Question

我正在尝试编码的是我要求找到最少数量的设施，每个设施都位于数据集中的一个城市。
数据集在4个子列表的列表中设置如下。第一个列表是城市和州，下一个列表是坐标，下一个是人口，最后是里程。我只担心城市和州以及每个城市之间的里程数。数据的示例可能如下所示：（这些数字按顺序排列。）

data = [['Miami FL', 'Fort Meyers FL', 'Oakland CA', 'New York City NY'],
[[213, 124],[643,234],[754,652],[453,734]],[25345,56782,74563,234755],
[[0, 200, 2000, 1000],[200, 0, 1900, 950],[2000,1900,0,2500],[1000,950,2500]]

设定里程数，即城市的指数是彼此之间的距离。

data[3][0] = [0, 200, 2000, 1000] #Miami's distances from other cities
data[3][0][0] = 0 #how far away miami is from it self
data[3][0][1] = 200 #how far away Miami is from Fort Meyers
data[3][2][1] = 1900 how far away Oakland is from Fort Meyers

您获得半径为r（以英里为单位）并要求找到最少的数字设施，每个设施位于数据集中的128个城市之一，这样数据集中的128个城市中的每一个都距离某个设施不到r里程。返回的设施应按字母顺序排列。

我必须使用布尔列表来检查城市是否已被服务。

使用此算法

Greedy Algorithm for facility location
1. Initially all cities are unserved.
2. while there are cities that are unserved:
3. Pick a city c that "serves" the most unserved cities.
4. Mark the city c and all cities within r miles of c as served

这是我到目前为止所做的：

def locateFacilites(data, r):
    print data
    #creating list served list that has values of all False
    served = [False for x in range(128)]
    #all True list 
    complete = [True for x in range(128)]

    finalListOfFacilities = []
    beenServed = 0
    while served != complete:


        #looping over names of cities
        for index, c in enumerate(data[0]):

            if served[index] == False:
                #if unserved find the list of nearby cities
                listOfCities = nearbyCities(data[0][index], r, data)
                unservedList = []
                #condenses list to all false
                unservedList = cityUnservedList(listOfCities, data, served, unservedList)
                print len(unservedList)
                #Looping through cities to change them to be served
                if len(unservedList) > beenServed:
                    served = FalseToTrueList(unservedList, data, served)

                if len(unservedList) > beenServed:

                    finalListOfFacilities.append(c)
                    beenServed = len(unservedList)
    return finalListOfFacilities

#this function was given.  getDistance returns the distance from one city to another
def nearbyCities(city, r, data):
    listOfCities = []
    for i in data[0]:
        if getDistance(city, i, data) <=r:
            listOfCities.append(i)

    return sorted(listOfCities)

def cityUnservedList(listOfCities, data, served, unservedList):
    for city in listOfCities:
        i = data[0].index(city)
        if served[i] == False:
            unservedList.append(city)
    return unservedList

#converts cities that are false to true if unservedList is greater than beenServed
def FalseToTrueList(unservedList, data, served):        
    for city in unservedList:
        i = data[0].index(city)
        served[i] = True    
    return served

我相信我已经接近了，但是我遇到了运行时错误（无限循环）。有人可以指出我做错了什么或者建议去哪儿去？

找到给定半径的最少量设施

0 个答案: