#ifndef _ARRAY_H_
#define _ARRAY_H_
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

// ======================================================================
// A resizing array.  but remove is slow & changes the element order.

template <class ARRAY_ELEMENT>
class Array {

public:

  Array(int s) {
    assert (s > 0);
    size = s;
    count = 0;
    data = new ARRAY_ELEMENT [size]; }
  virtual ~Array() { 
    delete [] data; 
    data = NULL; }

  // =========
  // ACCESSORS
  int Count() const { return count; }  
  ARRAY_ELEMENT operator [] (int i) const {
    assert (i >= 0 && i < count);
    return data[i]; }
  
  // =========
  // MODIFIERS
  void Add(const ARRAY_ELEMENT elem) {
    if (count == size) {
      // double the space & copy 
      int new_size = size*2;
      //printf ("need to resize array from %d to %d\n", size, new_size);
      ARRAY_ELEMENT * new_data = new ARRAY_ELEMENT [new_size];
      for (int i = 0; i < size; i++) {
	new_data[i] = data[i];
      }
      delete [] data;
      data = new_data;
      size = new_size;
    }
    assert (count < size);
    data[count] = elem;
    count++;
  }

  void AddNoDuplicates(const ARRAY_ELEMENT e) { if (!Member(e)) Add(e); }

  ARRAY_ELEMENT Replace(int i, const ARRAY_ELEMENT elem) {
    assert(i >= 0 && i < count);
    ARRAY_ELEMENT answer = data[i];
    data[i] = elem;
    return answer;
  }

  void Remove(const ARRAY_ELEMENT elem) {
    int x = -1;
    for (int i = 0; i < count; i++) {
      if (data[i] == elem) {
	x = i;
	break;
      }
    }
    assert (x >= 0);
    data[x] = data[count-1];
    count--;    
  }

  int Member(const ARRAY_ELEMENT elem) const {
    int x = -1;
    for (int i = 0; i < count; i++) {
      if (data[i] == elem) {
	x = i;
	break;
      }
    }
    if (x >= 0) return 1;
    return 0;
  }

  void Clear() {
    count = 0;
  }

  void DeleteAllElements() {
    for (int i = 0; i < count; i++) {
      delete data[i];
    }
    count = 0;
  }

private:

  // ==============
  // REPRESENTATION
  int count;
  int size;
  ARRAY_ELEMENT * data;

};


#endif