public static int GetMaxShortestPath(int[][] matrix, int fromVertex)
{
matrix = MatrixMinimizer.GetMinimizedMatrix(matrix);
bool[] used = new bool[matrix.Length];
int usedCount = 0;
int[] distances = new int[matrix.Length];
Queue <int> vertexQueue = new Queue <int>();
for (int i = 0; i < matrix.Length; i++)
{
distances[i] = int.MaxValue;
used[i] = false;
vertexQueue.Enqueue(i);
}
distances[fromVertex] = 0;
while (vertexQueue.Count != 0)
{
int vertex = vertexQueue.Dequeue();
while (vertexQueue.Count != 0 && (used[vertex] || distances[vertex] == int.MaxValue))
{
vertex = vertexQueue.Dequeue();
}
used[vertex] = true;
usedCount++;
for (int i = 0; i < matrix[vertex].Length; i++)
{
int neighbor = i;
if (matrix[vertex][neighbor] == int.MaxValue)
{
continue;
}
int newDistance = distances[vertex] + matrix[vertex][neighbor];
if (!used[neighbor] && newDistance < distances[neighbor])
{
distances[neighbor] = newDistance;
vertexQueue.Enqueue(neighbor);
}
}
}
return(distances.Max());
}
public static (int, int) GetTheBestBaseVertexAndDistance(Graph graph)
{
int inf = int.MaxValue;
int[][] matrix = MatrixMinimizer.GetMinimizedMatrix(graph.Contiguity);
for (int k = 0; k < matrix.Length; k++)
{
for (int i = 0; i < matrix.Length; i++)
{
for (int j = 0; j < matrix.Length; j++)
{
if ((matrix[i][k] == inf || matrix[k][j] == inf) || (k == j || k == i))
{
continue;
}
if (matrix[i][j] > matrix[i][k] + matrix[k][j])
{
matrix[i][j] = matrix[i][k] + matrix[k][j];
}
}
}
}
int minVertex = int.MaxValue;
int minDistance = int.MaxValue;
for (int i = 0; i < matrix.Length; i++)
{
matrix[i][i] = 0; // to not get path from vertex to itself
int tempDistance = matrix[i].Max();
if (tempDistance < minDistance)
{
minDistance = tempDistance;
minVertex = i;
}
}
return(minVertex, minDistance);
}
