如何更快地找到与给定节点的平均距离最小的节点？

Question

我试图找到到给定节点的距离最短的节点，这就是我尝试过的。

import networkx as nx

G = nx.read_gpickle("Database/Pickle/test.gpickle")

targetcount = dict() #store number of reach to given node.
targetdistance = dict() #sum of distance to all of given node.

givennode = ['car', 'home', 'man']

#step1,find node that have path to givennode and store distance in dictionary 
#by using single_source_dijkstra_path_length()
for source in givennode:
    reachnode = nx.single_source_dijkstra_path_length(G, source, weight='cost')

    #than store target node and distance from reachnode variable.
    for target in reachnode:
        if target in targetcount:
            targetcount[target] += 1
            targetdistance[target] += reachnode[target]
        else:
            targetcount[target] = 1
            targetdistance[target] = reachnode[target]

minaverage = 999999999.99
finalword = ''

#step2, find average distance only node that can reach to all of given word.
for target in targetcount:
    #if node have reach number equal to givennode amount.
    if targetcount[target] == len(givennode):
        averagedistance = targetdistance[target] / len(givennode)
        if averagedistance < minaverage:
            minaverage = averagedistance
            finalword = target

print("Min average distance word :"+finalword)

通过执行这两个步骤，此代码大约需要9秒钟。

步骤1：查找从给定节点可以到达的节点，并存储到字典的距离。

第2步：通过仅计算可以到达所有给定节点的路径的节点，找到到给定节点的最小最小平均距离。

因此，有什么建议或其他方法可以更快地找到给定节点的最小平均距离。

谢谢