cutil/oldheap.cpp

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/* =================
          Include Files and Type Defines
 ==================== */
#include "oldheap.h"
#include "freelist.h"
#include "danerror.h"
#include "emalloc.h"
#include <stdio.h>

#define FATHER(N) ((N)>>1)
#define LEFTSON(N)  ((N)<<1)
#define RIGHTSON(N) ((N)<<1 + 1)

/* =================
    Public Code
 ==================== */
/* =============================== */
HEAP *MakeHeap(int Size) { 
  HEAP *NewHeap;

  NewHeap = (HEAP *) Emalloc (sizeof (HEAP) + Size * sizeof (HEAPENTRY));

  NewHeap->Size = Size;
  NewHeap->FirstFree = 1;
  return (NewHeap);
}                                /* MakeHeap */


/* =============================== */
int HeapPop(HEAP *Heap, FLOAT32 *Key, void *out_ptr) { 
  INT32 Hole;
  FLOAT32 HoleKey;
  INT32 Son;
  void **Data = (void **) out_ptr;

  if (Heap->FirstFree <= 1)
    return (EMPTY);

  *Key = Heap->Entry[1].Key;
  *Data = Heap->Entry[1].Data;

  Heap->FirstFree--;

  /* imagine the hole at the root is filled with the last entry in the heap */
  HoleKey = Heap->Entry[Heap->FirstFree].Key;
  Hole = 1;

                                 /* while hole has 2 sons */
  while ((Son = LEFTSON (Hole)) < Heap->FirstFree) {
    /* find the son with the smallest key */
    if (Heap->Entry[Son].Key > Heap->Entry[Son + 1].Key)
      Son++;

    /* if key for hole is greater than key for son, sift hole down */
    if (HoleKey > Heap->Entry[Son].Key) {
      Heap->Entry[Hole].Key = Heap->Entry[Son].Key;
      Heap->Entry[Hole].Data = Heap->Entry[Son].Data;
      Hole = Son;
    }
    else
      break;
  }
  Heap->Entry[Hole].Key = HoleKey;
  Heap->Entry[Hole].Data = Heap->Entry[Heap->FirstFree].Data;
  return (OK);
}                                /* HeapPop */


/* =============================== */
int HeapPopWorst(HEAP *Heap, FLOAT32 *Key, void *out_ptr) { 
  INT32 Index;                   /*current index */
  INT32 Hole;
  FLOAT32 HoleKey;
  INT32 Father;
  void *HoleData;
  void **Data = (void **) out_ptr;

  if (Heap->FirstFree <= 1)
    return (EMPTY);

  HoleKey = Heap->Entry[1].Key;
  Hole = 1;
  Heap->FirstFree--;
  for (Index = Heap->FirstFree, Father = FATHER (Index); Index > Father;
    Index--)
  if (Heap->Entry[Index].Key > HoleKey) {
                                 /*find biggest */
    HoleKey = Heap->Entry[Index].Key;
    Hole = Index;
  }
  *Key = HoleKey;
  *Data = Heap->Entry[Hole].Data;

  HoleKey = Heap->Entry[Heap->FirstFree].Key;
  Heap->Entry[Hole].Key = HoleKey;
  HoleData = Heap->Entry[Heap->FirstFree].Data;
  Heap->Entry[Hole].Data = HoleData;

  /* now sift last entry to its rightful place */
  Father = FATHER (Hole);        /*father of hole */
  while (Hole > 1 && Heap->Entry[Father].Key > HoleKey) {
                                 /*swap entries */
    Heap->Entry[Hole].Key = Heap->Entry[Father].Key;
    Heap->Entry[Hole].Data = Heap->Entry[Father].Data;
    Heap->Entry[Father].Data = HoleData;
    Heap->Entry[Father].Key = HoleKey;
    Hole = Father;
    Father = FATHER (Hole);
  }
  return (OK);
}                                /* HeapPop */


/* =============================== */
void HeapPush(HEAP *Heap, FLOAT32 Key, void *Data) { 
  INT32 Item;
  INT32 Father;

  if (Heap->FirstFree > Heap->Size)
    DoError (HEAPFULL, "Heap size exceeded");

  Item = Heap->FirstFree;
  Heap->FirstFree++;
  while (Item != 1) {
    Father = FATHER (Item);
    if (Heap->Entry[Father].Key > Key) {
      Heap->Entry[Item].Key = Heap->Entry[Father].Key;
      Heap->Entry[Item].Data = Heap->Entry[Father].Data;
      Item = Father;
    }
    else
      break;
  }
  Heap->Entry[Item].Key = Key;
  Heap->Entry[Item].Data = Data;
}                                /* HeapPush */


/* =============================== */
void HeapStore(HEAP *Heap, HEAPENTRY *Entry) { 
  INT32 Item;
  INT32 Father;

  if (Heap->FirstFree > Heap->Size)
    DoError (HEAPFULL, "Heap size exceeded");

  Item = Heap->FirstFree;
  Heap->FirstFree++;
  while (Item != 1) {
    Father = FATHER (Item);
    if (Heap->Entry[Father].Key > Entry->Key) {
      Heap->Entry[Item].Key = Heap->Entry[Father].Key;
      Heap->Entry[Item].Data = Heap->Entry[Father].Data;
      Item = Father;
    }
    else
      break;
  }
  Heap->Entry[Item].Key = Entry->Key;
  Heap->Entry[Item].Data = Entry->Data;
}                                /* HeapStore */


/* =============================== */
int GetTopOfHeap(HEAP *Heap, HEAPENTRY *Entry) { 
  INT32 Hole;
  FLOAT32 HoleKey;
  INT32 Son;

  if (Heap->FirstFree <= 1)
    return (EMPTY);

  Entry->Key = Heap->Entry[1].Key;
  Entry->Data = Heap->Entry[1].Data;

  Heap->FirstFree--;

  /* imagine the hole at the root is filled with the last entry in the heap */
  HoleKey = Heap->Entry[Heap->FirstFree].Key;
  Hole = 1;

                                 /* while hole has 2 sons */
  while ((Son = LEFTSON (Hole)) < Heap->FirstFree) {
    /* find the son with the smallest key */
    if (Heap->Entry[Son].Key > Heap->Entry[Son + 1].Key)
      Son++;

    /* if key for hole is greater than key for son, sift hole down */
    if (HoleKey > Heap->Entry[Son].Key) {
      Heap->Entry[Hole].Key = Heap->Entry[Son].Key;
      Heap->Entry[Hole].Data = Heap->Entry[Son].Data;
      Hole = Son;
    }
    else
      break;
  }
  Heap->Entry[Hole].Key = HoleKey;
  Heap->Entry[Hole].Data = Heap->Entry[Heap->FirstFree].Data;
  return (OK);
}                                /* GetTopOfHeap */


/* =============================== */
void FreeHeapData(HEAP *Heap, void_dest destructor) { 
  HEAPENTRY Entry;

  while (GetTopOfHeap (Heap, &Entry) != EMPTY)
    destructor (Entry.Data);

  FreeHeap(Heap); 
}                                /* FreeHeapData */

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