diff -r d59bea55db9b -r c445c931472f src/glpdmx.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/glpdmx.c	Mon Dec 06 13:09:21 2010 +0100
@@ -0,0 +1,1468 @@
+/* glpdmx.c (reading/writing data in DIMACS format) */
+
+/***********************************************************************
+*  This code is part of GLPK (GNU Linear Programming Kit).
+*
+*  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+*  2009, 2010 Andrew Makhorin, Department for Applied Informatics,
+*  Moscow Aviation Institute, Moscow, Russia. All rights reserved.
+*  E-mail: <mao@gnu.org>.
+*
+*  GLPK is free software: you can redistribute it and/or modify it
+*  under the terms of the GNU General Public License as published by
+*  the Free Software Foundation, either version 3 of the License, or
+*  (at your option) any later version.
+*
+*  GLPK is distributed in the hope that it will be useful, but WITHOUT
+*  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+*  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+*  License for more details.
+*
+*  You should have received a copy of the GNU General Public License
+*  along with GLPK. If not, see <http://www.gnu.org/licenses/>.
+***********************************************************************/
+
+#define _GLPSTD_STDIO
+#include "glpapi.h"
+
+struct csa
+{     /* common storage area */
+      jmp_buf jump;
+      /* label for go to in case of error */
+      const char *fname;
+      /* name of input text file */
+      XFILE *fp;
+      /* stream assigned to input text file */
+      int count;
+      /* line count */
+      int c;
+      /* current character */
+      char field[255+1];
+      /* data field */
+      int empty;
+      /* warning 'empty line ignored' was printed */
+      int nonint;
+      /* warning 'non-integer data detected' was printed */
+};
+
+static void error(struct csa *csa, const char *fmt, ...)
+{     /* print error message and terminate processing */
+      va_list arg;
+      xprintf("%s:%d: error: ", csa->fname, csa->count);
+      va_start(arg, fmt);
+      xvprintf(fmt, arg);
+      va_end(arg);
+      xprintf("\n");
+      longjmp(csa->jump, 1);
+      /* no return */
+}
+
+static void warning(struct csa *csa, const char *fmt, ...)
+{     /* print warning message and continue processing */
+      va_list arg;
+      xprintf("%s:%d: warning: ", csa->fname, csa->count);
+      va_start(arg, fmt);
+      xvprintf(fmt, arg);
+      va_end(arg);
+      xprintf("\n");
+      return;
+}
+
+static void read_char(struct csa *csa)
+{     /* read character from input text file */
+      int c;
+      if (csa->c == '\n') csa->count++;
+      c = xfgetc(csa->fp);
+      if (c < 0)
+      {  if (xferror(csa->fp))
+            error(csa, "read error - %s", xerrmsg());
+         else if (csa->c == '\n')
+            error(csa, "unexpected end of file");
+         else
+         {  warning(csa, "missing final end of line");
+            c = '\n';
+         }
+      }
+      else if (c == '\n')
+         ;
+      else if (isspace(c))
+         c = ' ';
+      else if (iscntrl(c))
+         error(csa, "invalid control character 0x%02X", c);
+      csa->c = c;
+      return;
+}
+
+static void read_designator(struct csa *csa)
+{     /* read one-character line designator */
+      xassert(csa->c == '\n');
+      read_char(csa);
+      for (;;)
+      {  /* skip preceding white-space characters */
+         while (csa->c == ' ')
+            read_char(csa);
+         if (csa->c == '\n')
+         {  /* ignore empty line */
+            if (!csa->empty)
+            {  warning(csa, "empty line ignored");
+               csa->empty = 1;
+            }
+            read_char(csa);
+         }
+         else if (csa->c == 'c')
+         {  /* skip comment line */
+            while (csa->c != '\n')
+               read_char(csa);
+            read_char(csa);
+         }
+         else
+         {  /* hmm... looks like a line designator */
+            csa->field[0] = (char)csa->c, csa->field[1] = '\0';
+            /* check that it is followed by a white-space character */
+            read_char(csa);
+            if (!(csa->c == ' ' || csa->c == '\n'))
+               error(csa, "line designator missing or invalid");
+            break;
+         }
+      }
+      return;
+}
+
+static void read_field(struct csa *csa)
+{     /* read data field */
+      int len = 0;
+      /* skip preceding white-space characters */
+      while (csa->c == ' ')
+         read_char(csa);
+      /* scan data field */
+      if (csa->c == '\n')
+         error(csa, "unexpected end of line");
+      while (!(csa->c == ' ' || csa->c == '\n'))
+      {  if (len == sizeof(csa->field)-1)
+            error(csa, "data field `%.15s...' too long", csa->field);
+         csa->field[len++] = (char)csa->c;
+         read_char(csa);
+      }
+      csa->field[len] = '\0';
+      return;
+}
+
+static void end_of_line(struct csa *csa)
+{     /* skip white-space characters until end of line */
+      while (csa->c == ' ')
+         read_char(csa);
+      if (csa->c != '\n')
+         error(csa, "too many data fields specified");
+      return;
+}
+
+static void check_int(struct csa *csa, double num)
+{     /* print a warning if non-integer data are detected */
+      if (!csa->nonint && num != floor(num))
+      {  warning(csa, "non-integer data detected");
+         csa->nonint = 1;
+      }
+      return;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_read_mincost - read min-cost flow problem data in DIMACS format
+*
+*  SYNOPSIS
+*
+*  int glp_read_mincost(glp_graph *G, int v_rhs, int a_low, int a_cap,
+*     int a_cost, const char *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_read_mincost reads minimum cost flow problem data in
+*  DIMACS format from a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_read_mincost(glp_graph *G, int v_rhs, int a_low, int a_cap,
+      int a_cost, const char *fname)
+{     struct csa _csa, *csa = &_csa;
+      glp_vertex *v;
+      glp_arc *a;
+      int i, j, k, nv, na, ret = 0;
+      double rhs, low, cap, cost;
+      char *flag = NULL;
