TSP使用python

我已经做了功课,想出解决旅行者推销员问题的python程序.在课堂上,他们解释了它应该如何工作并展示了一个例子.

path_map = [[0,10,15,20],
        [5,0,9,10],
        [6,13,0,12],
        [8,8,9,0]]

这是一个示例地图
我认为这是流行的问题,我可以找到解决这个问题的算法在互联网上.但我不能.我试过自己的版本.但我失败了.任何帮助将不胜感激.
这是我到目前为止所拥有的

class TSP:

def __init__(self, init, path_map):
    self.init = init
    self.cost = 0
    self.path_map = path_map
    self.vertices = [i for i in range(1,len(path_map)+1)]

def min_path(self, start):
    if not self.vertices:
        return self.path_map[start-1][init-1]
    else:
        m = [i for i in range(len(self.vertices)+1)]
        i=0
        for v in self.vertices:
            tv = self.vertices.pop(v-1)
            m[i]=self.cost + self.min_path(v)
            self.vertices.insert(v-1,tv)
            i = i + 1
        self.cost = self.cost + min(m)

    return cost `

我得到的,当我尝试运行它时：

>>> t = TSP(1,path_map)
>>> t.min_path(1)
Traceback (most recent call last):
  File "<pyshell#54>", line 1, in <module>
    t.min_path(1)
  File "/home/wanhrust/python/TSP.py", line 42, in min_path
    m[i]=self.cost + self.min_path(v)
  File "/home/wanhrust/python/TSP.py", line 42, in min_path
    m[i]=self.cost + self.min_path(v)
  File "/home/wanhrust/python/TSP.py", line 42, in min_path
    m[i]=self.cost + self.min_path(v)
  File "/home/wanhrust/python/TSP.py", line 41, in min_path
    tv = self.vertices.pop(v)
IndexError: pop index out of range

解决方法:

>生成大量随机解决方案.
>按长度排序这些解决方案.
>删除最差的50％
>以某种方式将最好的50％相互结合(将它们拼接在一起)
>转到2.

重复此操作,直到找到稳定的解决方案.它(几乎可以肯定)不会是最优的,但它会比随机好得多.

标签：python,traveling-salesman
来源： https://codeday.me/bug/20190709/1412250.html