glpapi17.c

著名的大规模线性规划求解器源码GLPK.C语言版本,可以修剪.内有详细帮助文档.

         }
      }
      /*--------------------------------------------------------------*/
      /* read problem data from the input file */
      if (csa->in_file == NULL)
      {  xprintf("No input problem file specified; try %s --help\n",
            argv[0]);
         ret = EXIT_FAILURE;
         goto done;
      }
      if (csa->format == FMT_MPS_DECK)
      {  ret = glp_read_mps(csa->prob, GLP_MPS_DECK, NULL,
            csa->in_file);
         if (ret != 0)
err1:    {  xprintf("MPS file processing error\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      else if (csa->format == FMT_MPS_FILE)
      {  ret = glp_read_mps(csa->prob, GLP_MPS_FILE, NULL,
            csa->in_file);
         if (ret != 0) goto err1;
      }
      else if (csa->format == FMT_CPLEX_LP)
      {  ret = glp_read_lp(csa->prob, NULL, csa->in_file);
         if (ret != 0)
         {  xprintf("CPLEX LP file processing error\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      else if (csa->format == FMT_MATHPROG)
      {  int k;
         /* allocate the translator workspace */
         csa->tran = glp_mpl_alloc_wksp();
         /* read model section and optional data section */
         if (glp_mpl_read_model(csa->tran, csa->in_file, csa->ndf > 0))
err2:    {  xprintf("MathProg model processing error\n");
            ret = EXIT_FAILURE;
            goto done;
         }
         /* read optional data section(s), if necessary */
         for (k = 1; k <= csa->ndf; k++)
         {  if (glp_mpl_read_data(csa->tran, csa->in_data[k]))
               goto err2;
         }
         /* generate the model */
         if (glp_mpl_generate(csa->tran, csa->out_dpy)) goto err2;
         /* build the problem instance from the model */
         glp_mpl_build_prob(csa->tran, csa->prob);
      }
      else if (csa->format == FMT_MIN_COST)
      {  csa->graph = glp_create_graph(sizeof(v_data), sizeof(a_data));
         ret = glp_read_mincost(csa->graph, offsetof(v_data, rhs),
            offsetof(a_data, low), offsetof(a_data, cap),
            offsetof(a_data, cost), csa->in_file);
         if (ret != 0)
         {  xprintf("DIMACS file processing error\n");
            ret = EXIT_FAILURE;
            goto done;
         }
         glp_mincost_lp(csa->prob, csa->graph, GLP_ON,
            offsetof(v_data, rhs), offsetof(a_data, low),
            offsetof(a_data, cap), offsetof(a_data, cost));
         glp_set_prob_name(csa->prob, csa->in_file);
      }
      else if (csa->format == FMT_MAX_FLOW)
      {  int s, t;
         csa->graph = glp_create_graph(sizeof(v_data), sizeof(a_data));
         ret = glp_read_maxflow(csa->graph, &s, &t,
            offsetof(a_data, cap), csa->in_file);
         if (ret != 0)
         {  xprintf("DIMACS file processing error\n");
            ret = EXIT_FAILURE;
            goto done;
         }
         glp_maxflow_lp(csa->prob, csa->graph, GLP_ON, s, t,
            offsetof(a_data, cap));
         glp_set_prob_name(csa->prob, csa->in_file);
      }
      else
         xassert(csa != csa);
      /*--------------------------------------------------------------*/
      /* change problem name, if required */
      if (csa->new_name != NULL)
         glp_set_prob_name(csa->prob, csa->new_name);
      /* change optimization direction, if required */
      if (csa->dir != 0)
         glp_set_obj_dir(csa->prob, csa->dir);
      /* order rows and columns of the constraint matrix */
      lpx_order_matrix(csa->prob);
      /*--------------------------------------------------------------*/
      /* write problem data in fixed MPS format, if required */
      if (csa->out_mps != NULL)
      {  ret = glp_write_mps(csa->prob, GLP_MPS_DECK, NULL,
            csa->out_mps);
         if (ret != 0)
         {  xprintf("Unable to write problem in fixed MPS format\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      /* write problem data in free MPS format, if required */
      if (csa->out_freemps != NULL)
      {  ret = glp_write_mps(csa->prob, GLP_MPS_FILE, NULL,
            csa->out_freemps);
         if (ret != 0)
         {  xprintf("Unable to write problem in free MPS format\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      /* write problem data in CPLEX LP format, if required */