+      if (v_rhs >= 0 && v_rhs > G->v_size - (int)sizeof(double))
+         xerror("glp_read_mincost: v_rhs = %d; invalid offset\n",
+            v_rhs);
+      if (a_low >= 0 && a_low > G->a_size - (int)sizeof(double))
+         xerror("glp_read_mincost: a_low = %d; invalid offset\n",
+            a_low);
+      if (a_cap >= 0 && a_cap > G->a_size - (int)sizeof(double))
+         xerror("glp_read_mincost: a_cap = %d; invalid offset\n",
+            a_cap);
+      if (a_cost >= 0 && a_cost > G->a_size - (int)sizeof(double))
+         xerror("glp_read_mincost: a_cost = %d; invalid offset\n",
+            a_cost);
+      glp_erase_graph(G, G->v_size, G->a_size);
+      if (setjmp(csa->jump))
+      {  ret = 1;
+         goto done;
+      }
+      csa->fname = fname;
+      csa->fp = NULL;
+      csa->count = 0;
+      csa->c = '\n';
+      csa->field[0] = '\0';
+      csa->empty = csa->nonint = 0;
+      xprintf("Reading min-cost flow problem data from `%s'...\n",
+         fname);
+      csa->fp = xfopen(fname, "r");
+      if (csa->fp == NULL)
+      {  xprintf("Unable to open `%s' - %s\n", fname, xerrmsg());
+         longjmp(csa->jump, 1);
+      }
+      /* read problem line */
+      read_designator(csa);
+      if (strcmp(csa->field, "p") != 0)
+         error(csa, "problem line missing or invalid");
+      read_field(csa);
+      if (strcmp(csa->field, "min") != 0)
+         error(csa, "wrong problem designator; `min' expected");
+      read_field(csa);
+      if (!(str2int(csa->field, &nv) == 0 && nv >= 0))
+         error(csa, "number of nodes missing or invalid");
+      read_field(csa);
+      if (!(str2int(csa->field, &na) == 0 && na >= 0))
+         error(csa, "number of arcs missing or invalid");
+      xprintf("Flow network has %d node%s and %d arc%s\n",
+         nv, nv == 1 ? "" : "s", na, na == 1 ? "" : "s");
+      if (nv > 0) glp_add_vertices(G, nv);
+      end_of_line(csa);
+      /* read node descriptor lines */
+      flag = xcalloc(1+nv, sizeof(char));
+      memset(&flag[1], 0, nv * sizeof(char));
+      if (v_rhs >= 0)
+      {  rhs = 0.0;
+         for (i = 1; i <= nv; i++)
+         {  v = G->v[i];
+            memcpy((char *)v->data + v_rhs, &rhs, sizeof(double));
+         }
+      }
+      for (;;)
+      {  read_designator(csa);
+         if (strcmp(csa->field, "n") != 0) break;
+         read_field(csa);
+         if (str2int(csa->field, &i) != 0)
+            error(csa, "node number missing or invalid");
+         if (!(1 <= i && i <= nv))
+            error(csa, "node number %d out of range", i);
+         if (flag[i])
+            error(csa, "duplicate descriptor of node %d", i);
+         read_field(csa);
+         if (str2num(csa->field, &rhs) != 0)
+            error(csa, "node supply/demand missing or invalid");
+         check_int(csa, rhs);
+         if (v_rhs >= 0)
+         {  v = G->v[i];
+            memcpy((char *)v->data + v_rhs, &rhs, sizeof(double));
+         }
+         flag[i] = 1;
+         end_of_line(csa);
+      }
+      xfree(flag), flag = NULL;
+      /* read arc descriptor lines */
+      for (k = 1; k <= na; k++)
+      {  if (k > 1) read_designator(csa);
+         if (strcmp(csa->field, "a") != 0)
+            error(csa, "wrong line designator; `a' expected");
+         read_field(csa);
+         if (str2int(csa->field, &i) != 0)
+            error(csa, "starting node number missing or invalid");
+         if (!(1 <= i && i <= nv))
+            error(csa, "starting node number %d out of range", i);
+         read_field(csa);
+         if (str2int(csa->field, &j) != 0)
+            error(csa, "ending node number missing or invalid");
+         if (!(1 <= j && j <= nv))
+            error(csa, "ending node number %d out of range", j);
+         read_field(csa);
+         if (!(str2num(csa->field, &low) == 0 && low >= 0.0))
+            error(csa, "lower bound of arc flow missing or invalid");
+         check_int(csa, low);
+         read_field(csa);
+         if (!(str2num(csa->field, &cap) == 0 && cap >= low))
+            error(csa, "upper bound of arc flow missing or invalid");
+         check_int(csa, cap);
+         read_field(csa);
+         if (str2num(csa->field, &cost) != 0)
+            error(csa, "per-unit cost of arc flow missing or invalid");
+         check_int(csa, cost);
+         a = glp_add_arc(G, i, j);
+         if (a_low >= 0)
+            memcpy((char *)a->data + a_low, &low, sizeof(double));
+         if (a_cap >= 0)
+            memcpy((char *)a->data + a_cap, &cap, sizeof(double));
+         if (a_cost >= 0)
+            memcpy((char *)a->data + a_cost, &cost, sizeof(double));
+         end_of_line(csa);
+      }
+      xprintf("%d lines were read\n", csa->count);
+done: if (ret) glp_erase_graph(G, G->v_size, G->a_size);
+      if (csa->fp != NULL) xfclose(csa->fp);
+      if (flag != NULL) xfree(flag);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_write_mincost - write min-cost flow problem data in DIMACS format
+*
+*  SYNOPSIS
+*
+*  int glp_write_mincost(glp_graph *G, int v_rhs, int a_low, int a_cap,
+*     int a_cost, const char *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_write_mincost writes minimum cost flow problem data
+*  in DIMACS format to a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_write_mincost(glp_graph *G, int v_rhs, int a_low, int a_cap,
+      int a_cost, const char *fname)
+{     XFILE *fp;
+      glp_vertex *v;
+      glp_arc *a;
+      int i, count = 0, ret;
+      double rhs, low, cap, cost;
+      if (v_rhs >= 0 && v_rhs > G->v_size - (int)sizeof(double))
+         xerror("glp_write_mincost: v_rhs = %d; invalid offset\n",
+            v_rhs);
+      if (a_low >= 0 && a_low > G->a_size - (int)sizeof(double))
+         xerror("glp_write_mincost: a_low = %d; invalid offset\n",
+            a_low);
+      if (a_cap >= 0 && a_cap > G->a_size - (int)sizeof(double))
+         xerror("glp_write_mincost: a_cap = %d; invalid offset\n",
+            a_cap);
+      if (a_cost >= 0 && a_cost > G->a_size - (int)sizeof(double))
+         xerror("glp_write_mincost: a_cost = %d; invalid offset\n",
+            a_cost);
