double VRP::RTR_solve(int heuristics, int intensity, int max_stuck, int max_perturbs,
double dev, int nlist_size, int perturb_type, int accept_type, bool verbose)
{
///
/// Uses the given parameters to generate a
/// VRP solution via record-to-record travel.
/// Assumes that data has already been imported into V and that we have
/// some existing solution.
/// Returns the objective function value of the best solution found
///
// Make sure accept_type is either VRPH_BEST_ACCEPT or VRPH_FIRST_ACCEPT - matters only
// for the downhill phase as we use VRPH_LI_ACCEPT in the diversification phase
if(accept_type!=VRPH_BEST_ACCEPT && accept_type!=VRPH_FIRST_ACCEPT)
report_error("%s: accept_type must be VRPH_BEST_ACCEPT or VRPH_FIRST_ACCEPT\n");
int ctr, n, j, i, R, random, fixed, neighbor_list, objective, tabu;
random=fixed=neighbor_list=0;
if(heuristics & VRPH_RANDOMIZED)
random=VRPH_RANDOMIZED;
if(heuristics & VRPH_FIXED_EDGES)
fixed=VRPH_FIXED_EDGES;
if(heuristics & VRPH_USE_NEIGHBOR_LIST)
neighbor_list=VRPH_USE_NEIGHBOR_LIST;
objective=VRPH_SAVINGS_ONLY;
// default strategy
if(heuristics & VRPH_MINIMIZE_NUM_ROUTES)
objective=VRPH_MINIMIZE_NUM_ROUTES;
if(heuristics & VRPH_TABU)
{
tabu=VRPH_TABU; // We will use a primitive Tabu Search in the uphill phase
// Clear the tabu list
this->tabu_list->empty();
}
else
tabu=0;
n=num_nodes;
// Define the heuristics we will use
OnePointMove OPM;
TwoPointMove TPM;
TwoOpt TO;
OrOpt OR;
ThreeOpt ThreeO;
CrossExchange CE;
ThreePointMove ThreePM;
double start_val;
int *perm;
perm=new int[this->num_nodes];
j=VRPH_ABS(this->next_array[VRPH_DEPOT]);
for(i=0;i<this->num_nodes;i++)
{
perm[i]=j;
if(!routed[j])
report_error("%s: Unrouted node in solution!!\n");
j=VRPH_ABS(this->next_array[j]);
}
if(j!=VRPH_DEPOT)
report_error("%s: VRPH_DEPOT is not last node in solution!!\n");
int rules;
// Set the neighbor list size used in the improvement search
neighbor_list_size=VRPH_MIN(nlist_size, this->num_nodes);
// Set the deviation
deviation=dev;
int num_perturbs=0;
record=this->total_route_length;
this->best_total_route_length=this->total_route_length;
this->export_solution_buff(this->current_sol_buff);
this->export_solution_buff(this->best_sol_buff);
normalize_route_numbers();
ctr=0;
uphill:
// Start an uphill phase using the following "rules":
double beginning_best=this->best_total_route_length;
rules=VRPH_LI_ACCEPT+VRPH_RECORD_TO_RECORD+objective+random+fixed+neighbor_list+tabu;
if(verbose)
printf("Uphill starting at %5.2f\n",this->total_route_length);
for(int k=1;k<intensity;k++)
{
start_val=total_route_length;
if(heuristics & ONE_POINT_MOVE)
{
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
{
#if FIXED_DEBUG
if(fixed && !check_fixed_edges("Before 1PM\n"))
fprintf(stderr,"Error before OPM search(%d)\n",perm[i-1]);
#endif
OPM.search(this,perm[i-1],rules);
#if FIXED_DEBUG
if(fixed && !check_fixed_edges("After 1PM\n"))
{
fprintf(stderr,"Error after OPM search(%d)\n",perm[i-1]);
this->show_route(this->route_num[perm[i-1]]);
}
#endif
}
}
if(heuristics & TWO_POINT_MOVE)
{
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
TPM.search(this,perm[i-1],rules + VRPH_INTER_ROUTE_ONLY);
//check_fixed_edges("After 2PM\n");
}
if(heuristics & THREE_POINT_MOVE)
{
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
ThreePM.search(this,perm[i-1],rules + VRPH_INTER_ROUTE_ONLY);
//check_fixed_edges("After 3PM\n");
}
if(heuristics & TWO_OPT)
{
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
TO.search(this,perm[i-1],rules);
//check_fixed_edges("After TO\n");
}
if(heuristics & OR_OPT)
{
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
OR.search(this,perm[i-1],4,rules);
