public Solution ImproveSolution(Solution initialSolution, List<Customer> selected, List<Route> routes)
{
if (selected == null)
return initialSolution;
var oldDist = initialSolution.TotalDistance();
Solution bestSolution = initialSolution;
foreach (var c in selected)
{
foreach (var r in routes)
{
var transfer = BestInsertionPlaceCzech2001(initialSolution, c, r);
if(transfer.Value < oldDist)
{
bestSolution = transfer.Key;
oldDist = transfer.Value;
}
}
}
return bestSolution;
}
private void Button1Click(object sender, EventArgs e)
{
var reader = new CsvProblemReader();
_problem = reader.Read(@"TestData/c1_2_1_v50_c200.csv");
var sol87Solver = new Solomon87();
var t = ShapleyDivider.Divide(_problem);
_p1 = sol87Solver.Solve(t[0]);
_p2 = sol87Solver.Solve(t[1]);
_p3 = sol87Solver.Solve(t[2]);
_p12 = sol87Solver.Solve(ShapleyDivider.Merge(t[0], t[1]));
_p23 = sol87Solver.Solve(ShapleyDivider.Merge(t[1], t[2]));
_p31 = sol87Solver.Solve(ShapleyDivider.Merge(t[2], t[0]));
_p123 = sol87Solver.Solve(_problem);
textBox1.Text = _p123.PrintToString();
Draw();
}
public static List<double> ComputeGains(ref Solution p1, ref Solution p2, ref Solution p3, ref Solution p12, ref Solution p23, ref Solution p31, ref Solution p123,
int max_iters = 30, Update update = null, VrpSolver solver = null)
{
if (solver == null) solver = DefaultSolver;
/////
for (var i = 0; i < max_iters; ++i)
{
p1 = solver.Solve(p1.Problem, p1);
p2 = solver.Solve(p2.Problem, p2);
p3 = solver.Solve(p3.Problem, p3);
p12 = solver.Solve(p12.Problem, p12);
p23 = solver.Solve(p23.Problem, p23);
p31 = solver.Solve(p31.Problem, p31);
p123 = solver.Solve(p123.Problem, p123);
var v1 = p1.TotalDistance();
var v2 = p2.TotalDistance();
var v3 = p3.TotalDistance();
var v12 = p12.TotalDistance();
var v23 = p23.TotalDistance();
var v31 = p31.TotalDistance();
var v123 = p123.TotalDistance();
var phi1 = 1.0 * 3.0 / v1 + 1.0 / 6.0 * (v12 - v2) + 1.0 / 6.0 * (v31 - v3) + 1.0 / 3.0 * (v123 - v23);
var phi2 = 1.0 * 3.0 / v2 + 1.0 / 6.0 * (v23 - v3) + 1.0 / 6.0 * (v12 - v1) + 1.0 / 3.0 * (v123 - v31);
var phi3 = 1.0 * 3.0 / v3 + 1.0 / 6.0 * (v31 - v1) + 1.0 / 6.0 * (v23 - v2) + 1.0 / 3.0 * (v123 - v12);
p1.Phi = v1 - phi1;
p2.Phi = v2 - phi2;
p3.Phi = v3 - phi3;
update(max_iters, i);
}
return null;
}
public KeyValuePair<Solution, double> BestInsertionPlaceCzech2001(Solution solution, Customer customer, Route route)
{
// Route customerRoute = solution.Routes[customerRouteIndex];
// Customer customer = (Customer)customerRoute.RouteList[cusotomerIndex];
// Route targetRoute = solution.Routes[targetRouteIndex];
//int bestSolution = -1;
double bestCost = solution.TotalDistance();
//solution.Routes[cusotomerIndex] = customerRoute.Copy();
//solution.Routes[cusotomerIndex].RouteList.RemoveAt(cusotomerIndex);
var routeIndex = route.Index();
var newSolution = solution.Copy();
var oldRouteIdx = customer.Route.Index();
var oldRoute = newSolution.Routes[oldRouteIdx].Copy();
oldRoute.RemoveAt(customer.Index());
newSolution.Routes[oldRouteIdx] = oldRoute;
Solution bestSolutionCopy = null;
for (int i = 1; i < route.RouteList.Count; ++i)
{
var newRoute = solution.Routes[routeIndex].Copy();
newRoute.InsertCustomer(customer, i);
newSolution.Routes[routeIndex] = newRoute;
double newCost = newSolution.TotalDistance();
if (newRoute.IsFeasible() && newCost < bestCost)
{
bestSolutionCopy = newSolution.Copy();
bestCost = newCost;
}
}
return new KeyValuePair<Solution, double>(bestSolutionCopy, bestCost);
}
public override Solution Solve(Problem problem, Solution initialSolution)
{
