heap.C

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class manheap;
class maxHeap;
#include <iostream>
using namespace std;
#include "heap.h"
// Heap of pointers. The field to be compared is:

minHeap::minHeap(int size)
{
  this->size = size;
  h = new heapRecord[size];
  count = 0;
}

minHeap::~minHeap() {
  delete [] h;
}

int minHeap::numElements()
{
  return count;
}

int minHeap::insert(InfoRecord *x)
{
  h[count].info = x;
  h[count].deleted = 0;

  int current = count;
  count++;

  if (count >= size) {
    std::cout << "minHeap overflow. \n" ; 
    return -1;}

  int parent = (current - 1)/2;
  while (current != 0)
    {
      if (h[current].info->load < h[parent].info->load)
        {
          swap(current, parent);
          current = parent;
          parent = (current-1)/2;
        }
      else
        break;
    }
  return 0;
}

InfoRecord *minHeap::deleteMin()
{
  if (count == 0) return 0;

  InfoRecord *tmp = h[0].info;
  int best;

  h[0] = h[count-1];
  count--;

  int current = 0;
  int c1 = 1;
  int c2 = 2;
  while (c1 < count)
    {
      if (c2 >= count)
        best = c1;
      else
        {
          if (h[c1].info->load < h[c2].info->load)
            best = c1;
          else
            best = c2;
        }
      if (h[best].info->load < h[current].info->load)
        {
          swap(best, current);
          current = best;
          c1 = 2*current + 1;
          c2 = c1 + 1;
        }
      else
        break;
    }
  return tmp;
}

InfoRecord *minHeap::iterator(heapIterator *iter){
  iter->next = 1;
  if (count == 0)
    return 0;
  return h[0].info;
}
InfoRecord *minHeap::next(heapIterator *iter){
  if (iter->next >= count)
    return 0;
  iter->next += 1;
  return h[iter->next - 1].info;
}

//*****************


maxHeap::maxHeap(int size)
{
  this->size = size;
  h = new heapRecord[size];
  count = 0;
}

maxHeap::~maxHeap() {
  delete [] h;
}

int maxHeap::numElements()
{
  return count;
}

int maxHeap::insert(InfoRecord *x)
{
  h[count].info = x;
  h[count].deleted  = 0;
  int current = count;
  count++;

  if (count >= size) {
    std::cout << "maxHeap overflow. \n" ; 
    return -1;}

  int parent = (current - 1)/2;
  while (current != 0)
    {
      if (h[current].info->load > h[parent].info->load)
        {
          swap(current, parent);
          current = parent;
          parent = (current-1)/2;
        }
      else
        break;
    }
  return 0;
}

InfoRecord *maxHeap::deleteMax()
{
  if (count == 0) return 0;
  InfoRecord *tmp = h[0].info;
  int best;

  h[0] = h[count-1];
  count--;

  int current = 0;
  int c1 = 1;
  int c2 = 2;
  while (c1 < count)
    {
      if (c2 >= count)
        best = c1;
      else
        {
          if (h[c1].info->load > h[c2].info->load)
            best = c1;
          else
            best = c2;
        }
      if (h[best].info->load > h[current].info->load)
        {
          swap(best, current);
          current = best;
          c1 = 2*current + 1;
          c2 = c1 + 1;
        }
      else
        break;
    }
  return tmp;
}


InfoRecord *maxHeap::iterator(heapIterator *iter){
  iter->next = 1;
  if (count == 0)
    return 0;
  return h[0].info;
}

InfoRecord *maxHeap::next(heapIterator *iter){
  if (iter->next >= count)
    return 0;
  iter->next += 1;
  return h[iter->next - 1].info;
}

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