public void HasConnection()
{
// Arrange
var myGraph = new MatrixGraph(GraphTypes.Directed, 15);
{
myGraph.AddEdge(0, 1);
myGraph.AddEdge(0, 2);
myGraph.AddEdge(1, 9);
myGraph.AddEdge(1, 2);
myGraph.AddEdge(1, 3);
myGraph.AddEdge(1, 11);
myGraph.AddEdge(11, 9);
myGraph.AddEdge(2, 1);
myGraph.AddEdge(3, 4);
myGraph.AddEdge(3, 8);
myGraph.AddEdge(4, 10);
myGraph.AddEdge(4, 3);
myGraph.AddEdge(4, 5);
myGraph.AddEdge(10, 7);
myGraph.AddEdge(10, 4);
myGraph.AddEdge(7, 6);
myGraph.AddEdge(6, 7);
myGraph.AddEdge(5, 6);
myGraph.AddEdge(5, 2);
myGraph.AddEdge(8, 13);
myGraph.AddEdge(13, 14);
}
var graphMatrix = myGraph.GetGraphRepresentation();
// Practice
bool HasRoute(int node1, int node2)
{
var keepGoing = true;
var vertices = graphMatrix.GetLength(0);
var seachVisited = new int[vertices];
var bfsOrder1 = new Queue <int>(vertices);
bfsOrder1.Enqueue(node1);
var bfsOrder2 = new Queue <int>(vertices);
bfsOrder2.Enqueue(node2);
bool HasVisited(int node, int nodeIndex) =>
(seachVisited[node] & (1 << nodeIndex)) != 0;
while (keepGoing)
{
keepGoing = bfsOrder1.TryDequeue(out int node);
if (keepGoing)
{
for (byte i = 0; i < vertices; i++)
{
if (graphMatrix[node, i] == 1 && !HasVisited(i, 1))
{
bfsOrder1.Enqueue(i);
seachVisited[i] = seachVisited[i] | 1 << 1;
if (HasVisited(i, 2))
{
return(true);
}
}
}
}
keepGoing = bfsOrder2.TryDequeue(out node);
if (keepGoing)
{
for (byte i = 0; i < vertices; i++)
{
if (graphMatrix[node, i] == 1 && !HasVisited(i, 2))
{
bfsOrder2.Enqueue(i);
seachVisited[i] = seachVisited[i] | 1 << 2;
if (HasVisited(i, 1))
{
return(true);
}
}
}
}
}
return(false);
}
Assert.True(HasRoute(2, 10));
Assert.False(HasRoute(11, 8));
}
