/* nag_rand_permute (g05ncc) Example Program.
 *
 * Copyright 2008, Numerical Algorithms Group.
 *
 * Mark 9, 2009.
 */
/* Pre-processor includes */
#include <stdio.h>
#include <math.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagg05.h>

int main(int argc, char *argv[])
{
  FILE        *fpout;
  /* Integer scalar and array declarations */
  Integer     exit_status = 0;
  Integer     i, j, lstate;
  Integer     *index = 0, *state = 0;

  /* NAG structures */
  NagError    fail;

  /* Number of permutations*/
  Integer     m = 10;

  /* Sample size */
  Integer     n = 8;

  /* Choose the base generator */
  Nag_BaseRNG genid = Nag_Basic;
  Integer     subid = 0;

  /* Set the seed */
  Integer     seed[] = { 1762543 };
  Integer     lseed = 1;

  /* Initialise the error structure */
  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpout = nag_example_file_io(argc, argv, "-results", NULL);

  fprintf(fpout, "nag_rand_permute (g05ncc) Example Program Results\n\n");

  /* Get the length of the state array */
  lstate = -1;
  nag_rand_init_repeatable(genid, subid, seed, lseed, state, &lstate, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_rand_init_repeatable (g05kfc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Allocate arrays */
  if (!(index = NAG_ALLOC(n, Integer)) ||
      !(state = NAG_ALLOC(lstate, Integer)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  /* Initialise the generator to a repeatable sequence */
  nag_rand_init_repeatable(genid, subid, seed, lseed, state, &lstate, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_rand_init_repeatable (g05kfc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  fprintf(fpout, " %2ld Permutations of first %1ld integers\n",
          m, n);

  /* Permutate M times */
  for (j = 0; j < m; j++)
    {
      /* Set up the index vector */
      for (i = 0; i < n; i++)
        index[i] = i + 1;

      /* Call the permutation routine*/
      nag_rand_permute(index, n, state, &fail);
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout, "Error from nag_rand_permute (g05ncc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }

      /* Display the results */
      fprintf(fpout, "  ");
      for (i = 0; i < n; i++)
        fprintf(fpout, "%2ld%s", index[i], (i + 1)%8?" ":"\n");
      if (n%8) fprintf(fpout, "\n");
    }

 END:
  if (fpout != stdout) fclose(fpout);
  if (index) NAG_FREE(index);
  if (state) NAG_FREE(state);

  return exit_status;
}