int CMyProblem::PrintMIPSolution(ostream &out)
{
glp_create_index(lp);
out << "MIP solution" << endl;
out << "Dir;" << ((glp_get_obj_dir(lp)==GLP_MIN) ? "min" : "max") << endl;
out << "f;" << glp_mip_obj_val(lp) << endl;
out << "Status;" << DecodeStatus(glp_mip_status(lp)) << endl;
PrintSolArray(lp,"x",out,true);
PrintSolArray(lp,"y",out,true);
glp_delete_index(lp);
return 0;
}
int CMyProblem::PrintLPSolution(ostream &out)
{
glp_create_index(lp);
out << "LP solution" << endl;
out << "Dir;" << ((glp_get_obj_dir(lp)==GLP_MIN) ? "min" : "max") << endl;
out << "f; " << glp_get_obj_val(lp) << ";/*" << RealResult() << "*/" << endl;
out << "Status;" << DecodeStatus(glp_get_status(lp)) << endl;
PrintSolArray(lp,"x",out);
PrintSolArray(lp,"y",out);
glp_delete_index(lp);
return 0;
}
int main(int argc, char * argv[]) {
int i,j;
time(&initial);
srand(SEED);
/* Default values */
outFile = stdout;
maxAlpha = 2;
maxIter = 100;
maxTime = 30;
randomSeed = SEED;
simpleOutput = 0;
/* Read arguments */
if( argc > 7 )
argc = 7;
switch(argc) {
case 7:
simpleOutput = atoi(argv[6]);
case 6:
if( !(randomSeed = atoi(argv[5])) )
leave(argv[0]);
case 5:
if( !(maxTime = atoi(argv[4])) )
leave(argv[0]);
case 4:
if( !(maxIter = atoi(argv[3])) )
leave(argv[0]);
case 3:
if( !(maxAlpha = atoi(argv[2])) )
leave(argv[0]);
case 2:
if( simpleOutput ) {
if( !(outFile = fopen(argv[1],"a")) )
leave(argv[0]);
break;
}
if( !(outFile = fopen(argv[1],"w")) )
leave(argv[0]);
}
readInput(stdin);
/* Initiate positions */
for( i = 0 ; i < n ; ++i ) {
pOrd[i].ideal = planes[i].ideal;
pOrd[i].pos = i;
}
qsort (pOrd, n, sizeof(struct planeOrder), compIdealT);
for( i = 0 ; i < n ; ++i ) {
planes[pOrd[i].pos].pos = i;
}
/* Create lp instance */
glp_prob * Prob;
Prob = glp_create_prob();
glp_set_prob_name(Prob, "Airplane Landing Problem");
glp_set_obj_name(Prob, "Cost");
/* Create basic constraints */
for( i = 0 ; i < n ; ++i ) {
addBasicRestriction(Prob,i);
}
glp_create_index(Prob);
/* Create separation constraints and order variables (&ij) if necessary */
for( i = 0 ; i < n ; ++i ) {
for( j = i+1 ; j < n ; ++j ) {
if( planes[i].latest >= planes[j].earliest &&
planes[j].latest >= planes[i].earliest ) {
addOrderConstraint(Prob,i,j);
} else if ( planes[i].latest < planes[j].earliest &&
planes[i].latest + planes[i].sep[j] >= planes[j].earliest ) {
addSeparationConstraint(Prob, i, j);
} else if ( planes[j].latest < planes[i].earliest &&
planes[j].latest + planes[j].sep[i] >= planes[i].earliest ) {
addSeparationConstraint(Prob, j, i);
}
}
}
/* Write problem in MPS format so glpsol can (try to) solve it */
glp_write_mps(Prob, GLP_MPS_FILE, NULL,"mpsProblem.txt");
glp_delete_index(Prob);
glp_create_index(Prob);
/* GRASP */
/* Data to handle glp solving, time checking and solution generating */
glp_smcp * param = malloc(sizeof(glp_smcp));
glp_init_smcp(param);
param->msg_lev = GLP_MSG_ERR;
int solution[MAXSIZE], timeAux[MAXSIZE], t;
double currResult = DBL_MAX, bestResult = DBL_MAX;
alpha = 0;
time_t start, curr;
time(&start);
for( t = 0 ; t < maxIter ; ++t ) {
/* Greedy solution generation */
while(createSolution(solution,timeAux,0))
alpha = n;
/* Building the right constraints */
mapSolution(Prob,solution);
/* Solving with glpsol */
param->presolve = GLP_ON;
glp_simplex(Prob,param);
param->presolve = GLP_OFF;
currResult = glp_get_obj_val(Prob);
/* Local search using the first increase */
for( i = 0 ; i < n-1 ; ++i ) {
/* Swap two adjacent planes */
swapConstraint(Prob,i,solution,0);
glp_simplex(Prob,param);
/* Check for improvements */
if( GLP_OPT == glp_get_status(Prob) && glp_get_obj_val(Prob) < currResult ) {
currResult = glp_get_obj_val(Prob);
/* Changing the solution */
int swp;
swp = solution[i];
solution[i] = solution[i+1];
solution[i+1] = swp;
/* Restarting */
i = -1;
} else
swapConstraint(Prob,i,solution,1);
}
/* Checking improvements */
if( bestResult > currResult ) {
bestResult = currResult;
for( i = 0 ; i < n ; ++i )