      if (csa->out_cpxlp != NULL)
      {  ret = glp_write_lp(csa->prob, NULL, csa->out_cpxlp);
         if (ret != 0)
         {  xprintf("Unable to write problem in CPLEX LP format\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      /* write problem data in OPB format, if required */
      if (csa->out_pb != NULL)
      {  ret = lpx_write_pb(csa->prob, csa->out_pb, 0, 0);
         if (ret != 0)
         {  xprintf("Unable to write problem in OPB format\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      /* write problem data in normalized OPB format, if required */
      if (csa->out_npb != NULL)
      {  ret = lpx_write_pb(csa->prob, csa->out_npb, 1, 1);
         if (ret != 0)
         {  xprintf(
               "Unable to write problem in normalized OPB format\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      /*--------------------------------------------------------------*/
      /* if only problem data check is required, skip computations */
      if (csa->check)
      {  ret = EXIT_SUCCESS;
         goto done;
      }
      /*--------------------------------------------------------------*/
      /* determine the solution type */
      if (!csa->nomip &&
          glp_get_num_int(csa->prob) + glp_get_num_bin(csa->prob) > 0)
      {  if (csa->solution == SOL_INTERIOR)
         {  xprintf("Interior-point method is not able to solve MIP pro"
               "blem; use --simplex\n");
            ret = EXIT_FAILURE;
            goto done;
         }
         csa->solution = SOL_INTEGER;
      }
      /*--------------------------------------------------------------*/
      /* if solution is provided, read it and skip computations */
      if (csa->in_res != NULL)
      {  if (csa->solution == SOL_BASIC)
            ret = glp_read_sol(csa->prob, csa->in_res);
         else if (csa->solution == SOL_INTERIOR)
            ret = glp_read_ipt(csa->prob, csa->in_res);
         else if (csa->solution == SOL_INTEGER)
            ret = glp_read_mip(csa->prob, csa->in_res);
         else
            xassert(csa != csa);
         if (ret != 0)
         {  xprintf("Unable to read problem solution\n");
            ret = EXIT_FAILURE;
            goto done;
         }
         goto skip;
      }
      /*--------------------------------------------------------------*/
      /* scale the problem data, if required */
      if (csa->scale)
      {  if (csa->solution == SOL_BASIC && !csa->smcp.presolve ||
             csa->solution == SOL_INTERIOR ||
             csa->solution == SOL_INTEGER && !csa->iocp.presolve)
            glp_scale_prob(csa->prob, GLP_SF_AUTO);
      }
      /* construct starting LP basis */
      if (csa->solution == SOL_BASIC && !csa->smcp.presolve ||
          csa->solution == SOL_INTEGER && !csa->iocp.presolve)
      {  if (csa->crash == USE_STD_BASIS)
            glp_std_basis(csa->prob);
         else if (csa->crash == USE_ADV_BASIS)
            glp_adv_basis(csa->prob, 0);
         else if (csa->crash == USE_CPX_BASIS)
            glp_cpx_basis(csa->prob);
         else
            xassert(csa != csa);
      }
      /*--------------------------------------------------------------*/
      /* solve the problem */
      start = xtime();
      if (csa->solution == SOL_BASIC)
      {  if (!csa->exact)
         {  glp_set_bfcp(csa->prob, &csa->bfcp);
            glp_simplex(csa->prob, &csa->smcp);
            if (csa->xcheck)
            {  if (csa->smcp.presolve &&
                   glp_get_status(csa->prob) != GLP_OPT)
                  xprintf("If you need to check final basis for non-opt"
                     "imal solution, use --nopresol\n");
               else
                  glp_exact(csa->prob, &csa->smcp);
            }
            if (csa->out_sol != NULL || csa->out_res != NULL)
            {  if (csa->smcp.presolve &&
                   glp_get_status(csa->prob) != GLP_OPT)
               xprintf("If you need actual output for non-optimal solut"
                  "ion, use --nopresol\n");
            }
         }
         else
            glp_exact(csa->prob, &csa->smcp);
      }
      else if (csa->solution == SOL_INTERIOR)
         glp_interior(csa->prob, NULL);
      else if (csa->solution == SOL_INTEGER)
      {  if (!csa->iocp.presolve)