for(i=1;i<=n;i++)
OR.search(this,perm[i-1],3,rules);
for(i=1;i<=n;i++)
OR.search(this,perm[i-1],2,rules);
//check_fixed_edges("After OR\n");
}
if(heuristics & THREE_OPT)
{
normalize_route_numbers();
R=total_number_of_routes;
for(i=1; i<=R; i++)
ThreeO.route_search(this,i,rules-neighbor_list);
//check_fixed_edges("After 3O\n");
}
if(heuristics & CROSS_EXCHANGE)
{
normalize_route_numbers();
this->find_neighboring_routes();
R=total_number_of_routes;
for(i=1; i<=R-1; i++)
{
for(j=0;j<1;j++)
CE.route_search(this,i, route[i].neighboring_routes[j],rules-neighbor_list);
}
//check_fixed_edges("After CE\n");
}
}
if(total_route_length<record)
record = total_route_length;
if(verbose)
{
printf("Uphill complete\t(%d,%5.2f,%5.2f)\n",count_num_routes(),total_route_length, record);
printf("# of recorded routes: %d[%d]\n",total_number_of_routes,count_num_routes());
}
if(this->best_total_route_length<beginning_best-VRPH_EPSILON)
{
if(verbose)
printf("New best found in uphill!\n");
// We found a new best solution during the uphill phase that might
// now be "forgotten"!! I have seen this happen where it is never recovered
// again, so we just import it and start the downhill phase with this solution...
//this->import_solution_buff(this->best_sol_buff);
}
downhill:
// Now enter a downhill phase
double orig_val=total_route_length;
if(verbose)
printf("Downhill starting at %f (best=%f)\n",orig_val,this->best_total_route_length);
if((heuristics & ONE_POINT_MOVE)|| (heuristics & KITCHEN_SINK) )
{
rules=VRPH_DOWNHILL+objective+random+fixed+neighbor_list+accept_type;
for(;;)
{
// One Point Move
start_val=total_route_length;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
OPM.search(this,perm[i-1],rules );
if(VRPH_ABS(total_route_length-start_val)<VRPH_EPSILON)
break;
}
}
if((heuristics & TWO_POINT_MOVE) || (heuristics & KITCHEN_SINK) )
{
rules=VRPH_DOWNHILL+VRPH_INTER_ROUTE_ONLY+objective+random+fixed+neighbor_list+accept_type;
for(;;)
{
// Two Point Move
start_val=total_route_length;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
TPM.search(this,perm[i-1],rules);
if(VRPH_ABS(total_route_length-start_val)<VRPH_EPSILON)
break;
}
}
if((heuristics & TWO_OPT)|| (heuristics & KITCHEN_SINK) )
{
// Do inter-route first a la Li
rules=VRPH_DOWNHILL+VRPH_INTER_ROUTE_ONLY+objective+random+fixed+neighbor_list+accept_type;
for(;;)
{
start_val=total_route_length;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
TO.search(this,perm[i-1],rules);
if(VRPH_ABS(total_route_length-start_val)<VRPH_EPSILON)
break;
}
// Now do both intra and inter
rules=VRPH_DOWNHILL+objective+random+fixed+neighbor_list+accept_type;
for(;;)
{
start_val=total_route_length;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
TO.search(this,perm[i-1],rules);
if(VRPH_ABS(total_route_length-start_val)<VRPH_EPSILON)
break;
}
}
if((heuristics & THREE_POINT_MOVE) || (heuristics & KITCHEN_SINK) )
{
rules=VRPH_DOWNHILL+VRPH_INTER_ROUTE_ONLY+objective+random+fixed+accept_type+neighbor_list;
for(;;)
{
// Three Point Move
start_val=total_route_length;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
ThreePM.search(this,perm[i-1],rules);
if(VRPH_ABS(total_route_length-start_val)<VRPH_EPSILON)
break;
}
}
if((heuristics & OR_OPT) || (heuristics & KITCHEN_SINK))
{
rules=VRPH_DOWNHILL+ objective +random +fixed + accept_type + neighbor_list;
for(;;)
{
// OrOpt
start_val=total_route_length;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
OR.search(this,perm[i-1],4,rules);
for(i=1;i<=n;i++)
OR.search(this,perm[i-1],3,rules);
for(i=1;i<=n;i++)
OR.search(this,perm[i-1],2,rules);
if(VRPH_ABS(total_route_length-start_val)<VRPH_EPSILON)
break;