planes[solution[i]].pos = i;
}
/* Choosing alpha */
alpha = rand()%(maxAlpha+1);
/* Is our time up? */
time(&curr);
if( difftime(curr,start) > maxTime )
break;
}
/* Print Answer */
printResult(Prob, stdout);
if( outFile ) {
printResult(Prob, outFile);
fclose(outFile);
}
return 0;
}
void lpx_delete_index(LPX *lp)
{ /* delete the name index */
glp_delete_index(lp);
return;
}
int glp_read_lp(glp_prob *P, const glp_cpxcp *parm, const char *fname)
{ /* read problem data in CPLEX LP format */
glp_cpxcp _parm;
struct csa _csa, *csa = &_csa;
int ret;
xprintf("Reading problem data from '%s'...\n", fname);
if (parm == NULL)
glp_init_cpxcp(&_parm), parm = &_parm;
/* check control parameters */
check_parm("glp_read_lp", parm);
/* initialize common storage area */
csa->P = P;
csa->parm = parm;
csa->fname = fname;
csa->fp = NULL;
if (setjmp(csa->jump))
{ ret = 1;
goto done;
}
csa->count = 0;
csa->c = '\n';
csa->token = T_EOF;
csa->image[0] = '\0';
csa->imlen = 0;
csa->value = 0.0;
csa->n_max = 100;
csa->ind = xcalloc(1+csa->n_max, sizeof(int));
csa->val = xcalloc(1+csa->n_max, sizeof(double));
csa->flag = xcalloc(1+csa->n_max, sizeof(char));
memset(&csa->flag[1], 0, csa->n_max * sizeof(char));
csa->lb = xcalloc(1+csa->n_max, sizeof(double));
csa->ub = xcalloc(1+csa->n_max, sizeof(double));
#if 1 /* 27/VII-2013 */
csa->lb_warn = csa->ub_warn = 0;
#endif
/* erase problem object */
glp_erase_prob(P);
glp_create_index(P);
/* open input CPLEX LP file */
csa->fp = glp_open(fname, "r");
if (csa->fp == NULL)
{ xprintf("Unable to open '%s' - %s\n", fname, get_err_msg());
ret = 1;
goto done;
}
/* scan very first token */
scan_token(csa);
/* parse definition of the objective function */
if (!(csa->token == T_MINIMIZE || csa->token == T_MAXIMIZE))
error(csa, "'minimize' or 'maximize' keyword missing\n");
parse_objective(csa);
/* parse constraints section */
if (csa->token != T_SUBJECT_TO)
error(csa, "constraints section missing\n");
parse_constraints(csa);
/* parse optional bounds section */
if (csa->token == T_BOUNDS) parse_bounds(csa);
/* parse optional general, integer, and binary sections */
while (csa->token == T_GENERAL ||
csa->token == T_INTEGER ||
csa->token == T_BINARY) parse_integer(csa);
/* check for the keyword 'end' */
if (csa->token == T_END)
scan_token(csa);
else if (csa->token == T_EOF)
warning(csa, "keyword 'end' missing\n");
else
error(csa, "symbol '%s' in wrong position\n", csa->image);
/* nothing must follow the keyword 'end' (except comments) */
if (csa->token != T_EOF)
error(csa, "extra symbol(s) detected beyond 'end'\n");
/* set bounds of variables */
{ int j, type;
double lb, ub;
for (j = 1; j <= P->n; j++)
{ lb = csa->lb[j];
ub = csa->ub[j];
if (lb == +DBL_MAX) lb = 0.0; /* default lb */
if (ub == -DBL_MAX) ub = +DBL_MAX; /* default ub */
if (lb == -DBL_MAX && ub == +DBL_MAX)
type = GLP_FR;
else if (ub == +DBL_MAX)
type = GLP_LO;
else if (lb == -DBL_MAX)
type = GLP_UP;
else if (lb != ub)
type = GLP_DB;
else
type = GLP_FX;
glp_set_col_bnds(csa->P, j, type, lb, ub);
}
}
/* print some statistics */
xprintf("%d row%s, %d column%s, %d non-zero%s\n",
P->m, P->m == 1 ? "" : "s", P->n, P->n == 1 ? "" : "s",
P->nnz, P->nnz == 1 ? "" : "s");
if (glp_get_num_int(P) > 0)
{ int ni = glp_get_num_int(P);
int nb = glp_get_num_bin(P);
if (ni == 1)
{ if (nb == 0)
xprintf("One variable is integer\n");
else
xprintf("One variable is binary\n");
}
else
{ xprintf("%d integer variables, ", ni);
if (nb == 0)
xprintf("none");
else if (nb == 1)
xprintf("one");
else if (nb == ni)
xprintf("all");
else
xprintf("%d", nb);
xprintf(" of which %s binary\n", nb == 1 ? "is" : "are");
}
}
xprintf("%d lines were read\n", csa->count);
/* problem data has been successfully read */
glp_delete_index(P);
glp_sort_matrix(P);
ret = 0;
done: if (csa->fp != NULL) glp_close(csa->fp);
xfree(csa->ind);
xfree(csa->val);
xfree(csa->flag);
xfree(csa->lb);
xfree(csa->ub);
if (ret != 0) glp_erase_prob(P);
return ret;
}
