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_listdef 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)] = valif __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 itertoolsimport reimport mathdef combination(lst):  #全排序  lists=[]  liter=itertools.permutations(lst)  for lts in list(liter):    lt=''.join(lts)    lists.append(lt)  return listsdef 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 coordinatesdef 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 lstdef 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 wayif __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()