Pairing Heaps with Costless Meld

Improving the structure and analysis in \cite{elm0}, we give a variation of the pairing heaps that has amortized zero cost per meld (compared to an $O(\log \log{n})$ in \cite{elm0}) and the same amortized bounds for all other operations. More precisely, the new pairing heap requires: no cost per meld, O(1) per find-min and insert, $O(\log{n})$ per delete-min, and $O(\log\log{n})$ per decrease-key. These bounds are the best known for any self-adjusting heap, and match the lower bound proved by Fredman for a family of such heaps. Moreover, the changes we have done make our structure even simpler than that in \cite{elm0}.