Some triply-logarithmic parallel algorithms

It is established that several natural problems have triply logarithmic, or even faster, optimal parallel algorithms. These problems include: merging two sorted lists, where the values are drawn from a large, but restricted, domain on a CREW PRAM; finding all prefix minima, where the values are drawn from a restricted domain; and top-bottom global routing around a rectangle, a well-investigated problem in VLSI routing for which only highly involved serial algorithms were known.<
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