remove()

s_pair * s_pair_heap::remove

(

)

Definition at line 225 of file spair.cpp.

{
  // Find a non-zero element
  if (nelems == 0) return nullptr;
  int i, first;
  for (first = 0; first <= top_of_heap; first++)
    if (n_in_heap[first] > 0) break;
 
  s_pair *smallest = heap[first];
  // Now find the smallest one
  for (i = first + 1; i <= top_of_heap; i++)
    {
      if (heap[i] == nullptr) continue;
      int cmp = compare(smallest, heap[i]);
      if (cmp > 0)
        {
          first = i;
          smallest = heap[first];
        }
    }
 
  // Now remove this element and return it:
  heap[first] = smallest->next;
  smallest->next = nullptr;
  nelems--;
 
  n_in_heap[first]--;
  if (n_in_heap[top_of_heap] == 0)
    for (i = top_of_heap - 1; i >= 0; i--)
      if (n_in_heap[i] > 0)
        {
          top_of_heap = i;
          break;
        }
 
  return smallest;
}

References compare(), heap, n_in_heap, nelems, s_pair::next, and top_of_heap.