(self.from_node)
    self.collected_node_dict[self.from_node] = [0, -1]
    for index1, node1 in enumerate(self.node_map[self.from_node]):
      if node1:
        self.collected_node_dict[index1] = [node1, self.from_node]
    self._foreach_dijkstra()
  def _foreach_dijkstra(self):
    if len(self.used_node_list) == self.node_length - 1:
      return
    for key, val in self.collected_node_dict.items(): # 遍历已有权值节点
      if key not in self.used_node_list and key != to_node:
        self.used_node_list.append(key)
      else:
        continue
      for index1, node1 in enumerate(self.node_map[key]): # 对节点进行遍历
        # 如果节点在权值节点中并且权值大于新权值
        if node1 and index1 in self.collected_node_dict and self.collected_node_dict[index1][0] > node1 + val[0]:
          self.collected_node_dict[index1][0] = node1 + val[0] # 更新权值
          self.collected_node_dict[index1][1] = key
        elif node1 and index1 not in self.collected_node_dict:
          self.collected_node_dict[index1] = [node1 + val[0], key]
    self._foreach_dijkstra()
  def _format_path(self):
    node_list = []
    temp_node = self.to_node
    node_list.append((temp_node, self.collected_node_dict[temp_node][0]))
    while self.collected_node_dict[temp_node][1] != -1:
      temp_node = self.collected_node_dict[temp_node][1]
      node_list.append((temp_node, self.collected_node_dict[temp_node][0]))
    node_list.reverse()
    return node_list
def set_node_map(node_map, node, node_list):
  for x, y, val in node_list:
    node_map[node.index(x)][node.index(y)] = node_map[node.index(y)][node.index(x)] = val
if __name__ == "__main__":
  node = ['A', 'B', 'C', 'D', 'E', 'F', 'G']
  node_list = [('A', 'F', 9), ('A', 'B', 10), ('A', 'G', 15), ('B', 'F', 2),
         ('G', 'F', 3), ('G', 'E', 12), ('G', 'C', 10), ('C', 'E', 1),
         ('E', 'D', 7)]
  node_map = [[0 for val in xrange(len(node))] for val in xrange(len(node))]
  set_node_map(node_map, node, node_list)
  # A -->; D
  from_node = node.index('A')
  to_node = node.index('D')
  dijkstrapath = DijkstraPath(node_map)
  path = dijkstrapath(from_node, to_node)
  print path

<!-- lang: python -->
# -*- coding: utf-8 -*-
import itertools
import re
import math

def combination(lst):  #全排序
  lists=[]
  liter=itertools.permutations(lst)
  for lts in list(liter):
    lt=''.join(lts)
    lists.append(lt)
  return lists

def coord(lst):   #坐标输入
  coordinates=dict()
  print u'请输入坐标：（格式为A:7 17）'
  p=re.compile(r"\d+")
  for char in lst:
    str=raw_input(char+':')
    dot=p.findall(str)
    coordinates[char]=[dot[0],dot[1]]
  print coordinates
  return coordinates

def repeat(lst):  #删除重复组合
  for ilist in lst:
    for k in xrange(len(ilist)):
      st=(ilist[k:],ilist[:k])
      strs=''.join(st)
      for jlist in lst:
        if(cmp(strs,jlist)==0):
          lst.remove(jlist)
    for k in xrange(len(ilist)):
      st=(ilist[k:],ilist[:k])
      strs=''.join(st)
      for jlist in lst:
        if(cmp(strs[::-1],jlist)==0):
          lst.remove(jlist)
    lst.append(ilist)
    print lst
  return lst

def count(lst,coordinates): #计算各路径
  way=dict()
  for str in lst:
    str=str+str[:1]
    length=0
    for i in range(len(str)-1):
      x=abs( float(coordinates[str[i]][0]) - float(coordinates[str[i+1]][0]) )
      y=abs( float(coordinates[ str[i] ][1]) - float(coordinates[ str[i+1] ][1]) )
      length+=math.sqrt(x**2+y**2)
    way[str[:len(str)-1]]=length
  return way

if __name__ =="__main__":
  print u'请输入图节点：'
  rlist=list(raw_input())
  coordinates=coord(rlist)

  list_directive = combination(rlist)
#  print "有方向完全图所有路径为:",list_directive
#  for it in list_directive:
#    print it
  print u'有方向完全图所有路径总数:',len(list_directive),"\n"

#无方向完全图
  list_directive=repeat(list_directive)
  list_directive=repeat(list_directive)
#  print "无方向完全图所有路径为:",list_directive
  print u'无方向完全图所有路径为:'
  for it in list_directive:
    print it
  print u'无方向完全图所有路径总数:',len(list_directive)

  ways=count(list_directive,coordinates)
  print u'路径排序如下：'
  for dstr in sorted(ways.iteritems(), key=lambda d:d[1], reverse = False ):
    print dstr
  raw_input()