private bool AllSameDirectionCycle(LinkedList <EdgeInfo> cycle, out EdgeInfo edgeInfoBad1, out EdgeInfo edgeInfoBad2, out EdgeInfo EdgeInfoLastIndex)
{
int direction = 0;
bool result = true;
var cycleArray = cycle.ToArray();
edgeInfoBad1 = null;
edgeInfoBad2 = null;
EdgeInfoLastIndex = cycleArray[0];
for (int i = 0; i < cycleArray.Length - 1; i++)
{
if (EdgeInfoLastIndex.EdgeIndex < cycleArray[i].EdgeIndex)
{
EdgeInfoLastIndex = cycleArray[i];
}
//if ( cycle[i,0] == cycle[i+1,0] )
//{
// result = false;
//}
if (cycleArray[i].Vertex2 == cycleArray[i + 1].Vertex2)
{
edgeInfoBad1 = cycleArray[i];
edgeInfoBad2 = cycleArray[i + 1];
result = false; // si hay uno con tipo x->y == w <-z es por existe uno con tipo y <-x == w -> z y son únicos
}
}
if (EdgeInfoLastIndex.EdgeIndex < cycleArray[cycleArray.Length - 1].EdgeIndex)
{
EdgeInfoLastIndex = cycleArray[cycleArray.Length - 1];
}
if (cycleArray[cycleArray.Length - 1].Vertex2 == cycleArray[0].Vertex2)
{
edgeInfoBad1 = cycleArray[cycleArray.Length - 1];
edgeInfoBad2 = cycleArray[0];
result = false; // si hay uno con tipo x->y == w <-z es por existe uno con tipo y <-x == w -> z y son únicos
}
return(result);
}
public int[] FindRedundantDirectedConnection(int[,] edges)
{
int lastVertex = -1;
for (int i = 0; i < edges.GetLength(0); i++)
{
if (edges[i, 0] > lastVertex)
{
lastVertex = edges[i, 0];
}
if (edges[i, 1] > lastVertex)
{
lastVertex = edges[i, 1];
}
if (edges[i, 0] == edges[i, 1])
{
return new int[] { edges[i, 0], edges[i, 1] }
}
;
}
Dictionary <int, int> dictEdges = new Dictionary <int, int>(edges.GetLength(0) * 2);
int[,] edgesBig = new int[edges.GetLength(0) * 2, 2];
for (int i = 0; i < edges.GetLength(0); i++)
{
dictEdges.Add(i, i);
dictEdges.Add(edges.GetLength(0) + i, i);
edgesBig[i, 0] = edges[i, 0];
edgesBig[i, 1] = lastVertex + 1 + i;
edgesBig[edges.GetLength(0) + i, 0] = lastVertex + 1 + i;
edgesBig[edges.GetLength(0) + i, 1] = edges[i, 1];
}
Graph graph = new Graph(edgesBig, true, lastVertex + edges.Length, true);
bool hasFather;
int fatherVertex;
int childVertex;
var cycle = graph.DFSGetFirstCycle(out hasFather, out fatherVertex, out childVertex);
if (hasFather)
{
EdgeInfo edgeInfoBad1 = null;
EdgeInfo edgeInfoBad2 = null;
EdgeInfo EdgeInfoLastIndex = null;
if (AllSameDirectionCycle(cycle, out edgeInfoBad1, out edgeInfoBad2, out EdgeInfoLastIndex))
{
foreach (var edge in cycle)
{
if (edge.Vertex2 == childVertex)
{
int index = dictEdges[edge.EdgeIndex];
return(new int[2] {
edges[index, 0], edges[index, 1]
});
//return new int[2] { edge.Vertex1, edge.Vertex2 };
}
}
}
else
{
var edgeInfoMax = edgeInfoBad1;
if (edgeInfoBad1.EdgeIndex < edgeInfoBad2.EdgeIndex)
{
edgeInfoMax = edgeInfoBad2;
}
int index = dictEdges[edgeInfoMax.EdgeIndex];
return(new int[2] {
edges[index, 0], edges[index, 1]
});
//return new int[2] { edgeInfoMax.Vertex1, edgeInfoMax.Vertex2 };
}
}
else
{
EdgeInfo edgeInfoBad1 = null;
EdgeInfo edgeInfoBad2 = null;
EdgeInfo EdgeInfoLastIndex = null;
if (AllSameDirectionCycle(cycle, out edgeInfoBad1, out edgeInfoBad2, out EdgeInfoLastIndex))
{
int index = dictEdges[EdgeInfoLastIndex.EdgeIndex];
return(new int[2] {
edges[index, 0], edges[index, 1]
});
//return new int[2] { EdgeInfoLastIndex.Vertex1, EdgeInfoLastIndex.Vertex2 };
}
else
{
var edgeInfoMax = edgeInfoBad1;
if (edgeInfoBad1.EdgeIndex < edgeInfoBad2.EdgeIndex)
{
edgeInfoMax = edgeInfoBad2;
}
int index = dictEdges[edgeInfoMax.EdgeIndex];
return(new int[2] {
edges[index, 0], edges[index, 1]
});
//return new int[2] { edgeInfoMax.Vertex1, edgeInfoMax.Vertex2 };
}
}
return(null);
}