}
}
if((heuristics & THREE_OPT) || (heuristics & KITCHEN_SINK) )
{
normalize_route_numbers();
R= total_number_of_routes;
rules=VRPH_DOWNHILL+objective+VRPH_INTRA_ROUTE_ONLY+ random +fixed + accept_type;
for(;;)
{
// 3OPT
start_val=total_route_length;
for(i=1;i<=R;i++)
ThreeO.route_search(this,i,rules);
if(VRPH_ABS(total_route_length-start_val)<VRPH_EPSILON)
break;
}
}
if( (heuristics & CROSS_EXCHANGE) )
{
normalize_route_numbers();
this->find_neighboring_routes();
R=total_number_of_routes;
rules=VRPH_DOWNHILL+objective+VRPH_INTRA_ROUTE_ONLY+ random +fixed + accept_type;
for(i=1; i<=R-1; i++)
{
for(j=0;j<=1;j++)
CE.route_search(this,i, route[i].neighboring_routes[j], rules);
}
}
// Repeat the downhill phase until we find no more improvements
if(total_route_length<orig_val-VRPH_EPSILON)
goto downhill;
if(verbose)
printf("Downhill complete: %5.2f[downhill started at %f] (%5.2f)\n",total_route_length,orig_val,
this->best_total_route_length);
if(total_route_length < record-VRPH_EPSILON)
{
// New record - reset ctr
ctr=1;
record=total_route_length;
}
else
ctr++;
if(ctr<max_stuck)
goto uphill;
if(ctr==max_stuck)
{
if(num_perturbs<max_perturbs)
{
if(verbose)
printf("perturbing\n");
if(perturb_type==VRPH_LI_PERTURB)
perturb();
else
osman_perturb(VRPH_MAX(20,num_nodes/10),.5+lcgrand(20));
// Reset record
this->record=this->total_route_length;
if(tabu)
this->tabu_list->empty();
ctr=1;
num_perturbs++;
goto uphill;
}
}
if(verbose)
{
if(has_service_times==false)
printf("BEST OBJ: %f\n",best_total_route_length);
else
printf("BEST OBJ: %f\n",best_total_route_length-total_service_time);
}
delete [] perm;
// Import the best solution found
this->import_solution_buff(best_sol_buff);
if(has_service_times==false)
return best_total_route_length;
else
return best_total_route_length-total_service_time;
}
double VRP::SA_solve(int heuristics, double start_temp, double cool_ratio,
int iters_per_loop, int num_loops, int nlist_size, bool verbose)
{
///
/// Uses the given parameters to generate a VRP solution using Simulated Annealing.
/// Assumes that data has already been imported into V and that we have
/// some existing solution. Returns the total route length of the best solution found.
///
this->temperature = start_temp;
this->cooling_ratio = cool_ratio;
int ctr, n, j, i, R, rules, random, fixed, neighbor_list, objective;
if(heuristics & VRPH_RANDOMIZED)
random=VRPH_RANDOMIZED;
else
random=0;
if(heuristics & VRPH_FIXED_EDGES)
fixed=VRPH_FIXED_EDGES;
else
fixed=0;
if(heuristics & VRPH_USE_NEIGHBOR_LIST)
neighbor_list=VRPH_USE_NEIGHBOR_LIST;
else
neighbor_list=0;
objective=VRPH_SAVINGS_ONLY;
// default strategy
if(heuristics & VRPH_MINIMIZE_NUM_ROUTES)
objective=VRPH_MINIMIZE_NUM_ROUTES;
n=num_nodes;
// The perm[] array will contain all the nodes in the current solution
int *perm;
perm=new int[this->num_nodes];
j=VRPH_ABS(this->next_array[VRPH_DEPOT]);
for(i=0;i<this->num_nodes;i++)
{
perm[i]=j;
if(!routed[j])
report_error("%s: Unrouted node in solution!!\n");
j=VRPH_ABS(this->next_array[j]);
}
if(j!=VRPH_DEPOT)
report_error("%s: VRPH_DEPOT is not last node in solution!!\n");
// Define the heuristics we may use
OnePointMove OPM;
TwoPointMove TPM;
TwoOpt TO;
OrOpt OR;
ThreeOpt ThreeO;
CrossExchange CE;
ThreePointMove ThreePM;
double start_val;
this->export_solution_buff(this->best_sol_buff);
// We are assuming we have an existing solution
// Set the neighbor list size used in the improvement search
this->neighbor_list_size=VRPH_MIN(nlist_size, num_nodes);
best_total_route_length=this->total_route_length;
normalize_route_numbers();
ctr=0;
// The idea is to perform num_loops loops of num_iters iterations each.
