/* nag_stable_sort (m01ctc) Example Program.
 *
 * Copyright 2017 Numerical Algorithms Group.
 *
 * Mark 26.2, 2017.
 */

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nag_stddef.h>
#include <nagm01.h>

#ifdef __cplusplus
extern "C"
{
#endif
  static Integer NAG_CALL compare(const Nag_Pointer a, const Nag_Pointer b);
#ifdef __cplusplus
}
#endif

#define VEC(I, J) vec[(I) *tdvec + J]
int main(void)
{
  Integer exit_status = 0, i, j, k, m, n, tdvec;
  NagError fail;
  double *vec = 0;

  INIT_FAIL(fail);

  /* Skip heading in data file */
  scanf("%*[^\n]");
  printf("nag_stable_sort (m01ctc) Example Program Results\n");
  scanf("%" NAG_IFMT "%" NAG_IFMT "%" NAG_IFMT "", &m, &n, &k);
  if (m >= 0 && n >= 0 && k >= 0 && k <= n) {
    if (!(vec = NAG_ALLOC(m * n, double)))
    {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
    tdvec = n;
  }
  else {
    printf("Invalid m or n or k.\n");
    exit_status = 1;
    return exit_status;
  }
  for (i = 0; i < m; ++i)
    for (j = 0; j < n; ++j)
      scanf("%lf", &VEC(i, j));
  /* nag_stable_sort (m01ctc).
   * Stable sort of set of values of arbitrary data type
   */
  nag_stable_sort((Pointer) &VEC(0, k - 1), (size_t) m, sizeof(double),
                  (ptrdiff_t) (n * sizeof(double)), compare, Nag_Ascending,
                  &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_stable_sort (m01ctc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }

  printf("\nMatrix with column %" NAG_IFMT " sorted\n", k);
  for (i = 0; i < m; ++i) {
    for (j = 0; j < n; ++j)
      printf(" %7.1f ", VEC(i, j));
    printf("\n");
  }
END:
  NAG_FREE(vec);
  return exit_status;
}

static Integer NAG_CALL compare(const Nag_Pointer a, const Nag_Pointer b)
{
  double x = *((const double *) a);
  double y = *((const double *) b);
  return (x < y ? -1 : (x == y ? 0 : 1));
}