Algorithm to find the minimum spanning tree using Kruskal’s algorithm
Function takes an array of points, given as pairs of integer coordinates in the 'test_in' file. It constructs the graph of all point pairs, with the distance being the euclidean distance, and finds the minimum spanning tree, using Kruskal’s algorithm.
It returns the edges of the minimum spanning tree, given as pairs of vertex numbers. The minimum spanning tree creates a graph on the output with the x11 library functions.