/* nag_search_vector (m01fsc) Example Program.
 *
 * Copyright 1990 Numerical Algorithms Group.
 *
 * Mark 2 revised, 1992.
 * Mark 5 revised, 1998.
 * Mark 7 revised, 2001.
 * Mark 8 revised, 2004.
 *
 */

#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)
{
  double x = *((const double *) a);
  double y = *((const double *) b);
  return(x < y?-1:(x == y?0:1));
}
#ifdef __cplusplus
}
#endif


int main(void)
{
  Integer  exit_status = 0;
  NagError fail;
  Pointer  match;
  double   key, *vec = 0;
  size_t   i, n;

  INIT_FAIL(fail);

  /* Skip heading in data file */
  scanf("%*[^\n]");
  printf("nag_search_vector (m01fsc) Example Program Results\n");
  /* Read number of points and number to search for */
  scanf("%" NAG_UFMT "%lf", &n, &key);
  if (n >= 1)
    {
      if (!(vec = NAG_ALLOC(50, double)))
        {
          printf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      printf("Invalid n.\n");
      exit_status = 1;
      return exit_status;
    }
  for (i = 0; i < n; ++i)
    scanf("%lf", &vec[i]);
  /* nag_search_vector (m01fsc).
   * Searches a vector for either the first or last match to a
   * given value
   */
  if (nag_search_vector((Pointer) &key, (Pointer) vec, n,
                        (ptrdiff_t)(sizeof(double)), compare, Nag_Ascending,
                        Nag_First, &match, &fail))
    {
      printf("Exact match found: ");
      if (fail.code != NE_NOERROR)
        {
          printf("Error from nag_search_vector (m01fsc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
      printf("First match index: %u\n",
             (unsigned long)((double *) match - vec));
    }
  else
    {
      printf("No exact match found: ");
      if (match != NULL)
        printf("Nag_First nearest match index = %u\n",
               (unsigned long)((double *) match - vec));
      else
        printf("No match in the input array\n");
    }
 END:
  if (vec) NAG_FREE(vec);
  return exit_status;
}