var cNumber = (int) (problem.Customers.Count*CNumCoef);
/* 1. */
var selected = SelectionStage(initialSolution, cNumber);
/* 2. */
var p = .75;
var probablyOrdered = OrderRoutesWithProb(initialSolution, p);
/* 3. */
var newSolution = ImproveSolution(initialSolution, selected, probablyOrdered);
return newSolution;
}
public List<Customer> SelectionStage(Solution initialSolution, int cNumber)
{
//var deletionList = new List<Customer>(cNumber);
var iter = 0;
var neighbourhood = new List<Customer>();
var routes = new List<Route>(initialSolution.Routes);
while(neighbourhood.Count < cNumber){
var customerList = initialSolution.CustomerListCopy();
/* 1.1. */
int routeOneIdx = RandomSampleIndex(0, routes.Count - 1);
/* 1.2. */
int customerIdx = RandomSampleIndex(1, routes[routeOneIdx].RouteList.Count - 2);
Route routeOne = initialSolution.Routes[routeOneIdx];
Customer customer = (Customer)routeOne.RouteList[customerIdx];
/* 1.3. */
neighbourhood = NeighbourhoodIrmSearch(customerList, customer);
/* 1.4. */
foreach (Customer cust in neighbourhood)
customerList.Remove(cust);
/* 1.5. */
if (neighbourhood.Count == 1)
{
//routeOneIdx = RandomSampleIndex(0, routes.Count - 1);
//routeOne = initialSolution.Routes[routeOneIdx];
// implement 1.6.-1.8.
/*
int bestInsertion = BestInsertionPlaceCzech2001(initialSolution, customer.Route.Index(),
customer.Index(),
routeOne.Index());*/
//throw new Exception("WL09 LS: Only one neighbour is found");
}
//if (neighbourhood.Count < cNumber)
// return SelectionStage(initialSolution, cNumber);
if (iter == 30000)
return null;
iter++;
}
return neighbourhood;
}
public List<Route> OrderRoutesWithProb(Solution solution, double prob)
{
var routes = solution.Copy().Routes;
var rnd = new Random();
var dice = rnd.NextDouble();
if(dice > prob)
return new List<Route>(routes);
return routes.OrderBy(r => r.RouteList.Count).ToList();
}
public override Solution Solve(Problem problem, Solution initialSolution = null)
{
var solution = new Solution(problem);
var unroutedCustomers = new List<Customer>(problem.Customers);
int seedId = SelectSeedCustomer(unroutedCustomers, problem.Depot);
Customer seed = unroutedCustomers[seedId];
unroutedCustomers.RemoveAt(seedId);
var partialRoute = new Route(problem, seed);
while (unroutedCustomers.Count > 0)
{
Route newRoute = partialRoute.Copy();
var bestU = new List<int>();
var c1Vals = new List<double>();
foreach (Customer cust in unroutedCustomers)
{
double minC1 = double.MaxValue;
int optimalU = 1;
for (int i = 1; i < newRoute.RouteList.Count - 1; ++i)
{
double c1 = CriterionC1(i, cust, i + 1, newRoute);
if (c1 < minC1)
{
minC1 = c1;
optimalU = i;
}
}
bestU.Add(optimalU);
c1Vals.Add(minC1);
}
int bestCust = 0;
double minC2 = double.MaxValue;
for (int i = 0; i < unroutedCustomers.Count; ++i)
{
double c2 = CriterionC2(unroutedCustomers[i], c1Vals[i], newRoute);
if (c2 < minC2)
{
minC2 = c2;
bestCust = i;
}
}
Customer newCustomer = unroutedCustomers[bestCust];
newRoute.InsertCustomer(newCustomer, bestU[bestCust]);
if (newRoute.IsFeasible())
{
unroutedCustomers.RemoveAt(bestCust);
partialRoute = newRoute;
}
else
{
solution.AddRoute(partialRoute);
seedId = SelectSeedCustomer(unroutedCustomers, problem.Depot);
seed = unroutedCustomers[seedId];
unroutedCustomers.RemoveAt(seedId);
partialRoute = new Route(problem, seed);
}
if (unroutedCustomers.Count == 0)
solution.AddRoute(partialRoute);
}
return solution;
}
public Solution Copy()
{
var sol = new Solution(Problem);
foreach (Route route in Routes)
if(route.RouteList.Count > 2)
sol.AddRoute(route.Copy());
return sol;
}
