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!";
});
}
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!";
});
}