+      xprintf("Writing min-cost flow problem data to `%s'...\n",
+         fname);
+      fp = xfopen(fname, "w");
+      if (fp == NULL)
+      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xfprintf(fp, "c %s\n",
+         G->name == NULL ? "unknown" : G->name), count++;
+      xfprintf(fp, "p min %d %d\n", G->nv, G->na), count++;
+      if (v_rhs >= 0)
+      {  for (i = 1; i <= G->nv; i++)
+         {  v = G->v[i];
+            memcpy(&rhs, (char *)v->data + v_rhs, sizeof(double));
+            if (rhs != 0.0)
+               xfprintf(fp, "n %d %.*g\n", i, DBL_DIG, rhs), count++;
+         }
+      }
+      for (i = 1; i <= G->nv; i++)
+      {  v = G->v[i];
+         for (a = v->out; a != NULL; a = a->t_next)
+         {  if (a_low >= 0)
+               memcpy(&low, (char *)a->data + a_low, sizeof(double));
+            else
+               low = 0.0;
+            if (a_cap >= 0)
+               memcpy(&cap, (char *)a->data + a_cap, sizeof(double));
+            else
+               cap = 1.0;
+            if (a_cost >= 0)
+               memcpy(&cost, (char *)a->data + a_cost, sizeof(double));
+            else
+               cost = 0.0;
+            xfprintf(fp, "a %d %d %.*g %.*g %.*g\n",
+               a->tail->i, a->head->i, DBL_DIG, low, DBL_DIG, cap,
+               DBL_DIG, cost), count++;
+         }
+      }
+      xfprintf(fp, "c eof\n"), count++;
+      xfflush(fp);
+      if (xferror(fp))
+      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xprintf("%d lines were written\n", count);
+      ret = 0;
+done: if (fp != NULL) xfclose(fp);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_read_maxflow - read maximum flow problem data in DIMACS format
+*
+*  SYNOPSIS
+*
+*  int glp_read_maxflow(glp_graph *G, int *s, int *t, int a_cap,
+*     const char *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_read_maxflow reads maximum flow problem data in
+*  DIMACS format from a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_read_maxflow(glp_graph *G, int *_s, int *_t, int a_cap,
+      const char *fname)
+{     struct csa _csa, *csa = &_csa;
+      glp_arc *a;
+      int i, j, k, s, t, nv, na, ret = 0;
+      double cap;
+      if (a_cap >= 0 && a_cap > G->a_size - (int)sizeof(double))
+         xerror("glp_read_maxflow: a_cap = %d; invalid offset\n",
+            a_cap);
+      glp_erase_graph(G, G->v_size, G->a_size);
+      if (setjmp(csa->jump))
+      {  ret = 1;
+         goto done;
+      }
+      csa->fname = fname;
+      csa->fp = NULL;
+      csa->count = 0;
+      csa->c = '\n';
+      csa->field[0] = '\0';
+      csa->empty = csa->nonint = 0;
+      xprintf("Reading maximum flow problem data from `%s'...\n",
+         fname);
+      csa->fp = xfopen(fname, "r");
+      if (csa->fp == NULL)
+      {  xprintf("Unable to open `%s' - %s\n", fname, xerrmsg());
+         longjmp(csa->jump, 1);
+      }
+      /* read problem line */
+      read_designator(csa);
+      if (strcmp(csa->field, "p") != 0)
+         error(csa, "problem line missing or invalid");
+      read_field(csa);
+      if (strcmp(csa->field, "max") != 0)
+         error(csa, "wrong problem designator; `max' expected");
+      read_field(csa);
+      if (!(str2int(csa->field, &nv) == 0 && nv >= 2))
+         error(csa, "number of nodes missing or invalid");
+      read_field(csa);
+      if (!(str2int(csa->field, &na) == 0 && na >= 0))
+         error(csa, "number of arcs missing or invalid");
+      xprintf("Flow network has %d node%s and %d arc%s\n",
+         nv, nv == 1 ? "" : "s", na, na == 1 ? "" : "s");
+      if (nv > 0) glp_add_vertices(G, nv);
+      end_of_line(csa);
+      /* read node descriptor lines */
+      s = t = 0;
+      for (;;)
+      {  read_designator(csa);
+         if (strcmp(csa->field, "n") != 0) break;
+         read_field(csa);
+         if (str2int(csa->field, &i) != 0)
+            error(csa, "node number missing or invalid");
+         if (!(1 <= i && i <= nv))
+            error(csa, "node number %d out of range", i);
+         read_field(csa);
+         if (strcmp(csa->field, "s") == 0)
+         {  if (s > 0)
+               error(csa, "only one source node allowed");
+            s = i;
+         }
+         else if (strcmp(csa->field, "t") == 0)
+         {  if (t > 0)
+               error(csa, "only one sink node allowed");
+            t = i;
+         }
+         else
+            error(csa, "wrong node designator; `s' or `t' expected");
+         if (s > 0 && s == t)
+            error(csa, "source and sink nodes must be distinct");
+         end_of_line(csa);
+      }
+      if (s == 0)
+         error(csa, "source node descriptor missing\n");
+      if (t == 0)
+         error(csa, "sink node descriptor missing\n");
+      if (_s != NULL) *_s = s;
+      if (_t != NULL) *_t = t;
+      /* read arc descriptor lines */
+      for (k = 1; k <= na; k++)
+      {  if (k > 1) read_designator(csa);
+         if (strcmp(csa->field, "a") != 0)
+            error(csa, "wrong line designator; `a' expected");
+         read_field(csa);
+         if (str2int(csa->field, &i) != 0)
+            error(csa, "starting node number missing or invalid");
+         if (!(1 <= i && i <= nv))
+            error(csa, "starting node number %d out of range", i);
+         read_field(csa);
+         if (str2int(csa->field, &j) != 0)
+            error(csa, "ending node number missing or invalid");
+         if (!(1 <= j && j <= nv))
+            error(csa, "ending node number %d out of range", j);
+         read_field(csa);
+         if (!(str2num(csa->field, &cap) == 0 && cap >= 0.0))
+            error(csa, "arc capacity missing or invalid");
+         check_int(csa, cap);
+         a = glp_add_arc(G, i, j);
+         if (a_cap >= 0)
+            memcpy((char *)a->data + a_cap, &cap, sizeof(double));
+         end_of_line(csa);
+      }
+      xprintf("%d lines were read\n", csa->count);
+done: if (ret) glp_erase_graph(G, G->v_size, G->a_size);
+      if (csa->fp != NULL) xfclose(csa->fp);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_write_maxflow - write maximum flow problem data in DIMACS format
+*
+*  SYNOPSIS
+*
