//Method that tries to take first request from random route and tries to relocate it to other route ( if allocation is impossible then returning same solution)
private Solution MakeMutation(Solution sol){
_counter++;
Random rnd = new Random();
int random = rnd.Next(sol.RoutesCollection.Count - 1); //find random route
CRoute randomRoute = sol.RoutesCollection.ElementAt(random);
var requestAndSlots = randomRoute.TakenSlotsArrayForRequest.FirstOrDefault(); //TODO: For now its not random just firstOrDefault for better optimization it should be random
while (requestAndSlots.Value == null) //if there is no request alocated find other route with allocated request
{
random = rnd.Next(sol.RoutesCollection.Count - 1);
randomRoute = sol.RoutesCollection.ElementAt(random);
requestAndSlots = randomRoute.TakenSlotsArrayForRequest.FirstOrDefault();
}
CRequest req = CGlobalManager.GlobalRequestList.FirstOrDefault(x => x.Id == requestAndSlots.Key);// we are looking for this request and one more time randomly allocating somewhere
CRoute newRoute = Solution.GetRandomRouteForRequest(req,randomRoute.Index); //Trying to find new route for this request
if (newRoute == null){return sol;} //if the new route is null it means that the slot allocation for other route was impossible
randomRoute.FreeSlots(requestAndSlots); //Free the slots on the previous route
if (!randomRoute.TakenSlotsArrayForRequest.Any()) //If the previous route hasn't any other request then delete it from solution
{
sol.RoutesCollection.Remove(randomRoute);
}
sol.RoutesCollection.Add(newRoute);
sol.PrintSolution(_counter);
return sol;
}
public Solution(Solution source){
this.RoutesCollection = new List<CRoute>();
foreach (var route in source.RoutesCollection)
{
RoutesCollection.Add(new CRoute(route));
}
this._cost = source.GetCost();
}
//Method that will calculate our solution
public Solution CalculateSolution(){
Solution sol = new Solution();
sol.GetRandomSolution(); //creating start solution
sol.PrintSolution(_counter);
Solution bestSol = new Solution(sol); //start solution is automaticaly best solution
Solution _sol = new Solution(sol); //next solution
int costSol, cost_Sol, costBestSol; //cost of current solution, cost of next solution, cost of best solution
costSol = sol.GetCost();
costBestSol = costSol;
while (_startTemperature > _endTemperature) { //Annealing algorithm starts iterate here
_sol = MakeMutation(sol); // we take next random solution
cost_Sol = _sol.GetCost(); // taking the cost of next solution
if (cost_Sol < costBestSol){ //checking if the new solution is better than old one
bestSol = new Solution(_sol);
costBestSol = cost_Sol;
}
#region algorithm calculation ...
double delta = cost_Sol - costSol;
if (delta < 0){
sol = new Solution(_sol);
costSol = cost_Sol;
}
else{
Random rnd = new Random();
double x = (rnd.Next(10000)) / 10000.0; // random number <0, 1)
if (x < Math.Exp(((-delta) / _startTemperature))){
sol = new Solution(_sol);
costSol = cost_Sol;
}
}
#endregion
_startTemperature *= _annealingParameter; // we decrease the start temperature by the annealingParameter
}
return bestSol;
}