/* Written by Dale Bryant for 6121 - Computer Science II at
   Hudson Valley Community College - http://www.hvcc.edu/~bryandal/

   Templated by Warren M Myers

   Upshift feature added 6 Feb 2001
      deletes the first block.. run again for multiple deletions
      same effect as sliding all values up BLOCKSIZE, blowing away first BLOCKSIZE
   Insert feature added 15 Dec 2001
      inserts a new chunk of BLOCKSIZE added to list at front end
*/

#ifndef _IA_PUB_H_
#define _IA_PUB_H_

using namespace std;
#include <string>

template <class IA, int BLOCKSIZE=7>
class InfiniteArray{
private:
  class Node{
  public:
    Node(){
      next = NULL;}
    IA
      data[BLOCKSIZE];
    Node *next;
  };

  Node *start;

  bool upshift(){
    Node *t = start->next;
    if(NULL==t)
      return false;
    start = start->next;
    delete t;
    return true;
  }
  bool insert(){
    Node *t = new Node;
    if(NULL==t){
      cerr << "Infinite Array put Out of Memory";
      return false;
    }
    t->next = start->next;
    start->next = t;
    return true;
  }

public:
  typedef Node* NPtr;

  InfiniteArray(){
    start = new Node;}

  ~InfiniteArray(){
    NPtr
      tmp = start;
    while (NULL!=tmp){
      delete tmp;
      start = start->next;
      tmp = start;
    }
  }

  IA & operator[](int index){
    NPtr
      curptr=start;
    int
      ci = index;
    while (BLOCKSIZE<=ci){
      if (NULL==curptr->next){
        curptr->next = new Node;
        if (NULL==curptr){
          cerr << "Infinite Array put Out of Memory \n";
          exit(1);
        }
      }
      curptr = curptr->next;
      ci -= BLOCKSIZE;
    }
    return( curptr->data[ci]);
  }

  bool operator--(){
    return upshift();}
  bool operator++(){
    return insert();}
};

#endif