+*  int glp_write_maxflow(glp_graph *G, int s, int t, int a_cap,
+*     const char *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_write_maxflow writes maximum flow problem data in
+*  DIMACS format to a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_write_maxflow(glp_graph *G, int s, int t, int a_cap,
+      const char *fname)
+{     XFILE *fp;
+      glp_vertex *v;
+      glp_arc *a;
+      int i, count = 0, ret;
+      double cap;
+      if (!(1 <= s && s <= G->nv))
+         xerror("glp_write_maxflow: s = %d; source node number out of r"
+            "ange\n", s);
+      if (!(1 <= t && t <= G->nv))
+         xerror("glp_write_maxflow: t = %d: sink node number out of ran"
+            "ge\n", t);
+      if (a_cap >= 0 && a_cap > G->a_size - (int)sizeof(double))
+         xerror("glp_write_mincost: a_cap = %d; invalid offset\n",
+            a_cap);
+      xprintf("Writing maximum flow problem data to `%s'...\n",
+         fname);
+      fp = xfopen(fname, "w");
+      if (fp == NULL)
+      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xfprintf(fp, "c %s\n",
+         G->name == NULL ? "unknown" : G->name), count++;
+      xfprintf(fp, "p max %d %d\n", G->nv, G->na), count++;
+      xfprintf(fp, "n %d s\n", s), count++;
+      xfprintf(fp, "n %d t\n", t), count++;
+      for (i = 1; i <= G->nv; i++)
+      {  v = G->v[i];
+         for (a = v->out; a != NULL; a = a->t_next)
+         {  if (a_cap >= 0)
+               memcpy(&cap, (char *)a->data + a_cap, sizeof(double));
+            else
+               cap = 1.0;
+            xfprintf(fp, "a %d %d %.*g\n",
+               a->tail->i, a->head->i, DBL_DIG, cap), count++;
+         }
+      }
+      xfprintf(fp, "c eof\n"), count++;
+      xfflush(fp);
+      if (xferror(fp))
+      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xprintf("%d lines were written\n", count);
+      ret = 0;
+done: if (fp != NULL) xfclose(fp);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_read_asnprob - read assignment problem data in DIMACS format
+*
+*  SYNOPSIS
+*
+*  int glp_read_asnprob(glp_graph *G, int v_set, int a_cost,
+*     const char *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_read_asnprob reads assignment problem data in DIMACS
+*  format from a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_read_asnprob(glp_graph *G, int v_set, int a_cost, const char
+      *fname)
+{     struct csa _csa, *csa = &_csa;
+      glp_vertex *v;
+      glp_arc *a;
+      int nv, na, n1, i, j, k, ret = 0;
+      double cost;
+      char *flag = NULL;
+      if (v_set >= 0 && v_set > G->v_size - (int)sizeof(int))
+         xerror("glp_read_asnprob: v_set = %d; invalid offset\n",
+            v_set);
+      if (a_cost >= 0 && a_cost > G->a_size - (int)sizeof(double))
+         xerror("glp_read_asnprob: a_cost = %d; invalid offset\n",
+            a_cost);
+      glp_erase_graph(G, G->v_size, G->a_size);
+      if (setjmp(csa->jump))
+      {  ret = 1;
+         goto done;
+      }
+      csa->fname = fname;
+      csa->fp = NULL;
+      csa->count = 0;
+      csa->c = '\n';
+      csa->field[0] = '\0';
+      csa->empty = csa->nonint = 0;
+      xprintf("Reading assignment problem data from `%s'...\n", fname);
+      csa->fp = xfopen(fname, "r");
+      if (csa->fp == NULL)
+      {  xprintf("Unable to open `%s' - %s\n", fname, xerrmsg());
+         longjmp(csa->jump, 1);
+      }
+      /* read problem line */
+      read_designator(csa);
+      if (strcmp(csa->field, "p") != 0)
+         error(csa, "problem line missing or invalid");
+      read_field(csa);
+      if (strcmp(csa->field, "asn") != 0)
+         error(csa, "wrong problem designator; `asn' expected");
+      read_field(csa);
+      if (!(str2int(csa->field, &nv) == 0 && nv >= 0))
+         error(csa, "number of nodes missing or invalid");
+      read_field(csa);
+      if (!(str2int(csa->field, &na) == 0 && na >= 0))
+         error(csa, "number of arcs missing or invalid");
+      if (nv > 0) glp_add_vertices(G, nv);
+      end_of_line(csa);
+      /* read node descriptor lines */
+      flag = xcalloc(1+nv, sizeof(char));
+      memset(&flag[1], 0, nv * sizeof(char));
+      n1 = 0;
+      for (;;)
+      {  read_designator(csa);
+         if (strcmp(csa->field, "n") != 0) break;
+         read_field(csa);
+         if (str2int(csa->field, &i) != 0)
+            error(csa, "node number missing or invalid");
+         if (!(1 <= i && i <= nv))
+            error(csa, "node number %d out of range", i);
+         if (flag[i])
+            error(csa, "duplicate descriptor of node %d", i);
+         flag[i] = 1, n1++;
+         end_of_line(csa);
+      }
+      xprintf(
+         "Assignment problem has %d + %d = %d node%s and %d arc%s\n",
+         n1, nv - n1, nv, nv == 1 ? "" : "s", na, na == 1 ? "" : "s");
+      if (v_set >= 0)
+      {  for (i = 1; i <= nv; i++)
+         {  v = G->v[i];
+            k = (flag[i] ? 0 : 1);
+            memcpy((char *)v->data + v_set, &k, sizeof(int));
+         }
+      }
+      /* read arc descriptor lines */
+      for (k = 1; k <= na; k++)
+      {  if (k > 1) read_designator(csa);
+         if (strcmp(csa->field, "a") != 0)
+            error(csa, "wrong line designator; `a' expected");
+         read_field(csa);
+         if (str2int(csa->field, &i) != 0)
+            error(csa, "starting node number missing or invalid");
+         if (!(1 <= i && i <= nv))
+            error(csa, "starting node number %d out of range", i);
+         if (!flag[i])
+            error(csa, "node %d cannot be a starting node", i);
+         read_field(csa);
+         if (str2int(csa->field, &j) != 0)
+            error(csa, "ending node number missing or invalid");
+         if (!(1 <= j && j <= nv))
+            error(csa, "ending node number %d out of range", j);
+         if (flag[j])
+            error(csa, "node %d cannot be an ending node", j);
+         read_field(csa);
+         if (str2num(csa->field, &cost) != 0)
+            error(csa, "arc cost missing or invalid");
+         check_int(csa, cost);
+         a = glp_add_arc(G, i, j);
+         if (a_cost >= 0)
