public static Tuple <double, List <edges> > prim_edit(List <int> x)
{
int n = x.Count();
List <bool> vis = new List <bool>(new bool[n]); // intalize it with zeros
double mst_cost = 0;
List <edges> e = new List <edges>(n - 1);
PriorityQueue <edges> q = new PriorityQueue <edges>();
float[] arr = new float[n];
for (int i = 0; i < n; i++)
{
arr[i] = float.MaxValue;
}
q.Enqueue(new edges(-1, 0, 0)); // intialiy
while (q.Count() > 0)
{
edges ee = q.Dequeue(); //O(1)
if (vis[ee.to] == true) // O(1)
{
continue; // O(1)
}
vis[ee.to] = true; // O(1)
mst_cost += (float)ee.we; // O(1)
if (ee.to != 0) // to not push new edges(-1, 0, 0) the initial edge" // O(1)
{
e.Add(ee); // O(1)
}
// loop throgh all list consider it fully connected
for (int j = 0; j < n; j++) // O(V) (V number of vertices in graph)
{
if (j == ee.to || vis[j] == true)
{
continue;
}
int r1 = (x[ee.to] >> 16) & 0xFF; //O(1)
int g1 = (x[ee.to] >> 8) & 0xFF; //O(1)
int b1 = x[ee.to] & 0xFF; //O(1)
int r2 = (x[j] >> 16) & 0xFF; //O(1)
int g2 = (x[j] >> 8) & 0xFF; //O(1)
int b2 = x[j] & 0xFF; //O(1)
double w = Math.Sqrt((r1 - r2) * (r1 - r2) + (g1 - g2) * (g1 - g2) + (b1 - b2) * (b1 - b2)); // O(1)
if (arr[j] > w)
{
arr[j] = (float)w;
}
else // (j=ee.to) if i have smaller weight to that edge don't push it in queue
{
continue;
}
q.Enqueue(new edges(ee.to, j, w)); //O(log(V)) (V number of vertices in graph)
}
}
return(new Tuple <double, List <edges> >(mst_cost, e));
}
public static Tuple <double, List <edges> > prim_edit(List <int> x)
{
int n = x.Count();
List <bool> vis = new List <bool>(new bool[n]); // intalize it with zeros
double mst_cost = 0;
List <edges> e = new List <edges>(n - 1);
PriorityQueue <edges> q = new PriorityQueue <edges>();
float[] arr = new float[n];
for (int i = 0; i < n; i++)
{
arr[i] = float.MaxValue;
}
q.Enqueue(new edges(-1, 0, 0)); // intialiy
int y = n;
while (q.Count() > 0)
{
edges ee = new edges(q.Peek().from, q.Peek().to, q.Peek().we);
q.Dequeue();
if (vis[ee.to] == true) // if (to) visited continue
{
continue;
}
vis[ee.to] = true;
mst_cost += (float)ee.we;
y--;
if (ee.to != 0) // not first "vertix"
{
e.Add(ee);
}
if (y == 0)
{
return(new Tuple <double, List <edges> >(mst_cost, e));
}
// loop throgh all list consider it fully connected
for (int j = 0; j < n; j++) // O(V) n number of nodes graph
{
if (j == ee.to || vis[j] == true)
{
continue;
}
int r1 = (x[ee.to] >> 16) & 0xFF;
int g1 = (x[ee.to] >> 8) & 0xFF;
int b1 = x[ee.to] & 0xFF;
int r2 = (x[j] >> 16) & 0xFF;
int g2 = (x[j] >> 8) & 0xFF;
int b2 = x[j] & 0xFF;
double w = Math.Sqrt((r1 - r2) * (r1 - r2) + (g1 - g2) * (g1 - g2) + (b1 - b2) * (b1 - b2)); // O(1)
if (arr[j] > w)
{
arr[j] = (float)w;
}
else // (j=ee.to) if i have smaller weight to that edge don't push it in queue
{
continue;
}
q.Enqueue(new edges(ee.to, j, w));
}
}
//for (int i = 0; i < n; i++)
//{
// MessageBox.Show("from=" + e[i].from.ToString());
// MessageBox.Show("to=" + e[i].to.ToString());
//}
return(new Tuple <double, List <edges> >(mst_cost, e));
}
