myGraph = mkGraph [(0, ()), (1, ()), (2, ())]
[(0, 1, (0, 2)), (0, 2, (1, 3)), (2, 1, (2, -2))] :: Gr () (Int, Int)
bfResult = bellmanFord snd 0 myGraph
myGraph = mkGraph [(0, ()), (1, ()), (2, ())]
[(0, 1, (0, 2)), (0, 2, (1, 3)), (2, 1, (2, -2))] :: Gr () (Int, Int)
bfResult = bellmanFord snd 0 myGraph