+            memcpy((char *)a->data + a_cost, &cost, sizeof(double));
+         end_of_line(csa);
+      }
+      xprintf("%d lines were read\n", csa->count);
+done: if (ret) glp_erase_graph(G, G->v_size, G->a_size);
+      if (csa->fp != NULL) xfclose(csa->fp);
+      if (flag != NULL) xfree(flag);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_write_asnprob - write assignment problem data in DIMACS format
+*
+*  SYNOPSIS
+*
+*  int glp_write_asnprob(glp_graph *G, int v_set, int a_cost,
+*     const char *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_write_asnprob writes assignment problem data in
+*  DIMACS format to a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_write_asnprob(glp_graph *G, int v_set, int a_cost, const char
+      *fname)
+{     XFILE *fp;
+      glp_vertex *v;
+      glp_arc *a;
+      int i, k, count = 0, ret;
+      double cost;
+      if (v_set >= 0 && v_set > G->v_size - (int)sizeof(int))
+         xerror("glp_write_asnprob: v_set = %d; invalid offset\n",
+            v_set);
+      if (a_cost >= 0 && a_cost > G->a_size - (int)sizeof(double))
+         xerror("glp_write_asnprob: a_cost = %d; invalid offset\n",
+            a_cost);
+      xprintf("Writing assignment problem data to `%s'...\n", fname);
+      fp = xfopen(fname, "w");
+      if (fp == NULL)
+      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xfprintf(fp, "c %s\n",
+         G->name == NULL ? "unknown" : G->name), count++;
+      xfprintf(fp, "p asn %d %d\n", G->nv, G->na), count++;
+      for (i = 1; i <= G->nv; i++)
+      {  v = G->v[i];
+         if (v_set >= 0)
+            memcpy(&k, (char *)v->data + v_set, sizeof(int));
+         else
+            k = (v->out != NULL ? 0 : 1);
+         if (k == 0)
+            xfprintf(fp, "n %d\n", i), count++;
+      }
+      for (i = 1; i <= G->nv; i++)
+      {  v = G->v[i];
+         for (a = v->out; a != NULL; a = a->t_next)
+         {  if (a_cost >= 0)
+               memcpy(&cost, (char *)a->data + a_cost, sizeof(double));
+            else
+               cost = 1.0;
+            xfprintf(fp, "a %d %d %.*g\n",
+               a->tail->i, a->head->i, DBL_DIG, cost), count++;
+         }
+      }
+      xfprintf(fp, "c eof\n"), count++;
+      xfflush(fp);
+      if (xferror(fp))
+      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xprintf("%d lines were written\n", count);
+      ret = 0;
+done: if (fp != NULL) xfclose(fp);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_read_ccdata - read graph in DIMACS clique/coloring format
+*
+*  SYNOPSIS
+*
+*  int glp_read_ccdata(glp_graph *G, int v_wgt, const char *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_read_ccdata reads an (undirected) graph in DIMACS
+*  clique/coloring format from a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_read_ccdata(glp_graph *G, int v_wgt, const char *fname)
+{     struct csa _csa, *csa = &_csa;
+      glp_vertex *v;
+      int i, j, k, nv, ne, ret = 0;
+      double w;
+      char *flag = NULL;
+      if (v_wgt >= 0 && v_wgt > G->v_size - (int)sizeof(double))
+         xerror("glp_read_ccdata: v_wgt = %d; invalid offset\n",
+            v_wgt);
+      glp_erase_graph(G, G->v_size, G->a_size);
+      if (setjmp(csa->jump))
+      {  ret = 1;
+         goto done;
+      }
+      csa->fname = fname;
+      csa->fp = NULL;
+      csa->count = 0;
+      csa->c = '\n';
+      csa->field[0] = '\0';
+      csa->empty = csa->nonint = 0;
+      xprintf("Reading graph from `%s'...\n", fname);
+      csa->fp = xfopen(fname, "r");
+      if (csa->fp == NULL)
+      {  xprintf("Unable to open `%s' - %s\n", fname, xerrmsg());
+         longjmp(csa->jump, 1);
+      }
+      /* read problem line */
+      read_designator(csa);
+      if (strcmp(csa->field, "p") != 0)
+         error(csa, "problem line missing or invalid");
+      read_field(csa);
+      if (strcmp(csa->field, "edge") != 0)
+         error(csa, "wrong problem designator; `edge' expected");
+      read_field(csa);
+      if (!(str2int(csa->field, &nv) == 0 && nv >= 0))
+         error(csa, "number of vertices missing or invalid");
+      read_field(csa);
+      if (!(str2int(csa->field, &ne) == 0 && ne >= 0))
+         error(csa, "number of edges missing or invalid");
+      xprintf("Graph has %d vert%s and %d edge%s\n",
+         nv, nv == 1 ? "ex" : "ices", ne, ne == 1 ? "" : "s");
+      if (nv > 0) glp_add_vertices(G, nv);
+      end_of_line(csa);
+      /* read node descriptor lines */
+      flag = xcalloc(1+nv, sizeof(char));
+      memset(&flag[1], 0, nv * sizeof(char));
+      if (v_wgt >= 0)
+      {  w = 1.0;
+         for (i = 1; i <= nv; i++)
+         {  v = G->v[i];
+            memcpy((char *)v->data + v_wgt, &w, sizeof(double));
+         }
+      }
+      for (;;)
+      {  read_designator(csa);
+         if (strcmp(csa->field, "n") != 0) break;
+         read_field(csa);
+         if (str2int(csa->field, &i) != 0)
+            error(csa, "vertex number missing or invalid");
+         if (!(1 <= i && i <= nv))
+            error(csa, "vertex number %d out of range", i);
+         if (flag[i])
+            error(csa, "duplicate descriptor of vertex %d", i);
+         read_field(csa);
+         if (str2num(csa->field, &w) != 0)
+            error(csa, "vertex weight missing or invalid");
+         check_int(csa, w);
+         if (v_wgt >= 0)
+         {  v = G->v[i];
+            memcpy((char *)v->data + v_wgt, &w, sizeof(double));
+         }
+         flag[i] = 1;
+         end_of_line(csa);
+      }
+      xfree(flag), flag = NULL;
+      /* read edge descriptor lines */
+      for (k = 1; k <= ne; k++)
+      {  if (k > 1) read_designator(csa);
+         if (strcmp(csa->field, "e") != 0)
+            error(csa, "wrong line designator; `e' expected");
+         read_field(csa);
+         if (str2int(csa->field, &i) != 0)
+            error(csa, "first vertex number missing or invalid");
+         if (!(1 <= i && i <= nv))
+            error(csa, "first vertex number %d out of range", i);
+         read_field(csa);
+         if (str2int(csa->field, &j) != 0)
+            error(csa, "second vertex number missing or invalid");
