static void Main(string[] args)
{
Console.WriteLine("DFS example:");
IGraph <char> graph = new Graph <char>();
var dfs = new DFS <char>();
var a = graph.AddVertex('A');
var b = graph.AddVertex('B');
var c = graph.AddVertex('C');
var d = graph.AddVertex('D');
var e = graph.AddVertex('E');
var f = graph.AddVertex('F');
var g = graph.AddVertex('G');
graph.AddEdge(a, b);
graph.AddEdge(a, d);
graph.AddEdge(a, f);
graph.AddEdge(f, d);
graph.AddEdge(f, c);
graph.AddEdge(d, c);
graph.AddEdge(d, e);
graph.AddEdge(d, g);
graph.AddEdge(e, g);
graph.AddEdge(c, g);
Console.Write("Iterative:");
dfs.DepthFirstSearchIterative(graph, a);
Console.Write("Recursive:");
dfs.DepthFirstSearchRecursive(graph, a);
}