Dijstra算法的Python实现

#_*_coding=utf-8_*_import numpy as npmaxNum=1000000   #用一个大数表示无穷大def Dijkstra(G,S):    nV=len(G[0])    #初始化顶点访问标签    label=np.array([False]*nV)    label[S]=True    #初始化距离向量    Dis=np.array([maxNum]*5)    for i in range(nV):        Dis[i]=G[S][i]    Dis[S]=0    for i in range(nV):        u=minDis(G,label,Dis)        if u==nV:            break        if Dis[u]==maxNum:            continue        label[u]=True        for j in range(5):            if G[u][j]!=maxNum and Dis[j]>(Dis[u]+G[u][j]):                Dis[j]=Dis[u]+G[u][j]    return Disdef minDis(G,label,Dis):    u=0    nV=len(G[0])    #顺序查找第一个未访问顶点，全部访问则返回nV    while(u<nV and label[u]):        u+=1    #查找距离更小的未访问结点    l=range(u+1,nV,1)    for i in l:        if not label[i] and Dis[i]<Dis[u]:            u=i    return uG=np.array([[maxNum,7,6,maxNum,maxNum],            [7,maxNum,maxNum,3,4],            [6,maxNum,maxNum,maxNum,2],            [maxNum,3,maxNum,maxNum,1],            [maxNum,4,2,1,maxNum]])for i in range(len(G[0])):    print Dijkstra(G,i)>>> =============== RESTART: E:\DS&A\算法实现\Dijkstra\Dijkstra.py ===============[0 7 6 9 8][7 0 6 3 4][6 6 0 3 2][9 3 3 0 1][8 4 2 1 0]