public void TopologicalSort_Test()
{
var G = new Digraph(4);
G.AddEdge(3, 2);
G.AddEdge(3, 1);
G.AddEdge(1, 0);
G.AddEdge(2, 0);
var DFO = new TopologicalSort(G);
var actual = new List <int>(DFO.GetTopologicalySorted());
Assert.AreEqual(3, actual[0]);
Assert.AreEqual(0, actual[3]);
}