Parallel Computing

I. [6] The Work-Time (W-T) presentation of EREW sequence reduction (Algorithm 2 in PRAM handout) has work complexity WW(nn) = Ο(nn) and step complexity SS(nn) = Ο(lgnn). Following the strategy of Brent’s theorem, the translation of this algorithm will yield a pp processor EREW PRAM program with running time TTCC(nn,pp) = Ο(nn pp ⁄ + lgnn) (a) Construct an alternate sequence reduction algorithm directly for the bare bones EREW PRAM with running time TTCC(nn,pp) = Ο(nn pp ⁄ + lg pp). (b) Explain why your solution to (a) cannot be expressed in the W-T model.