+         if (!(1 <= j && j <= nv))
+            error(csa, "second vertex number %d out of range", j);
+         glp_add_arc(G, i, j);
+         end_of_line(csa);
+      }
+      xprintf("%d lines were read\n", csa->count);
+done: if (ret) glp_erase_graph(G, G->v_size, G->a_size);
+      if (csa->fp != NULL) xfclose(csa->fp);
+      if (flag != NULL) xfree(flag);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_write_ccdata - write graph in DIMACS clique/coloring format
+*
+*  SYNOPSIS
+*
+*  int glp_write_ccdata(glp_graph *G, int v_wgt, const char *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_write_ccdata writes the specified graph in DIMACS
+*  clique/coloring format to a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_write_ccdata(glp_graph *G, int v_wgt, const char *fname)
+{     XFILE *fp;
+      glp_vertex *v;
+      glp_arc *e;
+      int i, count = 0, ret;
+      double w;
+      if (v_wgt >= 0 && v_wgt > G->v_size - (int)sizeof(double))
+         xerror("glp_write_ccdata: v_wgt = %d; invalid offset\n",
+            v_wgt);
+      xprintf("Writing graph to `%s'\n", fname);
+      fp = xfopen(fname, "w");
+      if (fp == NULL)
+      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xfprintf(fp, "c %s\n",
+         G->name == NULL ? "unknown" : G->name), count++;
+      xfprintf(fp, "p edge %d %d\n", G->nv, G->na), count++;
+      if (v_wgt >= 0)
+      {  for (i = 1; i <= G->nv; i++)
+         {  v = G->v[i];
+            memcpy(&w, (char *)v->data + v_wgt, sizeof(double));
+            if (w != 1.0)
+               xfprintf(fp, "n %d %.*g\n", i, DBL_DIG, w), count++;
+         }
+      }
+      for (i = 1; i <= G->nv; i++)
+      {  v = G->v[i];
+         for (e = v->out; e != NULL; e = e->t_next)
+            xfprintf(fp, "e %d %d\n", e->tail->i, e->head->i), count++;
+      }
+      xfprintf(fp, "c eof\n"), count++;
+      xfflush(fp);
+      if (xferror(fp))
+      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xprintf("%d lines were written\n", count);
+      ret = 0;
+done: if (fp != NULL) xfclose(fp);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_read_prob - read problem data in GLPK format
+*
+*  SYNOPSIS
+*
+*  int glp_read_prob(glp_prob *P, int flags, const char *fname);
+*
+*  The routine glp_read_prob reads problem data in GLPK LP/MIP format
+*  from a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_read_prob(glp_prob *P, int flags, const char *fname)
+{     struct csa _csa, *csa = &_csa;
+      int mip, m, n, nnz, ne, i, j, k, type, kind, ret, *ln = NULL,
+         *ia = NULL, *ja = NULL;
+      double lb, ub, temp, *ar = NULL;
+      char *rf = NULL, *cf = NULL;
+      if (P == NULL || P->magic != GLP_PROB_MAGIC)
+         xerror("glp_read_prob: P = %p; invalid problem object\n",
+            P);
+      if (flags != 0)
+         xerror("glp_read_prob: flags = %d; invalid parameter\n",
+            flags);
+      if (fname == NULL)
+         xerror("glp_read_prob: fname = %d; invalid parameter\n",
+            fname);
+      glp_erase_prob(P);
+      if (setjmp(csa->jump))
+      {  ret = 1;
+         goto done;
+      }
+      csa->fname = fname;
+      csa->fp = NULL;
+      csa->count = 0;
+      csa->c = '\n';
+      csa->field[0] = '\0';
+      csa->empty = csa->nonint = 0;
+      xprintf("Reading problem data from `%s'...\n", fname);
+      csa->fp = xfopen(fname, "r");
+      if (csa->fp == NULL)
+      {  xprintf("Unable to open `%s' - %s\n", fname, xerrmsg());
+         longjmp(csa->jump, 1);
+      }
+      /* read problem line */
+      read_designator(csa);
+      if (strcmp(csa->field, "p") != 0)
+         error(csa, "problem line missing or invalid");
+      read_field(csa);
+      if (strcmp(csa->field, "lp") == 0)
+         mip = 0;
+      else if (strcmp(csa->field, "mip") == 0)
+         mip = 1;
+      else
+         error(csa, "wrong problem designator; `lp' or `mip' expected\n"
+            );
+      read_field(csa);
+      if (strcmp(csa->field, "min") == 0)
+         glp_set_obj_dir(P, GLP_MIN);
+      else if (strcmp(csa->field, "max") == 0)
+         glp_set_obj_dir(P, GLP_MAX);
+      else
+         error(csa, "objective sense missing or invalid");
+      read_field(csa);
+      if (!(str2int(csa->field, &m) == 0 && m >= 0))
+         error(csa, "number of rows missing or invalid");
+      read_field(csa);
+      if (!(str2int(csa->field, &n) == 0 && n >= 0))
+         error(csa, "number of columns missing or invalid");
+      read_field(csa);
+      if (!(str2int(csa->field, &nnz) == 0 && nnz >= 0))
+         error(csa, "number of constraint coefficients missing or inval"
+            "id");
+      if (m > 0)
+      {  glp_add_rows(P, m);
+         for (i = 1; i <= m; i++)
+            glp_set_row_bnds(P, i, GLP_FX, 0.0, 0.0);
+      }
+      if (n > 0)
+      {  glp_add_cols(P, n);
+         for (j = 1; j <= n; j++)
+         {  if (!mip)
+               glp_set_col_bnds(P, j, GLP_LO, 0.0, 0.0);
+            else
+               glp_set_col_kind(P, j, GLP_BV);
+         }
+      }
+      end_of_line(csa);
+      /* allocate working arrays */
+      rf = xcalloc(1+m, sizeof(char));
+      memset(rf, 0, 1+m);
+      cf = xcalloc(1+n, sizeof(char));
+      memset(cf, 0, 1+n);
+      ln = xcalloc(1+nnz, sizeof(int));
+      ia = xcalloc(1+nnz, sizeof(int));
+      ja = xcalloc(1+nnz, sizeof(int));
+      ar = xcalloc(1+nnz, sizeof(double));
+      /* read descriptor lines */
+      ne = 0;
+      for (;;)
+      {  read_designator(csa);
+         if (strcmp(csa->field, "i") == 0)
+         {  /* row descriptor */
+            read_field(csa);
+            if (str2int(csa->field, &i) != 0)
+               error(csa, "row number missing or invalid");
+            if (!(1 <= i && i <= m))
+               error(csa, "row number out of range");
+            read_field(csa);
+            if (strcmp(csa->field, "f") == 0)
+               type = GLP_FR;
+            else if (strcmp(csa->field, "l") == 0)
+               type = GLP_LO;
+            else if (strcmp(csa->field, "u") == 0)
+               type = GLP_UP;
+            else if (strcmp(csa->field, "d") == 0)