         {  glp_set_bfcp(csa->prob, &csa->bfcp);
            glp_simplex(csa->prob, &csa->smcp);
         }
         glp_intopt(csa->prob, &csa->iocp);
      }
      else
         xassert(csa != csa);
      /*--------------------------------------------------------------*/
      /* display statistics */
      xprintf("Time used:   %.1f secs\n", xdifftime(xtime(), start));
      {  xlong_t tpeak;
         char buf[50];
         lib_mem_usage(NULL, NULL, NULL, &tpeak);
         xprintf("Memory used: %.1f Mb (%s bytes)\n",
            xltod(tpeak) / 1048576.0, xltoa(tpeak, buf));
      }
      /*--------------------------------------------------------------*/
skip: /* postsolve the model, if necessary */
      if (csa->tran != NULL)
      {  if (csa->solution == SOL_BASIC)
            ret = glp_mpl_postsolve(csa->tran, csa->prob, GLP_SOL);
         else if (csa->solution == SOL_INTERIOR)
            ret = glp_mpl_postsolve(csa->tran, csa->prob, GLP_IPT);
         else if (csa->solution == SOL_INTEGER)
            ret = glp_mpl_postsolve(csa->tran, csa->prob, GLP_MIP);
         else
            xassert(csa != csa);
         if (ret != 0)
         {  xprintf("Model postsolving error\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      /*--------------------------------------------------------------*/
      /* write problem solution in printable format, if required */
      if (csa->out_sol != NULL)
      {  if (csa->solution == SOL_BASIC)
            ret = lpx_print_sol(csa->prob, csa->out_sol);
         else if (csa->solution == SOL_INTERIOR)
            ret = lpx_print_ips(csa->prob, csa->out_sol);
         else if (csa->solution == SOL_INTEGER)
            ret = lpx_print_mip(csa->prob, csa->out_sol);
         else
            xassert(csa != csa);
         if (ret != 0)
         {  xprintf("Unable to write problem solution\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      /* write problem solution in printable format, if required */
      if (csa->out_res != NULL)
      {  if (csa->solution == SOL_BASIC)
            ret = glp_write_sol(csa->prob, csa->out_res);
         else if (csa->solution == SOL_INTERIOR)
            ret = glp_write_ipt(csa->prob, csa->out_res);
         else if (csa->solution == SOL_INTEGER)
            ret = glp_write_mip(csa->prob, csa->out_res);
         else
            xassert(csa != csa);
         if (ret != 0)
         {  xprintf("Unable to write problem solution\n");
            ret = EXIT_FAILURE;
            goto done;
         }
      }
      /* write sensitivity bounds information, if required */
      if (csa->out_bnds != NULL)
      {  if (csa->solution == SOL_BASIC)
         {  ret = lpx_print_sens_bnds(csa->prob, csa->out_bnds);
            if (ret != 0)
            {  xprintf("Unable to write sensitivity bounds information "
                  "\n");
               ret = EXIT_FAILURE;
               goto done;
            }
         }
         else
            xprintf("Cannot write sensitivity bounds information for in"
               "terior-point or MIP solution\n");
      }
      /*--------------------------------------------------------------*/
      /* all seems to be ok */
      ret = EXIT_SUCCESS;
      /*--------------------------------------------------------------*/
done: /* delete the LP/MIP problem object */
      if (csa->prob != NULL)
         glp_delete_prob(csa->prob);
      /* free the translator workspace, if necessary */
      if (csa->tran != NULL)
         glp_mpl_free_wksp(csa->tran);
      /* delete the network problem object, if necessary */
      if (csa->graph != NULL)
         glp_delete_graph(csa->graph);
      xassert(gmp_pool_count() == 0);
      gmp_free_mem();
      /* close log file, if necessary */
      if (csa->log_file != NULL) lib_close_log();
      /* check that no memory blocks are still allocated */
      {  int count;
         xlong_t total;
         lib_mem_usage(&count, NULL, &total, NULL);
         if (count != 0)
            xerror("Error: %d memory block(s) were lost\n", count);
         xassert(count == 0);
         xassert(total.lo == 0 && total.hi == 0);
      }
      /* free the library environment */
      lib_free_env();
      /* return to the control program */
      return ret;
}

/* eof */