/// <summary>
/// Алгоритм Джонсона. Сложность 0(V^2*lgV + VE), если Фибоначчиевая куча, или 0(VE*lgV).
/// Вычисление кратчайших путей между всеми парами вершин
/// </summary>
public string JohnsonAlgorithm()
{
Size += 1;
VerticesList.Add(new Vertex(Size));
Vertex curVertexFrom = VerticesList[Size - 1];
for (int i = 0; i < Size - 1; i++)
{
Vertex curVertexTo = VerticesList[i];
IncidentEdge curEdge = new IncidentEdge(curVertexTo, 0);
curVertexFrom.AdjacencyList.Add(curEdge);
}
if (BellmanFordAlgorithm(curVertexFrom) == false)
{
Console.WriteLine("Входной граф содержит цикл с отрицательным весом");
}
else
{
foreach (var vertex in VerticesList)
{
foreach (var incidentEdge in vertex.AdjacencyList)
{
incidentEdge.Weight = incidentEdge.Weight + vertex.Distance - incidentEdge.IncidentTo.Distance;
}
}
VerticesList.RemoveAt(Size - 1);
Size -= 1;
int[] Distances = new int[Size];
for (int i = 0; i < Size; i++)
{
Distances[i] = VerticesList[i].Distance;
}
int[,] matrix = new int[Size, Size];
for (int i = 0; i < Size; i++)
{
Dijkstra(VerticesList[i]);
for (int j = 0; j < Size; j++)
{
matrix[i, j] = VerticesList[j].Distance + Distances[j] - Distances[i];
}
}
StringBuilder output = new StringBuilder();
for (int i = 0; i < Size; i++)
{
for (int j = 0; j < Size; j++)
{
output.Append(matrix[i, j] + " ");
}
output.Append("\n");
}
Console.WriteLine(output);
return(output.ToString());
}
return(null);
}
public Graph(int size, string[] strs)
{
Size = size;
VerticesList = new List <Vertex>();
for (int i = 1; i <= Size; i++)
{
VerticesList.Add(new Vertex(i));
}
try
{
int curIndex = 0;
foreach (var str in strs)
{
Vertex curVertexFrom = VerticesList[curIndex];
var array = str.Split();
int length = array.Length;
if (!string.IsNullOrEmpty(str))
{
for (int i = 0; i < length; i++)
{
int intVar = int.Parse(array[i++]);
if (intVar > Size)
{
throw new Exception("The vertex is missing");
}
Vertex curVertexTo = VerticesList[intVar - 1];
intVar = int.Parse(array[i]);
IncidentEdge curEdge = new IncidentEdge(curVertexTo, intVar);
curVertexFrom.AdjacencyList.Add(curEdge);
}
}
curIndex += 1;
}
}
catch (Exception ex)
{
if (ex is NullReferenceException || ex is FormatException)
{
Console.WriteLine("String is empty (Graph)"); //throw new Exception("String is empty (Graph)");
}
else
{
throw new Exception(ex.Message);
}
}
}
