Esempio n. 1
0
void NonCollisionHashTable::rebuild()
{
  clear();
  setSize(keys.getSize() * keys.getSize());
  generateUniversalHashFunction(table.size(), primeNumber, hash);

  if (!keys.isEmpty())
  {
    MyNode<int>* it = keys.getBegin();
    while (it != 0)
    {        
      if (!simpleInsert(it->item))
      {
        it = keys.getBegin();
        clear();
        generateUniversalHashFunction(table.size(), primeNumber, hash);          
      }
      else
      {
        it = it->next;
      }
    }
  }
  needRebuild = false;
}
Esempio n. 2
0
void FixedSet::Initialize(const vector<int>& numbers)
{  
  size_t sizeOfSecondTables = 0;
  size_t tableSize = numbers.size();
  MyList<size_t> secondTablesForRebuild;

/*  clock_t t1 = clock();*/
  secondHashTables.resize(tableSize);
//   clock_t t2 = clock();
//   cout << (double)(t2 - t1) / CLOCKS_PER_SEC << endl;

  generateUniversalHashFunction(tableSize, primeNumber, hash);
  
  for (size_t index = 0; index < tableSize; ++index)
  {
    size_t hashValue = hash(numbers[index]);

    if (!secondHashTables[hashValue].insert(numbers[index]))
    {
      if (!secondHashTables[hashValue].isNeedRebuild())
      {
        secondHashTables[hashValue].setRebuild(true);
        secondTablesForRebuild.pushFront(hashValue);
      }
      --sizeOfSecondTables;
    }
    else
    {
      ++sizeOfSecondTables;
    }
  }

  MyNode<size_t>* it = secondTablesForRebuild.getBegin();
  for (; it != 0 && !secondTablesForRebuild.isEmpty(); it = it->next)
  {
    size_t indexOfSecondHashTable = it->item;
    secondHashTables[indexOfSecondHashTable].rebuild();

    size_t secondTableSize = secondHashTables[indexOfSecondHashTable].getSize();
    sizeOfSecondTables += secondTableSize;
  }

  if (sizeOfSecondTables > 4 * tableSize)
  {
    for (size_t index = 0; index < tableSize; ++index)
    {
      if (!secondHashTables[index].isEmpty())
      {
        secondHashTables[index].clear();
        secondHashTables[index].deleteKeys();
        secondHashTables[index].setRebuild(false);
        secondHashTables[index].setSize(0);
        secondHashTables[index].setEmpty(true);
      }
    }
    Initialize(numbers);
  }  
}
Esempio n. 3
0
void NonCollisionHashTable::clear()
{
  if (!keys.isEmpty())
  {
    MyNode<int>* it = keys.getBegin();
    bool empty = table[hash(it->item)].second;

    for (; it != 0 && !empty; it = it->next)
    {
      empty = table[hash(it->item)].second;
      table[hash(it->item)] = make_pair<int, bool>(0, true);
    }
  }
}