Incorrect tests for minimum spanning tree kruskal

[brecbor]

In some tests for minimum spanning tree kruskal directed instead of undirected graph is given.

[matejm]

Prim's algorithm fails on this test, edges are not directed.

g = {{}, {{0, 1}}, {{0, 1}}};
EXPECT_EQ(2, sum_of_paths_minimum_spanning_tree_prim(g));

Mabye sort vertices of an edge when pushing to priority queue?

[brecbor]

This graph is directed and that's why the algorithm fails