+               type = GLP_DB;
+            else if (strcmp(csa->field, "s") == 0)
+               type = GLP_FX;
+            else
+               error(csa, "row type missing or invalid");
+            if (type == GLP_LO || type == GLP_DB || type == GLP_FX)
+            {  read_field(csa);
+               if (str2num(csa->field, &lb) != 0)
+                  error(csa, "row lower bound/fixed value missing or in"
+                     "valid");
+            }
+            else
+               lb = 0.0;
+            if (type == GLP_UP || type == GLP_DB)
+            {  read_field(csa);
+               if (str2num(csa->field, &ub) != 0)
+                  error(csa, "row upper bound missing or invalid");
+            }
+            else
+               ub = 0.0;
+            if (rf[i] & 0x01)
+               error(csa, "duplicate row descriptor");
+            glp_set_row_bnds(P, i, type, lb, ub), rf[i] |= 0x01;
+         }
+         else if (strcmp(csa->field, "j") == 0)
+         {  /* column descriptor */
+            read_field(csa);
+            if (str2int(csa->field, &j) != 0)
+               error(csa, "column number missing or invalid");
+            if (!(1 <= j && j <= n))
+               error(csa, "column number out of range");
+            if (!mip)
+               kind = GLP_CV;
+            else
+            {  read_field(csa);
+               if (strcmp(csa->field, "c") == 0)
+                  kind = GLP_CV;
+               else if (strcmp(csa->field, "i") == 0)
+                  kind = GLP_IV;
+               else if (strcmp(csa->field, "b") == 0)
+               {  kind = GLP_IV;
+                  type = GLP_DB, lb = 0.0, ub = 1.0;
+                  goto skip;
+               }
+               else
+                  error(csa, "column kind missing or invalid");
+            }
+            read_field(csa);
+            if (strcmp(csa->field, "f") == 0)
+               type = GLP_FR;
+            else if (strcmp(csa->field, "l") == 0)
+               type = GLP_LO;
+            else if (strcmp(csa->field, "u") == 0)
+               type = GLP_UP;
+            else if (strcmp(csa->field, "d") == 0)
+               type = GLP_DB;
+            else if (strcmp(csa->field, "s") == 0)
+               type = GLP_FX;
+            else
+               error(csa, "column type missing or invalid");
+            if (type == GLP_LO || type == GLP_DB || type == GLP_FX)
+            {  read_field(csa);
+               if (str2num(csa->field, &lb) != 0)
+                  error(csa, "column lower bound/fixed value missing or"
+                     " invalid");
+            }
+            else
+               lb = 0.0;
+            if (type == GLP_UP || type == GLP_DB)
+            {  read_field(csa);
+               if (str2num(csa->field, &ub) != 0)
+                  error(csa, "column upper bound missing or invalid");
+            }
+            else
+               ub = 0.0;
+skip:       if (cf[j] & 0x01)
+               error(csa, "duplicate column descriptor");
+            glp_set_col_kind(P, j, kind);
+            glp_set_col_bnds(P, j, type, lb, ub), cf[j] |= 0x01;
+         }
+         else if (strcmp(csa->field, "a") == 0)
+         {  /* coefficient descriptor */
+            read_field(csa);
+            if (str2int(csa->field, &i) != 0)
+               error(csa, "row number missing or invalid");
+            if (!(0 <= i && i <= m))
+               error(csa, "row number out of range");
+            read_field(csa);
+            if (str2int(csa->field, &j) != 0)
+               error(csa, "column number missing or invalid");
+            if (!((i == 0 ? 0 : 1) <= j && j <= n))
+               error(csa, "column number out of range");
+            read_field(csa);
+            if (i == 0)
+            {  if (str2num(csa->field, &temp) != 0)
+                  error(csa, "objective %s missing or invalid",
+                     j == 0 ? "constant term" : "coefficient");
+               if (cf[j] & 0x10)
+                  error(csa, "duplicate objective %s",
+                     j == 0 ? "constant term" : "coefficient");
+               glp_set_obj_coef(P, j, temp), cf[j] |= 0x10;
+            }
+            else
+            {  if (str2num(csa->field, &temp) != 0)
+                  error(csa, "constraint coefficient missing or invalid"
+                     );
+               if (ne == nnz)
+                  error(csa, "too many constraint coefficient descripto"
+                     "rs");
+               ln[++ne] = csa->count;
+               ia[ne] = i, ja[ne] = j, ar[ne] = temp;
+            }
+         }
+         else if (strcmp(csa->field, "n") == 0)
+         {  /* symbolic name descriptor */
+            read_field(csa);
+            if (strcmp(csa->field, "p") == 0)
+            {  /* problem name */
+               read_field(csa);
+               if (P->name != NULL)
+                  error(csa, "duplicate problem name");
+               glp_set_prob_name(P, csa->field);
+            }
+            else if (strcmp(csa->field, "z") == 0)
+            {  /* objective name */
+               read_field(csa);
+               if (P->obj != NULL)
+                  error(csa, "duplicate objective name");
+               glp_set_obj_name(P, csa->field);
+            }
+            else if (strcmp(csa->field, "i") == 0)
+            {  /* row name */
+               read_field(csa);
+               if (str2int(csa->field, &i) != 0)
+                  error(csa, "row number missing or invalid");
+               if (!(1 <= i && i <= m))
+                  error(csa, "row number out of range");
+               read_field(csa);
+               if (P->row[i]->name != NULL)
+                  error(csa, "duplicate row name");
+               glp_set_row_name(P, i, csa->field);
+            }
+            else if (strcmp(csa->field, "j") == 0)
+            {  /* column name */
+               read_field(csa);
+               if (str2int(csa->field, &j) != 0)
+                  error(csa, "column number missing or invalid");
+               if (!(1 <= j && j <= n))
+                  error(csa, "column number out of range");
