示例#1
0
文件: State.cs 项目: joshbcondie/TSP
        // Copy constructor for making children (Josh)
        // Reduces matrix based on whether edge is included
        // Adds state to queue
        public State(State parent, Boolean include, int from, int to)
        {
            matrix = (double[,])parent.matrix.Clone();
            route = new ArrayList(parent.route);
            visited = new ArrayList(parent.visited);
            bound = parent.bound;
            this.parent = parent;
            depth = parent.depth + 1;

            if (include)
            {
                bound += matrix[from, to];
                pathsLeft = parent.pathsLeft - 1;

                visited.Add(from);
                visited.Add(to);

                for (int i = 0; i < cityCount; i++)
                {
                    matrix[from, i] = double.PositiveInfinity;
                    matrix[i, to] = double.PositiveInfinity;
                }

                // If there's more than one path left, delete paths to used vertices (Josh)
                if (pathsLeft > 2)
                {
                    for (int i = 0; i < visited.Count; i++)
                    {
                        matrix[to, (int)visited[i]] = double.PositiveInfinity;
                        // Shouldn't be necessary, but who knows?
                        matrix[(int)visited[i], from] = double.PositiveInfinity;
                    }
                }
                else if (pathsLeft == 2)
                {
                    //this should keep the path from the final city back to the first one
                    for (int i = 1; i < visited.Count; i++)
                    {
                        matrix[to, (int)visited[i]] = double.PositiveInfinity;
                        // Shouldn't be necessary, but who knows?
                        matrix[(int)visited[i], from] = double.PositiveInfinity;
                    }
                }
                matrix[to, from] = double.PositiveInfinity;
            }
            else
            {
                matrix[from, to] = double.PositiveInfinity;
                pathsLeft = parent.pathsLeft;
            }

            reduceMatrix();

            // set BSSF if necessary (Josh)

            // If not, set BSSF if necessary (Josh)
            if (pathsLeft == 1)
            {
                for (int i = 0; i < cityCount; i++)
                {
                    for (int j = 0; j < cityCount; j++)
                    {
                        if (matrix[i, j] != double.PositiveInfinity)
                        {
                            includeChild = new State(this, true, i, j);
                            Console.WriteLine("Found solution");
                            for (int k = 0; k < includeChild.visited.Count; k++)
                            {
                                Console.WriteLine(includeChild.visited[k]);
                            }
                            if (includeChild.bound < BSSF.bound)
                            {
                                // Calculate route from visited nodes
                                includeChild.calculateRoute();
                                BSSF = includeChild;
                                // Prune states starting with root
                                root.prune();
                            }
                            else
                            {
                                return;
                            }
                        }
                    }
                }
            }

            // Add to queue
            if (pathsLeft > 0 && bound < BSSF.bound)
            {
                queue.Enqueue(this, Priority);
            }
        }