// For each iteration, run through the given heuristic operation at random
// and perform a Simulated Annealing search.
rules=VRPH_USE_NEIGHBOR_LIST+VRPH_FIRST_ACCEPT+VRPH_SIMULATED_ANNEALING+VRPH_SAVINGS_ONLY;
double worst_obj=0;
for(ctr=0;ctr<num_loops;ctr++)
{
if(verbose)
{
printf("\nctr=%d of %d, temp=%f, obj=%f (overall best=%f; worst=%f)\n",ctr,num_loops,
this->temperature,
this->total_route_length,this->best_total_route_length,worst_obj);
fflush(stdout);
}
// Reset worst_obj;
worst_obj=0;
// Cool it...
this->temperature = this->cooling_ratio * this->temperature;
for(int k=0; k < iters_per_loop; k++)
{
start_val=total_route_length;
if(heuristics & THREE_OPT)
{
rules=VRPH_SIMULATED_ANNEALING+VRPH_INTRA_ROUTE_ONLY+random+fixed+objective;
normalize_route_numbers();
R=total_number_of_routes;
for(i=1; i<=R; i++)
{
ThreeO.route_search(this,i,rules);
if(this->total_route_length > worst_obj)
worst_obj=this->total_route_length;
}
}
if(heuristics & ONE_POINT_MOVE)
{
rules=VRPH_SIMULATED_ANNEALING+neighbor_list+random+fixed+objective;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
{
OPM.search(this,perm[i-1],rules);
if(this->total_route_length > worst_obj)
worst_obj=this->total_route_length;
}
}
if(heuristics & TWO_POINT_MOVE)
{
rules=VRPH_SIMULATED_ANNEALING+neighbor_list+random+fixed+objective;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
{
TPM.search(this,perm[i-1],rules);
if(this->total_route_length > worst_obj)
worst_obj=this->total_route_length;
}
}
if(heuristics & TWO_OPT)
{
rules=VRPH_SIMULATED_ANNEALING+neighbor_list+random+fixed+objective;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
{
TO.search(this,perm[i-1],rules);
if(this->total_route_length > worst_obj)
worst_obj=this->total_route_length;
}
}
if(heuristics & THREE_POINT_MOVE)
{
rules=VRPH_SIMULATED_ANNEALING+VRPH_INTER_ROUTE_ONLY+neighbor_list+random+fixed+objective;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
{
ThreePM.search(this,perm[i-1],rules);
if(this->total_route_length > worst_obj)
worst_obj=this->total_route_length;
}
}
if(heuristics & OR_OPT)
{
rules=VRPH_SIMULATED_ANNEALING+neighbor_list+random+fixed+objective;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1;i<=n;i++)
{
OR.search(this,perm[i-1],3,rules);
if(this->total_route_length > worst_obj)
worst_obj=this->total_route_length;
}
for(i=1;i<=n;i++)
{
OR.search(this,perm[i-1],2,rules);
if(this->total_route_length > worst_obj)
worst_obj=this->total_route_length;
}
}
if(heuristics & CROSS_EXCHANGE)
{
normalize_route_numbers();
this->find_neighboring_routes();
R=total_number_of_routes;
rules=VRPH_SIMULATED_ANNEALING+fixed+objective;
if(random)
random_permutation(perm, this->num_nodes);
for(i=1; i<=R-1; i++)
{
for(j=0;j<=1;j++)
{
CE.route_search(this,i, route[i].neighboring_routes[j],rules);
if(this->total_route_length > worst_obj)
worst_obj=this->total_route_length;
}
}
}
}
}
delete [] perm;
// Restore the best sol
this->import_solution_buff(this->best_sol_buff);
// Now return the obj. function value
if(has_service_times==false)
return this->best_total_route_length;
else
return this->best_total_route_length-total_service_time;
}
int main(int argc, char **argv)
{
VRPH_version();
