Exemple #1
0
        private async void SimulatedAnnealingLocalSearchTSP()
        {
            (int, int)switchPair;
            Cost        = TSPCost(CityOrder);
            Temperature = 100d;
            double     deltaCost, bestCost = double.MaxValue;
            List <int> bestAnswer = null;

            while (Temperature >= .5d)
            {
                for (int i = 0; i < 0x0000FFFF; i++)
                {
                    //SA
                    Cost = TSPCost(CityOrder);
                    int seperateStart = Random.Next(0, N - 1);
                    int seperateEnd   = Random.Next(seperateStart + 1, N);
                    CityOrder.Reverse(seperateStart, seperateEnd - seperateStart);
                    switchPair = RandomPair();
                    SwapPair(CityOrder, switchPair);

                    deltaCost = TSPCost(CityOrder) - Cost;
                    if (deltaCost >= 0 && (Random.NextDouble() >= Math.Exp(-(deltaCost / Temperature))))
                    {
                        SwapPair(CityOrder, switchPair);
                        CityOrder.Reverse(seperateStart, seperateEnd - seperateStart);
                    }

                    if (Cost < bestCost)
                    {
                        bestCost   = Cost;
                        bestAnswer = new List <int>(CityOrder);
                    }

                    if (DisplayEveryStep)
                    {
                        await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => {
                            DisplayRoute(TSPCanvas);
                            Bindings.Update();
                        });
                    }
                }
                await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => {
                    DisplayRoute(TSPCanvas);
                    Bindings.Update();
                });

                Temperature *= 0.99;
            }
            Cost      = bestCost;
            CityOrder = new List <int>(bestAnswer);
            await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => {
                DisplayRoute(TSPCanvas);
                Bindings.Update();
                TSPCostTextBlock.Text += " Done!";
            });
        }
Exemple #2
0
        private async void LocalSearchTSP()
        {
            Cost = TSPCost(CityOrder);
            double     minCost, currentCost;
            List <int> bestNeighbour = new List <int>();

            while (true)
            {
                minCost = double.MaxValue;
                bestNeighbour.Clear();

                for (int i = 0; i < N; i++)
                {
                    int seperateStart = Random.Next(0, N - 1);
                    int seperateEnd   = Random.Next(seperateStart + 1, N);
                    CityOrder.Reverse(seperateStart, seperateEnd - seperateStart);
                    currentCost = TSPCost(CityOrder);
                    if (currentCost < minCost)
                    {
                        minCost       = currentCost;
                        bestNeighbour = CityOrder.ToList();
                    }
                    CityOrder.Reverse(seperateStart, seperateEnd - seperateStart);
                }

                ////Random switch four
                //for (int i = 0; i < N * N; i++) {
                //    var switchPair1 = RandomPair();
                //    var switchPair2 = RandomPair();
                //    SwapPair(CityOrder, switchPair1);
                //    SwapPair(CityOrder, switchPair2);
                //    currentCost = TSPCost(CityOrder);
                //    if (currentCost < minCost) {
                //        minCost = currentCost;
                //        bestNeighbour = CityOrder.ToList();
                //    }
                //    SwapPair(CityOrder, switchPair2);
                //    SwapPair(CityOrder, switchPair1);
                //}

                //Switch two
                for (int i = 0; i < N; i++)
                {
                    for (int j = i + 1; j < N; j++)
                    {
                        SwapPair(CityOrder, (i, j));
                        currentCost = TSPCost(CityOrder);
                        if (currentCost < minCost)
                        {
                            minCost       = currentCost;
                            bestNeighbour = CityOrder.ToList();
                        }
                        SwapPair(CityOrder, (i, j));
                    }
                }

                //Check Dead End
                if (minCost == Cost)
                {
                    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => {
                        TSPCostTextBlock.Text += " DeadEnd X_X";
                    });

                    return;
                }

                CityOrder = bestNeighbour.ToList();
                Cost      = TSPCost(CityOrder);
                if (DisplayEveryStep)
                {
                    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => {
                        DisplayRoute(TSPCanvas);
                        Bindings.Update();
                    });
                }
            }
            await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => {
                DisplayRoute(TSPCanvas);
                TSPCostTextBlock.Text += " Done!";
            });
        }