Esempio n. 1
0
        private static float CalcWeight(VertexParent V1, VertexParent V2)
        {
            byte red1, red2;
            byte green1, green2;
            byte blue1, blue2;

            red1   = (byte)(V1.V >> 16);
            red2   = (byte)(V2.V >> 16);
            green1 = (byte)(V1.V >> 8);
            green2 = (byte)(V2.V >> 8);
            blue1  = (byte)(V1.V);
            blue2  = (byte)(V2.V);
            return((float)Math.Sqrt((red2 - red1) * (red2 - red1) + (green2 - green1) * (green2 - green1) + (blue2 - blue1) * (blue2 - blue1)));
        }
Esempio n. 2
0
        public static List <Edge> PrimMST(List <int> D)
        {
            List <Edge> MSTList = new List <Edge>();
            // final list contains the MST

            FastPriorityQueue <VertexParent> FP = new FastPriorityQueue <VertexParent>(D.Count);

            // Priority queue sorts the priority of edges' weights each time .

            VertexParent [] VP = new VertexParent[D.Count];
            // array holding each node and it's parent node.

            VP[0] = new VertexParent(D[0], null); // initializing the first node in the MST.

            FP.Enqueue(VP[0], 0);                 // inserting the first node into the priority queue.

            float w;

            for (int i = 1; i < D.Count; i++)
            {
                // intializing all the weights with OO value.
                VP[i] = new VertexParent(D[i], null);
                FP.Enqueue(VP[i], int.MaxValue);
            }
            while (FP.Count != 0)
            {
                VertexParent Top = FP.Dequeue(); // get the minimum priority
                if (Top.P != null)               // if it is not the starting node.
                {
                    Edge E;
                    E.V1     = Top.V;
                    E.V2     = (int)(Top.P);
                    E.Weight = (float)(Top.Priority);
                    MSTList.Add(E);            // add the minimum weight to the MST.
                }
                foreach (var unit in FP)       // modify the priority each time .
                {
                    w = CalcWeight(unit, Top); // calculates the weight between the current node and the top node.
                    if (w < unit.Priority)
                    {
                        unit.P = Top.V;
                        FP.UpdatePriority(unit, w);
                    }
                }
            }

            return(MSTList);
        }