Strict Fibonacci Heaps

Gerth Stølting Brodal, George Lagogiannis, and Robert E. Tarjan

In Proc. 44th Annual ACM Symposium on Theory of Computing, pages 1177-1184, 2012.


We present the first pointer-based heap implementation with time bounds matching those of Fibonacci heaps in the worst case. We support make-heap, insert, find-min, meld and decrease-key in worst-case O(1) time, and delete and delete-min in worst-case O(lg n) time, where n is the size of the heap. The data structure uses linear space.

A previous, very complicated, solution achieving the same time bounds in the RAM model made essential use of arrays and extensive use of redundant counter schemes to maintain balance. Our solution uses neither. Our key simplification is to discard the structure of the smaller heap when doing a meld. We use the pigeonhole principle in place of the redundant counter mechanism.

Copyright notice

Copyright © 2012 by the Association for Computer Machinery, Inc.

Online version

stoc12.pdf (166 Kb)




Video of conference talk available at the papers DOI (see "Source Materials")


stoc12.pdf (316 Kb), stoc12.pptx (233 Kb)

BIBTEX entry

  author = "Gerth St{\o}lting Brodal and George Lagogiannis and Robert E. Tarjan",
  booktitle = "Proc. 44th Annual ACM Symposium on Theory of Computing",
  doi = "10.1145/2213977.2214082",
  isbn = "978-1-4503-1245-5",
  pages = "1177-1184",
  title = "Strict Fibonacci Heaps",
  year = "2012"