static bool HasTourElimination(Cplex cplex, Data data, IIntVar[][] x)
{
double[][] sol_x = new double[data.n][];
for (int i = 0; i < data.n; i++)
{
sol_x[i] = cplex.GetValues(x[i]);
}
//int shortestLenght = ShortestCicleInSelectedPaths(sol_x);
int[] tour = FindSubTour(sol_x);
if (tour.Length < data.n)
{
ILinearNumExpr sumx = cplex.LinearNumExpr();
for (int i = 0; i < tour.Length; i++)
{
for (int j = i + 1; j < tour.Length; j++)
{
sumx.AddTerm(1, x[tour[i]][tour[j]]);
}
}
cplex.AddLazyConstraint(cplex.AddLe(cplex.Diff(sumx, (tour.Length + 1)), 0));
return(true);
}
else
{
return(false);
}
}
static void Main()
{
try
{
string resultFilename = "./ResultFiles/MTSP_MTZ.csv";
string filename = "./DataFiles/Data.dat";
Data data = new Data(filename);
double timeFactor = 0;
double distanceFactor = 1;
double step = 0.1;
int routeCounter = 0;
File.WriteAllText(resultFilename, "");
do
{
using (Cplex cplex = new Cplex())
{
#region [Decision Variables]
IIntVar[][] x = new IIntVar[data.n][];
IIntVar Q = cplex.IntVar(1, 250, "Q");
for (int i = 0; i < data.n; i++)
{
x[i] = cplex.BoolVarArray(data.n);
cplex.Add(x[i]);
}
#endregion
#region [Objective Function]
INumExpr obj = cplex.NumExpr();
for (int i = 0; i < data.n; i++)
{
for (int j = 0; j < data.n; j++)
{
if (i != j)
{
obj = cplex.Sum(obj,
cplex.Prod(
(
(timeFactor * data.timeNormalized[i][j]) +
(distanceFactor * data.distanceNormalized[i][j])
), x[i][j]));
}
}
}
cplex.AddMinimize(obj);
#endregion
#region [Restrictions]
for (int j = 0; j < data.n; j++)
{
ILinearNumExpr sumj = cplex.LinearNumExpr();
for (int i = 0; i < data.n; i++)
{
if (i != j)
{
sumj.AddTerm(1, x[i][j]);
}
}
cplex.AddEq(sumj, 1);
}
for (int i = 0; i < data.n; i++)
{
ILinearNumExpr sumi = cplex.LinearNumExpr();
for (int j = 0; j < data.n; j++)
{
if (i != j)
{
sumi.AddTerm(1, x[i][j]);
}
}
cplex.AddEq(sumi, 1);
}
#endregion
cplex.SetParam(Cplex.DoubleParam.WorkMem, 4000.0);
cplex.SetParam(Cplex.Param.MIP.Strategy.File, 2);
cplex.SetParam(Cplex.DoubleParam.EpGap, 0.1);
cplex.SetParam(Cplex.BooleanParam.MemoryEmphasis, true);
cplex.SetParam(Cplex.IntParam.VarSel, 4);
SOLVE:
Stopwatch stopWatch = new Stopwatch();
stopWatch.Start();
if (cplex.Solve())
{
stopWatch.Stop();
double[][] sol_x = new double[data.n][];
for (int i = 0; i < data.n; i++)
{
sol_x[i] = cplex.GetValues(x[i]);
}
int[] tour = FindSubTour(sol_x);
if (tour.Length < data.n)
{
ILinearNumExpr sumx = cplex.LinearNumExpr();
for (int i = 0; i < tour.Length; i++)
{
for (int j = 0; j < tour.Length; j++)
{
sumx.AddTerm(1, x[tour[i]][tour[j]]);
}
}
cplex.AddLazyConstraint(cplex.AddLe(cplex.Diff(sumx, tour.Length), -1));
goto SOLVE;
}
double timeTotal = 0;
double distanceTotal = 0;
for (int i = 0; i < data.n; i++)
{
for (int j = 0; j < data.n; j++)
{
timeTotal += data.time[i][j] * sol_x[i][j];
distanceTotal += data.distance[i][j] * sol_x[i][j];
}
}
StreamWriter file = new StreamWriter(resultFilename, true);
file.WriteLine($"{timeFactor},{distanceFactor},{stopWatch.Elapsed.TotalSeconds},{cplex.ObjValue},{timeTotal},{distanceTotal}");
file.Close();
StreamWriter fileRouteResult = new StreamWriter($"./ResultFiles/Route-{routeCounter}.txt");
for (int i = 0; i < data.n; i++)
{
for (int j = 0; j < data.n; j++)
{
if (sol_x[i][j] == 1)
{
fileRouteResult.WriteLine($"From city {i} to city {j}");
}
}
}
fileRouteResult.Close();
}
cplex.End();
}
timeFactor += step;
distanceFactor -= step;
routeCounter++;
} while (timeFactor <= 1);
}
catch (ILOG.Concert.Exception ex)
{
StreamWriter errorfile = new StreamWriter("./ErrorLog.txt");
errorfile.WriteLine("Exception Kind: ILOG.Concert.Exception (Concert Error)");
errorfile.WriteLine("Message: " + ex.Message);
errorfile.WriteLine("StackTrace: " + ex.StackTrace);
errorfile.Close();
}
catch (InputDataReader.InputDataReaderException ex)
{
StreamWriter errorfile = new StreamWriter("./ErrorLog.txt");
errorfile.WriteLine("Exception Kind: InputDataReader.InputDataReaderException (Data Error)");
errorfile.WriteLine("Message: " + ex.Message);
errorfile.WriteLine("StackTrace: " + ex.StackTrace);
errorfile.Close();
}
catch (System.IO.IOException ex)
{
StreamWriter errorfile = new StreamWriter("./ErrorLog.txt");
errorfile.WriteLine("Exception Kind: System.IO.IOException (IO Error)");
errorfile.WriteLine("Message: " + ex.Message);
errorfile.WriteLine("StackTrace: " + ex.StackTrace);
errorfile.Close();
}
}
