private static void ExecuteTabuSearch()
{
TSPEnvironment tspEnvironment = new TSPEnvironment();
tspEnvironment.distances = //Distance matrix, 5x5, used to represent distances
new int[, ] {
{ 0, 1, 3, 4, 5 },
{ 1, 0, 1, 4, 8 },
{ 3, 1, 0, 5, 1 },
{ 4, 4, 5, 0, 2 },
{ 5, 8, 1, 2, 0 }
};
//Between cities. 0,1 represents distance between cities 0 and 1, and so on.
int[] currSolution = new int[] { 0, 1, 2, 3, 4, 0 }; //initial solution
//city numbers start from 0
// the first and last cities' positions do not change
int numberOfIterations = 100;
int tabuLength = 5;
TspList tabuList = new TspList(tabuLength);
int[] bestSol = new int[currSolution.Length]; //this is the best Solution So Far
Array.Copy(currSolution, 0, bestSol, 0, bestSol.Length);
int bestCost = tspEnvironment.GetObjectiveFunctionValue(bestSol);
for (int i = 0; i < numberOfIterations; i++)
{ // perform iterations here
currSolution = TabuSearch.GetBestNeighbour(tabuList, tspEnvironment, currSolution);
//printSolution(currSolution);
int currCost = tspEnvironment.GetObjectiveFunctionValue(currSolution);
//System.out.println("Current best cost = " + tspEnvironment.getObjectiveFunctionValue(currSolution));
if (currCost < bestCost)
{
Array.Copy(currSolution, 0, bestSol, 0, bestSol.Length);
bestCost = currCost;
}
}
Console.WriteLine("Search done! \nBest Solution cost found = " + bestCost + "\nBest Solution :");
PrintSolution(bestSol);
}
public static int[] GetBestNeighbour(TspList tabuList,
TSPEnvironment tspEnviromnet,
int[] initSolution)
{
int[] bestSol = new int[initSolution.Length]; //this is the best Solution So Far
Array.Copy(initSolution, 0, bestSol, 0, bestSol.Length);
int bestCost = tspEnviromnet.GetObjectiveFunctionValue(initSolution);
int city1 = 0;
int city2 = 0;
bool firstNeighbor = true;
for (int i = 1; i < bestSol.Length - 1; i++)
{
for (int j = 2; j < bestSol.Length - 1; j++)
{
if (i == j)
{
continue;
}
int[] newBestSol = new int[bestSol.Length]; //this is the best Solution So Far
Array.Copy(bestSol, 0, newBestSol, 0, newBestSol.Length);
newBestSol = SwapOperator(i, j, initSolution); //Try swapping cities i and j
// , maybe we get a bettersolution
int newBestCost = tspEnviromnet.GetObjectiveFunctionValue(newBestSol);
if ((newBestCost > bestCost || firstNeighbor) && tabuList.tabuList[i, j] == 0)
{ //if better move found, store it
firstNeighbor = false;
city1 = i;
city2 = j;
Array.Copy(newBestSol, 0, bestSol, 0, newBestSol.Length);
bestCost = newBestCost;
}
}
}
if (city1 != 0)
{
tabuList.decrementTabu();
tabuList.tabuMove(city1, city2);
}
return(bestSol);
}
