Conferences in Research and Practice in Information Technology
  

Online Version - Last Updated - 20 Jan 2012

 

 
Home
 

 
Procedures and Resources for Authors

 
Information and Resources for Volume Editors
 

 
Orders and Subscriptions
 

 
Published Articles

 
Upcoming Volumes
 

 
Contact Us
 

 
Useful External Links
 

 
CRPIT Site Search
 
    

Counting paths in planar width 2 branching programs

Mahajan, M., Saurabh, N. and Sreenivasaiah, K.

    We revisit the problem of counting paths in width-2 planar branching programs. We show that this is hard for Boolean NC1 under ACC0 [5] reductions, completing a proof strategy outlined in [3]. On the other hand, for several restricted instances of width-2 planar branching programs, we show that the counting problem is TC0-complete. We also show that non-planar width-2 programs can be planarized in AC0[2]. Using the equivalence of planar width-2 programs with the reduced-form representation of positive rationals, we show that the evaluation problem for this representation in the Stern-Brocot tree is also NC1 hard. In contrast, the evaluation problem in the continued fraction representation is in TC0.
Cite as: Mahajan, M., Saurabh, N. and Sreenivasaiah, K. (2012). Counting paths in planar width 2 branching programs. In Proc. Computing: The Australasian Theory Symposium (CATS 2012) Melbourne, Australia. CRPIT, 128. Mestre, J. Eds., ACS. 59-68
pdf (from crpit.com) pdf (local if available) BibTeX EndNote GS