int i, j, k, n, status, num_attempts, *sol_buff, *IP_sol_buff;
char in_file[200];
double lambda, best_heur_sol=VRP_INFINITY;
bool first_sol=false, bootstrap=false;;
VRPSolution *fresh_solution;
OsiSolverInterface *si;
const double *x;
int last_num_cols=0, route_id=0;
time_t start, stop;
int *orderings[MAX_ROUTES];
for(i=0;i<MAX_ROUTES;i++)
orderings[i]=NULL;
// Set timing counters to 0
heur_time=mip_time=0;
// Check arguments
if(argc<5)
{
fprintf(stderr,"Usage: %s -f input_file -n num_runs [-v,-b,-c max_columns -d cols_to_delete]\n",
argv[0]);
fprintf(stderr,"\t Will solve the problem num_solutions times and add the routes\n");
fprintf(stderr,"\t to a set partitioning problem.\n");
fprintf(stderr,"\t Other options:\n");
fprintf(stderr,"\t -v runs in verbose mode\n");
fprintf(stderr,"\t -b will use bootstrapping where we send the set partitioning\n"
"\t solution back to the metaheuristic solver\n");
fprintf(stderr,"\t -c max_columns will allow this many active columns/variables in the IP.\n");
fprintf(stderr,"\t Default value is max_columns=500\n");
fprintf(stderr,"\t -d num_cols_to_delete will delete this many columns once we have too many\n");
fprintf(stderr,"\t in the IP. Default value is num_cols_to_delete=100\n");
exit(-1);
}
// Set defaults
verbose=false;
max_columns=500;
num_cols_to_delete=100;
// Parse command line
for(i=0;i<argc;i++)
{
if(strcmp(argv[i],"-f")==0)
strcpy(in_file,argv[i+1]);
if(strcmp(argv[i],"-n")==0)
num_attempts=atoi(argv[i+1]);
if(strcmp(argv[i],"-v")==0)
verbose=true;
if(strcmp(argv[i],"-b")==0)
bootstrap=true;
if(strcmp(argv[i],"-c")==0)
max_columns=atoi(argv[i+1]);
if(strcmp(argv[i],"-d")==0)
num_cols_to_delete=atoi(argv[i+1]);
}
// This is the # of non-VRPH_DEPOT nodes
n=VRPGetDimension(in_file);
// This will be used to import/export solutions
fresh_solution = new VRPSolution(n);
// Create buffers for importing solutions
sol_buff= new int[n+2];
IP_sol_buff = new int[n+2];
// Declare an OSI interface
si=new OsiGlpkSolverInterface;
si->setIntParam(OsiNameDiscipline,2);
for(i=0;i<n;i++)
{
si->addRow(0,NULL,NULL,1,1);
}
// Declare a VRP of the right size and import the file
VRP V(n);
ClarkeWright CW(n);
VRPRoute route(n);
V.read_TSPLIB_file(in_file);
// Set up a "route warehouse" to store the routes to be added to the IP
V.route_wh=new VRPRouteWarehouse(HASH_TABLE_SIZE);
// Set up a minimization problem
si->setObjSense(1);
// Set to error only output
si->setHintParam(OsiDoReducePrint,true, OsiHintDo);
// Unfortunately GLPK still prints out something regarding the conflict graph
for(i=0;i<num_attempts;i++)
{
if(i==0 || !bootstrap)
{
lambda=.5+1.5*lcgrand(0);
// Start with a clean VRP object
V.reset();
CW.Construct(&V, lambda, false);
if(verbose)
printf("CW solution %d[%5.3f]: %f\n",i,lambda,V.get_total_route_length()-V.get_total_service_time());
}
else
// Use the solution from the IP
V.import_solution_buff(IP_sol_buff);
// Run VRPH's RTR algorithm to improve the solution
start=clock();
V.RTR_solve(ONE_POINT_MOVE | TWO_POINT_MOVE | TWO_OPT | VRPH_USE_NEIGHBOR_LIST,
30, 5, 2, .01, 30, VRPH_LI_PERTURB, VRPH_FIRST_ACCEPT,false);
stop=clock();
heur_time += (stop-start);
if(verbose)
printf("RTR Metaheuristic found solution %5.3f\n",V.get_total_route_length()-V.get_total_service_time());
