static OrientedGraph OrientedGraphGenerator(int noVertices, int noEdges)
{
HashSet <Edge> edges = new HashSet <Edge>();
var rand = new Random();
OrientedGraph g = new OrientedGraph();
for (int i = 0; i < noVertices; i++)
{
g.AddVertex();
}
for (int i = 0; i < noEdges; i++)
{
long weight = (long)rand.Next(1000000);
int a = rand.Next(100000);
int b = rand.Next(100000);
Edge e = new Edge(a, b, weight);
if (!edges.Contains(e))
{
g.AddEdge(a, b, weight);
edges.Add(e);
}
else
{
i--;
}
}
return(g);
}
/// <summary>
/// This is example program that reads CSV file containing dependencies
/// for installing different programs and outputs order in which
/// programs have to be installed so that no dependencies are missing
/// when programs are installed.
/// </summary>
public static void Main()
{
OrientedGraph og = new OrientedGraph();
// Read input data
string[] lines = System.IO.File.ReadAllLines("dependencies.csv");
// Assign index to every program (create pairing - name, index)
Dictionary <string, long> programs = new Dictionary <string, long>();
string [] names = new string[lines.Length];
int i = 0;
// Parse input, add vertices to graph and remember their indices
foreach (string line in lines)
{
string programName = line.Split(',')[0];
programs.Add(programName, i);
names[i] = programName;
og.AddVertex(i);
i++;
}
// Add edges to a graph
foreach (string line in lines)
{
string[] dependencies = line.Split(',');
for (int j = 1; j < dependencies.Length; j++)
{
long destination = programs[dependencies[j]];
long source = programs[dependencies[0]];
og.AddEdge(source, destination);
}
}
// Find topological ordering of dependencies
List <long> topoOrder = Toposort.TopologicalOrdering(ref og);
// Print order in which programs have to be installed
Console.WriteLine("Install in following order:");
for (int j = 0; j < topoOrder.Count; j++)
{
Console.Write(names[topoOrder[j]] + " ");
if (j + 1 < topoOrder.Count)
{
Console.Write("--> ");
}
}
Console.WriteLine();
}
OrientedGraph oriented()
{
OrientedGraph og = new OrientedGraph();
for (int i = 0; i < 7; i++)
{
og.AddVertex();
}
og.AddEdge(1, 2, 2);
og.AddEdge(1, 3, 1);
og.AddEdge(2, 3, 1);
og.AddEdge(1, 4, 4);
og.AddEdge(3, 6, 3);
og.AddEdge(4, 5, 3);
og.AddEdge(5, 6, 1);
return(og);
}
public void testSCCS()
{
OrientedGraph s = new OrientedGraph();
OrientedGraph og = oriented();
for (int i = 1; i < 9; i++)
{
s.AddVertex();
}
s.AddEdge(1, 2);
s.AddEdge(2, 3);
s.AddEdge(3, 1);
s.AddEdge(2, 4);
s.AddEdge(2, 5);
s.AddEdge(5, 6);
s.AddEdge(6, 7);
s.AddEdge(7, 5);
int [] correct = new int[] { 4, 3, 3, 3, 2, 1, 1, 1 };
int [] res = Scc.FindSCCS(s);
Assert.AreEqual(correct, res);
Assert.AreEqual(new int[] { 7, 6, 5, 4, 3, 2, 1 }, Scc.FindSCCS(og));
}
public void testAddRemoveEdgesVertices()
{
// Not oriented graph
Graph g = new Graph();
for (int i = 0; i < 6; i++)
{
g.AddVertex();
}
g.AddEdge(2, 3);
g.AddEdge(1, 3);
g.AddEdge(2, 5);
g.AddEdge(3, 5);
Assert.False(g.RemoveEdge(1, 2));
Assert.False(g.RemoveEdge(5, 1));
Assert.True(g.RemoveEdge(1, 3));
Assert.True(g.RemoveEdge(2, 5));
Assert.False(g.RemoveEdge(2, 5));
// Oriented graph
OrientedGraph og = new OrientedGraph();
for (int i = 0; i < 7; i++)
{
og.AddVertex();
}
og.AddEdge(1, 4, 2);
og.AddEdge(6, 1, 3);
og.AddEdge(1, 3, 3);
og.AddEdge(4, 6, 1);
og.AddEdge(6, 4, 2);
Assert.True(og.RemoveEdge(1, 4));
Assert.False(og.RemoveEdge(1, 4));
Assert.False(og.RemoveEdge(1, 6));
Assert.False(og.RemoveEdge(3, 1));
Assert.True(og.RemoveEdge(4, 6));
Assert.True(og.RemoveEdge(1, 3));
}
