private static int[,] CreateWeightedAdjacencyMatrix(Adjacency adj)
{
var dims = adj.n;
var adjancencies = new int[dims, dims];
for (var i = 0; i < dims; i++)
{
for (var j = 0; j < dims; j++)
{
adjancencies[i, j] = adj.getWeight(i, j);
if (!adj.getElementAt(i, j))
{
adjancencies[i, j] = int.MaxValue;
}
}
}
return(adjancencies);
}
public static Pair[] KruskalMst(int n, Adjacency adjacency)
{
int i, j, k, l, m, u, v;
int ULength, count = 0;
var U = new int[n];
var SLength = new int[n];
var S = new int[n, n];
var A = new Pair[n * n];
var aLength = 0;
for (v = 0; v < n; v++)
{
SLength[v] = 1;
S[v, 0] = v;
}
for (u = 0; u < n - 1; u++)
{
for (v = u + 1; v < n; v++)
{
if (adjacency.getElementAt(u, v))
{
count++;
}
}
}
var edges = new Edge[count];
for (i = 0; i < count; i++)
{
edges[i] = new Edge();
}
for (i = u = 0; u < n - 1; u++)
{
for (v = u + 1; v < n; v++)
{
if (!adjacency.getElementAt(u, v))
{
continue;
}
edges[i].U = u;
edges[i].V = v;
edges[i++].Weight = adjacency.getWeight(u, v);
}
}
QuickSort(0, count - 1, aLength, edges);
for (i = 0; i < count; i++)
{
int jIndex = -1, lIndex = -1;
u = edges[i].U;
v = edges[i].V;
bool uFound;
for (uFound = false, j = 0; !uFound && j < n; j++)
{
for (k = 0; !uFound && k < SLength[j]; k++)
{
uFound = u == S[j, k];
if (uFound)
{
jIndex = j;
}
}
}
bool vFound;
for (vFound = false, l = 0; !vFound && l < n; l++)
{
for (m = 0; !vFound && m < SLength[l]; m++)
{
vFound = v == S[l, m];
if (vFound)
{
lIndex = l;
}
}
}
if (jIndex == lIndex)
{
continue;
}
var pair = new Pair(u, v);
for (j = 0; j < aLength; j++)
{
if (A[j].Equals(pair))
{
break;
}
}
if (j == aLength)
{
A[aLength++] = pair;
}
ULength = SLength[jIndex];
for (u = 0; u < ULength; u++)
{
U[u] = S[jIndex, u];
}
for (u = 0; u < SLength[lIndex]; u++)
{
v = S[lIndex, u];
for (vFound = false, j = 0; j < ULength; j++)
{
vFound = v == U[j];
}
if (!vFound)
{
U[ULength++] = v;
}
}
SLength[jIndex] = ULength;
for (j = 0; j < ULength; j++)
{
S[jIndex, j] = U[j];
}
SLength[lIndex] = 0;
}
return(A);
}
public static void CalculateAndPrintKruskalMst(int n, Adjacency adjacency, out Pair[] pairs)
{
pairs = KruskalMst(n, adjacency);
PrintKruskalMst(pairs);
}
