The topic of week 4’s lectures and assignment was Sort and Scan. These are slightly more complex due to the many-to-many, all-to-all communication patterns. Part 1 focused on Scan. Important properties of Scan, work complexity: O(n),  step complexity: O(log n). Variations on the Scan algorithm: Compact/Filter – Gathering a subset that meet a certain criteria (input, predicate, output). Ie only keep input elements where the predicate is true. Outputs can be dense.. Read More