#include <stdio.h>
#include "insertsort.h"

node heap[MAX_NODES];
int node_p = 0;

node* new_node() {
  if (node_p == MAX_NODES) {
    return 0;
  }
  return &(heap[node_p++]);
}

node* head;

void initialize() {
  head = NULL;
}

void print_nodes() {
  node* p = head;
  printf ("(");
  while (p != NULL) {
    printf ("%d ", p->v);
    p = p->next;
  }

  printf (")");
}

int is_sorted() {
  node* p = head;
  while (p != NULL) {
    if (p->next != NULL) {
      if (p->v > p->next->v) {
	return 0;
      }
    }
    p = p->next;
  }
  return 1;
}

int insert (int x) {
  node* p = head;
  
  if (p == NULL) {
    head = new_node();
    if (head == NULL) {
      return 0;
    } else {
      head->v = x;
      head->next = NULL;
    }
    
    return 1;
  }

  while ((p->next != NULL) && (p->next->v < x)) {
    p = p->next;
  }

  /* At this point, either p->next == NULL or p->next->v >= x) */

  if (p->next == NULL) {
    p->next = new_node();
    if (p->next == NULL) {
      return 0;
    } else {
      p->next->v = x;
      p->next->next = NULL;
    }
    return 1;
  } else {
    node* t = new_node();
    if (t == NULL) {
      return 0;
    } else {
      t->v = x;
      t->next = p->next;
      p->next = t;
    }
    return 1;
  }

  return -1;
}