+               read_field(csa);
+               if (P->col[j]->name != NULL)
+                  error(csa, "duplicate column name");
+               glp_set_col_name(P, j, csa->field);
+            }
+            else
+               error(csa, "object designator missing or invalid");
+         }
+         else if (strcmp(csa->field, "e") == 0)
+            break;
+         else
+            error(csa, "line designator missing or invalid");
+         end_of_line(csa);
+      }
+      if (ne < nnz)
+         error(csa, "too few constraint coefficient descriptors");
+      xassert(ne == nnz);
+      k = glp_check_dup(m, n, ne, ia, ja);
+      xassert(0 <= k && k <= nnz);
+      if (k > 0)
+      {  csa->count = ln[k];
+         error(csa, "duplicate constraint coefficient");
+      }
+      glp_load_matrix(P, ne, ia, ja, ar);
+      /* print some statistics */
+      if (P->name != NULL)
+         xprintf("Problem: %s\n", P->name);
+      if (P->obj != NULL)
+         xprintf("Objective: %s\n", P->obj);
+      xprintf("%d row%s, %d column%s, %d non-zero%s\n",
+         m, m == 1 ? "" : "s", n, n == 1 ? "" : "s", nnz, 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_sort_matrix(P);
+      ret = 0;
+done: if (csa->fp != NULL) xfclose(csa->fp);
+      if (rf != NULL) xfree(rf);
+      if (cf != NULL) xfree(cf);
+      if (ln != NULL) xfree(ln);
+      if (ia != NULL) xfree(ia);
+      if (ja != NULL) xfree(ja);
+      if (ar != NULL) xfree(ar);
+      if (ret) glp_erase_prob(P);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_write_prob - write problem data in GLPK format
+*
+*  SYNOPSIS
+*
+*  int glp_write_prob(glp_prob *P, int flags, const char *fname);
+*
+*  The routine glp_write_prob writes problem data in GLPK LP/MIP format
+*  to a text file.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine returns zero. Otherwise
+*  it prints an error message and returns non-zero. */
+
+int glp_write_prob(glp_prob *P, int flags, const char *fname)
+{     XFILE *fp;
+      GLPROW *row;
+      GLPCOL *col;
+      GLPAIJ *aij;
+      int mip, i, j, count, ret;
+      if (P == NULL || P->magic != GLP_PROB_MAGIC)
+         xerror("glp_write_prob: P = %p; invalid problem object\n",
+            P);
+      if (flags != 0)
+         xerror("glp_write_prob: flags = %d; invalid parameter\n",
+            flags);
+      if (fname == NULL)
+         xerror("glp_write_prob: fname = %d; invalid parameter\n",
+            fname);
+      xprintf("Writing problem data to `%s'...\n", fname);
+      fp = xfopen(fname, "w"), count = 0;
+      if (fp == NULL)
+      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      /* write problem line */
+      mip = (glp_get_num_int(P) > 0);
+      xfprintf(fp, "p %s %s %d %d %d\n", !mip ? "lp" : "mip",
+         P->dir == GLP_MIN ? "min" : P->dir == GLP_MAX ? "max" : "???",
+         P->m, P->n, P->nnz), count++;
+      if (P->name != NULL)
+         xfprintf(fp, "n p %s\n", P->name), count++;
+      if (P->obj != NULL)
+         xfprintf(fp, "n z %s\n", P->obj), count++;
+      /* write row descriptors */
+      for (i = 1; i <= P->m; i++)
+      {  row = P->row[i];
+         if (row->type == GLP_FX && row->lb == 0.0)
+            goto skip1;
+         xfprintf(fp, "i %d ", i), count++;
+         if (row->type == GLP_FR)
+            xfprintf(fp, "f\n");
+         else if (row->type == GLP_LO)
+            xfprintf(fp, "l %.*g\n", DBL_DIG, row->lb);
+         else if (row->type == GLP_UP)
+            xfprintf(fp, "u %.*g\n", DBL_DIG, row->ub);
+         else if (row->type == GLP_DB)
+            xfprintf(fp, "d %.*g %.*g\n", DBL_DIG, row->lb, DBL_DIG,
+                  row->ub);
+         else if (row->type == GLP_FX)
+            xfprintf(fp, "s %.*g\n", DBL_DIG, row->lb);
+         else
+            xassert(row != row);
+skip1:   if (row->name != NULL)
+            xfprintf(fp, "n i %d %s\n", i, row->name), count++;
+      }
+      /* write column descriptors */
+      for (j = 1; j <= P->n; j++)
+      {  col = P->col[j];
+         if (!mip && col->type == GLP_LO && col->lb == 0.0)
+            goto skip2;
+         if (mip && col->kind == GLP_IV && col->type == GLP_DB &&
+             col->lb == 0.0 && col->ub == 1.0)
+            goto skip2;
+         xfprintf(fp, "j %d ", j), count++;
+         if (mip)
+         {  if (col->kind == GLP_CV)
+               xfprintf(fp, "c ");
+            else if (col->kind == GLP_IV)
+               xfprintf(fp, "i ");
+            else
+               xassert(col != col);
+         }
+         if (col->type == GLP_FR)
+            xfprintf(fp, "f\n");
+         else if (col->type == GLP_LO)
+            xfprintf(fp, "l %.*g\n", DBL_DIG, col->lb);
+         else if (col->type == GLP_UP)
+            xfprintf(fp, "u %.*g\n", DBL_DIG, col->ub);
+         else if (col->type == GLP_DB)
+            xfprintf(fp, "d %.*g %.*g\n", DBL_DIG, col->lb, DBL_DIG,
+                  col->ub);
+         else if (col->type == GLP_FX)
+            xfprintf(fp, "s %.*g\n", DBL_DIG, col->lb);
+         else
+            xassert(col != col);
+skip2:   if (col->name != NULL)
+            xfprintf(fp, "n j %d %s\n", j, col->name), count++;
+      }
+      /* write objective coefficient descriptors */
+      if (P->c0 != 0.0)
+         xfprintf(fp, "a 0 0 %.*g\n", DBL_DIG, P->c0), count++;
+      for (j = 1; j <= P->n; j++)
+      {  col = P->col[j];
+         if (col->coef != 0.0)
+            xfprintf(fp, "a 0 %d %.*g\n", j, DBL_DIG, col->coef),
+               count++;
+      }
+      /* write constraint coefficient descriptors */
+      for (i = 1; i <= P->m; i++)
+      {  row = P->row[i];
+         for (aij = row->ptr; aij != NULL; aij = aij->r_next)
+            xfprintf(fp, "a %d %d %.*g\n", i, aij->col->j, DBL_DIG,
+               aij->val), count++;
+      }
+      /* write end line */
+      xfprintf(fp, "e o f\n"), count++;
+      xfflush(fp);
+      if (xferror(fp))
+      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      xprintf("%d lines were written\n", count);
+      ret = 0;
+done: if (fp != NULL) xfclose(fp);
+      return ret;
+}
+
+/* eof */