Abstract
We establish non-trivial lower bounds for several prefix problems in the CRCW PRAM model. The chaining problem is, given a binary input, for each 1 in the input, to find the index of the nearest 1 to its left. Our main result is that for an input of n bits, solving the chaining problem using O ( n ) processors requires inverse-Ackerman time. This matches the previously known upper bound. We also give a reduction to show that the same lower bound applies to a parenthesis matching problem, again matching the previously known upper bound. We also give reductions to show that similar lower bounds hold for the prefix maxima and the range maxima problem.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
