/* ================================================================

   Loads the nodes of a previously stored BSST from a binary file.
   Constructs a binary search sequence tree and
   then the BSST is traversed in in-order fashion and
   the sorted list is printed.  Compile as
       gcc -ansi inpfile.c  -o objfile

   Prabu 3/15/94

   ================================================================ */

#include	<stdio.h>

#define  FNAMELEN  15     /* maximum length of the filename */

struct node
{
  int info;
  struct node *left;   /* left child */
  struct node *right;  /* right child */
};

const int nodesize = sizeof(struct node); /* in bytes */

int getfile(char *message, FILE **fp, char *mode)
/* get the file and open it */
{
  char filename[FNAMELEN + 1];
  int i;
  printf("%s filename : ",message);
  scanf("%s",filename);
  if ((*fp = fopen(filename,mode)) == NULL)
  {
    printf("can't open %s \n",filename);
    return(-1);
  }
  return(0);
}

void inorder(struct node *r) /* print the integers in sorted form */
{
  if (r != NULL)
  {
    inorder(r->left);
    printf(" %d ", r->info);
    inorder(r->right);
  }
  return;
}

void preordload(struct node **r, FILE **f)
/* load the node in binary format from the file -- preorder fashion */
{
  struct node *p;

  p = (struct node *) malloc(nodesize);    /* make a new node */
  if (fread(p, nodesize, 1, *f)) {
    *r = p;
    if ((*r)->left)
      preordload(&(*r)->left, f);
    if ((*r)->right)
      preordload(&(*r)->right, f);
  }
  return;
}

main()
{
  struct node *root, *p;
  int n;
  FILE *fp;

  root = NULL;

  if (getfile("Input",&fp,"rb") < 0)
    return;

  preordload(&root, &fp);
  printf("This binary search sequence tree is loaded from the file \n");

  printf("\nSorted numbers are :\n");
  inorder(root);
  printf("\n\n");
}