// The RTR algorithm keeps a "warehouse" of the best solutions discovered during
// the algorithm's search
// Now go through the solutions in the solution warehouse and add the new routes
// discovered to the IP
for(j=0;j<V.solution_wh->num_sols;j++)
{
// Import solution j from the warehouse
V.import_solution_buff(V.solution_wh->sols[j].sol);
if(V.get_total_route_length()-V.get_total_service_time() < best_heur_sol)
best_heur_sol = V.get_total_route_length()-V.get_total_service_time() ;
// Now add the routes from this solution to the IP
for(k=1;k<=V.get_total_number_of_routes();k++)
{
// Clean up the route by running INTRA_ROUTE optimizations only
// using the route_search method of the different local search
// heuristics, accepting improving moves only (VRPH_DOWNHILL)
OnePointMove OPM;
TwoOpt TO;
ThreeOpt ThO;
while(OPM.route_search(&V,k,k,VRPH_DOWNHILL|VRPH_INTRA_ROUTE_ONLY )){}
while(TO.route_search(&V,k,k,VRPH_DOWNHILL|VRPH_INTRA_ROUTE_ONLY )){};
while(ThO.route_search(&V,k,VRPH_DOWNHILL|VRPH_INTRA_ROUTE_ONLY )){};
// Copy route k from the solution to the VRPRoute R
V.update_route(k,&route);
route.create_name();
// Add it to the "route warehouse" - this uses a hash table to keep track
// of duplicate columns
status=V.route_wh->add_route(&route);
if(status!=DUPLICATE_ROUTE)
{
// This route is not currently in the WH and so it cannot be in the
// set partitioning problem
//OSI_add_route(si,&V,&route);
OSI_add_route(si,&V,&route,route_id,orderings);
route_id++;
}
}
// Set the row RHS's if we need to
if(first_sol)
{
first_sol=false;
for(int rownum=0;rownum<n;rownum++)
si->setRowBounds(rownum,1,1);
// Note that changing this to >= would be a set covering problem
// where each customer can be visited by more than one route
}
}
// Now erase all the solutions from the WH
V.solution_wh->liquidate();
if(verbose)
{
printf("Attempt %02d: Solving IP with %d columns\n",i,si->getNumCols());
printf("%d routes in the WH\n",V.route_wh->num_unique_routes);
}
// Solve the current set partitioning problem using the MIP solver
start=clock();
si->branchAndBound();
stop=clock();
mip_time += (stop-start);
double opt=si->getObjValue();
x=si->getColSolution();
last_num_cols=si->getNumCols();
if(verbose)
printf("Optimal solution (%d columns) is %f\n",last_num_cols,opt);
// Now recover the solution from the IP solution
OSI_recover_solution(si, orderings, IP_sol_buff);
if(verbose)
printf("IP solution has obj. function value: %5.2f\n"
"Best heuristic obj. function value: %5.2f\n",
si->getObjValue(),best_heur_sol);
}
if(verbose)
printf(
"\nResults\n"
"--------\n"
"After %d runs\n"
"IP solution has obj. function value: %5.2f\n"
"Best heuristic obj. function value: %5.2f\n",
num_attempts,si->getObjValue(),best_heur_sol);
// print to stderr since GLPK prints "conflict graph" to stdout (a known bug...)
// best_heur_sol best_mip_sol heur_time mip_time
fprintf(stderr,"%5.3f %5.3f %5.3f %5.3f\n", best_heur_sol, si->getObjValue(),
(double)(heur_time)/CLOCKS_PER_SEC, (double)(mip_time)/CLOCKS_PER_SEC);
delete V.route_wh;
delete fresh_solution;
delete [] sol_buff;
delete [] IP_sol_buff;
delete si;
for(i=0;i<MAX_ROUTES;i++)
if(orderings[i])
delete [] orderings[i];
return 0;
}