// Set components[i] to the representative of the
// component that contains the vertex i.
void getComponents (IloCplex &cplex,
const IloArray <IloBoolVarArray>& solution,
vector <int>& components) {
// The size of the graph.
int n = solution.getSize();
// Each vertex is a component itself.
for (int i = 0; i < n; i++)
components[i] = i;
// For each 1 in the incidence matrix,
// join the components of these vertex.
for (int i = 0; i < n; i++)
for (int j = i + 1; j < n; j++)
if (cplex.getValue (solution[i][j]) == 1)
join (components, i, j);
}
// Finds the total path if there's no irregularity or an sub-path that
// contains I and not I - n (Infeasible for family (5))
void getPath (const IloCplex& cplex,
const IloArray <IloBoolVarArray>& solution,
vector <int>& P,
vector<int>& VP,
int src,
const vector< Client > &precedences,
bool reverse) {
// The depot always belongs to P
P.push_back(src);
// Mark the vertex alread visited on the path
vector< bool > visited ( solution.getSize(), false );
visited [src] = true;
// Each iteration finds the next vertex on the path
while ( P.size() < (size_t) solution.getSize() ) {
// Finds the next vertex on the path (after src on the route)
int v;
for (v = ((reverse && (P.size() == 1)) ? 1 : 0);
v < solution [src].getSize();
v++) {
if ((cplex.getValue (solution [src][v])) &&
(visited [v] == false) )
break;
}
// There must be such a vertex v (This solution is TSP feasible)
//assert (v < solution.getSize());
// Testing infeasibility (Searching in the precedence rules)
for (size_t i = 0; i < precedences.size(); i++) {
// If v is a location in this pair (rule)
if (precedences[i].delivery == v ||
precedences[i].pickup == v) {
// Adding v to the path and starting over with src == v;
P.push_back(v); src = v; visited [v] = true;
// Checking infeasibility
if (!reverse) {
// If v is a delivery vertex and its pickup wasn't visited yet
if ((precedences[i].delivery == v) &&
(visited [ precedences[i].pickup ] == false)) {
getCutComplement (visited, VP);
return;
}
}
else {
// If v is a pickup vertex and its delivery wasn't visited yet
if ((precedences[i].pickup == v) &&
(visited [ precedences[i].delivery ] == false)) {
getCutComplement (visited, VP);
return;
}
}
// v is feasible
break;
}
}
// Test other vertex at the while
}
}
ILOSTLBEGIN
int main(int argc, char** argv)
{
IloEnv env ;
try
{
IloModel model(env) ;
IloCplex cplex(env) ;
// Get data
// Import data from file
try
{
//IloInt i, j ;
const char* filename ;
if (argc > 1)
filename = argv[1] ;
else
filename = "data/tsp.dat" ;
ifstream f(filename, ios::in) ;
if (!f)
{
cerr << "No such file: " << filename << endl ;
throw(1) ;
}
// Create data matrix
IloArray<IloNumArray> costmatrix (env) ;
f >> costmatrix ;
IloInt n = costmatrix.getSize() ;
// Define variables and "fill" them so as not to get seg faults
IloArray<IloIntVarArray> x (env, n) ;
for (i=0 ; i<n ; i++)
{
x[i] = IloIntVarArray (env, n) ;
for(IloInt j=0 ; j<n ; j++)
{
x[i][j] = IloIntVar (env) ;
}
}
IloIntVarArray u (env, n) ;
for(i=0 ; i<n ; i++)
{
u[i] = IloIntVar (env) ;
}
// Define constraints
IloExpr constr_i (env) ;
IloExpr constr_j (env) ;
IloExpr constr_u (env) ;
// Vertical constraint
// Create a full vector with a hole to express the vertical constraint as a scalar product
IloIntArray basevector (env, n) ;
basevector[0] = 0 ;
for (int i=1 ; i<n ; i++)
{
basevector[i] = 1 ;
}
constr_i = IloScalProd(basevector, x[0]) ;
model.add( constr_i == 1) ;
for (i=1 ; i < n ; i++)
{
basevector[i-1] = 1 ;
basevector[i] = 0 ;
constr_i = IloScalProd(basevector, x[i]) ;
model.add(constr_i == 1) ;
for (j=0 ; j < n ; j++)
{
if (i != j)
{
constr_j += x[j][i] ;
constr_u = u[i] - u[j] + n*x[i][j] ;
model.add(constr_u == 1) ;
}
}
model.add(constr_j == 1) ;
}
// Define objective
IloExpr obj (env) ;
for (i=1 ; i < n ; i++)
{
for (j=0 ; j < n ; j++)
{
if (i != j)
{
obj += costmatrix[i][j] * x[i][j] ;
}
}
}
model.add( IloMinimize(env, obj) ) ;
// Extract model
cplex.extract(model);
// Export model
// Set parameters
// Solve
if ( !cplex.solve() )
{
env.error() << "Failed to optimize problem" << endl;
cplex.out() << "Solution status " << cplex.getStatus() << endl ;
cplex.out() << "Model" << cplex.getModel() << endl ;
throw(-1);
}
cplex.out() << "Solution status " << cplex.getStatus() << endl;
cplex.out() << "Objective value " << cplex.getObjValue() << endl;
// Print solution details
}
catch (IloException& e)
{
cerr << "Concert exception caught: " << e << endl;
}
}
catch (...)
{
cerr << "Unknown exception caught" << endl ;
}
// freeing memory
env.end();
return 0;
} // END main
