/* nag_sort_realvec_vec_search (m01ndc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.2, 2024.
 */

#include <nag.h>
#include <stdio.h>

static int ex1(double *rv, Integer n, Integer m1, Integer m2, double *item,
               Integer m);
static int ex2(double *rv, Integer n, Integer m1, Integer m2, double *item,
               Integer m);

int main(void) {

  /* Scalars */
  Integer exit_status = 0;
  Integer exit_status_ex1 = 0;
  Integer exit_status_ex2 = 0;
  Integer i, n, m1, m2, m;

  /* Arrays */
  double *item = 0, *rv = 0;

  printf("nag_sort_realvec_vec_search (m01ndc) Example Program Results\n");
  printf("\n");

  /* Read dimensions of arrays from data file */
  scanf("%*[^\n] ");
  scanf("%" NAG_IFMT "%" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &n, &m1, &m2);
  scanf("%" NAG_IFMT "%*[^\n]", &m);

  /* Allocate arrays accordingly */
  if (!(rv = NAG_ALLOC((n), double)) || !(item = NAG_ALLOC((m), double))) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Read array values from data file */
  for (i = 0; i < n; i++) {
    scanf("%lf", &rv[i]);
  }
  scanf("%*[^\n]");

  printf("Vector to be searched is:\n");
  for (i = 0; i < n; i++)
    printf("%7.1f%s", rv[i], (i + 1) % 8 ? " " : "\n");

  for (i = 0; i < m; i++) {
    scanf("%lf", &item[i]);
  }
  scanf("%*[^\n]");

  exit_status_ex1 = ex1(rv, n, m1, m2, item, m);
  exit_status_ex2 = ex2(rv, n, m1, m2, item, m);

END:
  NAG_FREE(rv);
  NAG_FREE(item);

  return (exit_status == 0 && exit_status_ex1 == 0 && exit_status_ex2 == 0) ? 0
                                                                            : 1;
}

/* Example 1: Calling nag_sort_realvec_vec_search with mode=4 */
static int ex1(double *rv, Integer n, Integer m1, Integer m2, double *item,
               Integer m) {

  /* Logicals */
  Nag_Boolean validate;

  /* Scalars */
  Integer exit_status = 0;
  Integer i, mode, lk;
  double h = 0;

  /* Arrays */
  Integer *idx = 0, *k = 0;

  /* Nag Types */
  NagError fail;

  INIT_FAIL(fail);

  /* First call nag_sort_realvec_vec_search with mode=0 and to calculate */
  /* the necessary values for h and lk */
  mode = 0;
  lk = 0;

  if (!(idx = NAG_ALLOC((m), Integer))) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Validate input parameters the first time */
  /* nag_sort_realvec_vec_search is called */
  validate = Nag_TRUE;

  /* nag_sort_realvec_vec_search (m01ndc) */
  /* Search in a set of real numbers using an O(1) method */
  nag_sort_realvec_vec_search(validate, mode, rv, n, m1, m2, item, m, idx, &h,
                              k, &lk, &fail);

  if (fail.code != NE_NOERROR) {
    printf("Error from nag_sort_realvec_vec_search (m01ndc).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }

  /* Allocate k using the value of lk returned in the previous call */
  if (!(k = NAG_ALLOC((lk), Integer))) {
    printf("Allocation failure\n");
    exit_status = -2;
    goto END;
  }

  /* There is no need to validate input parameters again */
  validate = Nag_FALSE;

  /* Call nag_sort_realvec_vec_search with mode=4 to populate k and to */
  /* search rv. */
  mode = 4;

  /* nag_sort_realvec_vec_search (m01ndc), see above */
  nag_sort_realvec_vec_search(validate, mode, rv, n, m1, m2, item, m, idx, &h,
                              k, &lk, &fail);

  if (fail.code != NE_NOERROR) {
    printf("Error from nag_sort_realvec_vec_search (m01ndc).\n%s\n",
           fail.message);
    exit_status = 2;
    goto END;
  }

  printf("\n\nExample 1\n\n");
  for (i = 0; i < m; i++) {
    printf("  Search for item  %7.1f returned index: %4" NAG_IFMT "\n", item[i],
           idx[i]);
  }

END:
  NAG_FREE(k);
  NAG_FREE(idx);

  return exit_status;
}

/* Example 2: Calling nag_sort_realvec_vec_search with mode=3 */
static int ex2(double *rv, Integer n, Integer m1, Integer m2, double *item,
               Integer m) {

  /* Logicals */
  Nag_Boolean validate;

  /* Scalars */
  Integer exit_status = 0;
  Integer i, mode, lk;
  double h = 0;

  /* Arrays */
  Integer *idx = 0, *k = 0;

  /* Nag Types */
  NagError fail;

  INIT_FAIL(fail);

  if (!(idx = NAG_ALLOC((m), Integer))) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Validate input parameters */
  validate = Nag_TRUE;

  /* Mode 3 does not use h or k, so k does not need to be allocated */
  mode = 3;
  h = 0.0;
  lk = 0;

  /* Make a single call to nag_sort_realvec_vec_search to search rv for */
  /* the items without using h or k */

  /* nag_sort_realvec_vec_search (m01ndc) */
  /* Search in a set of real numbers */
  nag_sort_realvec_vec_search(validate, mode, rv, n, m1, m2, item, m, idx, &h,
                              k, &lk, &fail);

  if (fail.code != NE_NOERROR) {
    printf("Error from nag_sort_realvec_vec_search (m01ndc).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }

  printf("\n\nExample 2\n\n");
  for (i = 0; i < m; i++) {
    printf("  Search for item  %7.1f returned index: %4" NAG_IFMT "\n", item[i],
           idx[i]);
  }

END:
  NAG_FREE(idx);

  return exit_status;
}