图源点到各个点的最短路径（DIJ）

# -*- coding: cp936 -*-

import copy

MV = 0xFFFFFFFF

Vertexs = {0:'v0',1:'v1',2:'v2',3:'v3',4:'v4',5:'v5'}

Arcs = [[MV,MV,10,MV,30,100],[MV,MV,5,MV,MV,MV],[MV,MV,MV,50,MV,MV],\

        [MV,MV,MV,MV,MV,10],[MV,MV,MV,20,MV,MV],[MV,MV,MV,MV,MV,MV]]



#初始化源点到目标点的最短路径    

def init_dist(srcVertex):

    return Arcs[srcVertex]

#某个节点的最短路径

def findShortestPathToVertex(srcVertex, Vertex, dist, targetSet):

    temp = Arcs[srcVertex][Vertex]

    path = [srcVertex, Vertex]

    rslt = []

    

    for i in targetSet.keys():

        if MV != Arcs[i][Vertex] and i != srcVertex:

            if Arcs[i][Vertex] + dist[i] < temp:

                temp = Arcs[i][Vertex] + dist[i]

                path = copy.deepcopy(targetSet[i])

                path.append(Vertex)



    rslt.append(temp)

    rslt.append(path)

    return rslt



#从未获取最短路径的节点中找到一条最短路径的节点        

def findShortestPath(srcVertex, dist, targetSet):

    minValue = MV

    Vertex = -1

    

    for i in Vertexs.keys():

        if i not in targetSet.keys():

            path = findShortestPathToVertex(srcVertex, i, dist, targetSet)

            if path[0] < minValue:

                minValue = path[0]

                Vertex = i

                pathInfo = path[1]

                

    if -1 != Vertex:

        targetSet[Vertex] = pathInfo

        dist[Vertex] = minValue

            

def shortPath_DIJ(srcVertex):

    dist = init_dist(srcVertex)

    #targetSet = [srcVertex]

    targetSet = {srcVertex:[srcVertex]}



    for i in range(len(Vertexs) - 1):

        findShortestPath(srcVertex, dist, targetSet)



    print targetSet

    print dist

    

shortPath_DIJ(0)