如何找到在二维平面上连接一组坐标的最小生成树？

Question

I have already coded Prim's algorithm in python, but this takes as inputs a weighted graph with nodes and edges, which is not what i have.

How do I convert the given co-ordinates in to a graph such that the program can accept the inputs, and i get a meaningful answer?

Answer 1

This is where the concept of Classes shall prove useful.

Create a Coordinate class and store your nodes and edges as instances of that class. Add a __sub__ method to the Coordinate class so as to get the Weights (Distances or whatever you want weights to be.) between two Coordinates.

Example :-

class Coordinate:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def __sub__(self, other):
        return (self.x - other.x)**2 + (self.y - other.y)**2
        # No need to square root to compare distances.

Now you can easily create an Adjacency Map/List as per your convenience and also find the corresponding weights and use your algorithm.