public MaxHeap(T[] entries)
{
   this(entries.length); // Call previous constructor
   assert initialized = true;

   // Copy given array to data field
   for (int index = 0; index < entries.length; index++)
      heap[index + 1] = entries[index];

   // Create heap
   for (int rootIndex = lastIndex / 2; rootIndex > 0; rootIndex--)
      reheap(rootIndex);
} // end constructor
// Version 4.0