Exemplo n.º 1
0
        /// <summary>
        /// Dijkstra algorithm
        /// </summary>
        /// <param name="sourceIndex">the source index of vertex</param>
        /// <param name="heap">the heap tha support priority queue</param>
        /// <returns>return the array that contains the minimal length from the source to all vertex</returns>
        public double[] Dijkstra(int sourceIndex, Heap <VertexNode> heap)
        {
            double[] result = new double[count];
            for (int i = 0; i < count; i++)
            {
                result[i] = maxDistance;
            }
            result[sourceIndex] = 0;
            GraphPriorityQueue queue = new GraphPriorityQueue(count, new BinaryHeap <VertexNode>(count));

            VertexNode[] vertexNodeArray = new VertexNode[count];
            for (int i = 0; i < count; i++)
            {
                vertexNodeArray[i] = new VertexNode(i, maxDistance);
            }
            queue.BuildHeap(vertexNodeArray);
            queue.ModifyVertexNode(sourceIndex, 0);
            while (queue.Count != 0)
            {
                VertexNode minNode = queue.ExtractMin();
                if (minNode.Length == maxDistance)
                {
                    break;
                }

                for (AdjEdgeNode edgeNode = nodes[minNode.Index].FirstEdge; edgeNode != null; edgeNode = edgeNode.Next)
                {
                    if (edgeNode.Length < maxDistance)
                    {
                        double newLength = minNode.Length + edgeNode.Length;
                        if (newLength < result[edgeNode.Index])
                        {
                            result[edgeNode.Index] = newLength;
                            queue.ModifyVertexNode(edgeNode.Index, newLength);
                        }
                    }
                }
            }
            return(result);
        }
Exemplo n.º 2
0
        /// <summary>
        /// Dijkstra algorithm
        /// </summary>
        /// <param name="sourceIndex">the source index of vertex</param>
        /// <param name="heap">the heap tha support priority queue</param>
        /// <returns>return the array that contains the minimal length from the source to all vertex</returns>
        public double[] Dijkstra(int sourceIndex, Heap <VertexNode> heap)
        {
            double[] result = new double[count];
            for (int i = 0; i < count; i++)
            {
                result[i] = maxDistance;
            }
            result[sourceIndex] = 0;
            GraphPriorityQueue queue = new GraphPriorityQueue(count, heap);

            VertexNode[] vertexNodeArray = new VertexNode[count];
            for (int i = 0; i < count; i++)
            {
                vertexNodeArray[i] = new VertexNode(i, maxDistance);
            }
            queue.BuildHeap(vertexNodeArray);
            queue.ModifyVertexNode(sourceIndex, 0);
            while (queue.Count != 0)
            {
                VertexNode minNode = queue.ExtractMin();
                if (minNode.Length == maxDistance)
                {
                    break;
                }
                for (int i = 0; i < count; i++)
                {
                    if (matrix[minNode.Index][i] < maxDistance)
                    {
                        double newLength = minNode.Length + matrix[minNode.Index][i];
                        if (newLength < result[i])
                        {
                            result[i] = newLength;
                            queue.ModifyVertexNode(i, newLength);
                        }
                    }
                }
            }
            return(result);
        }