main page — COMP 526 Efficient Algorithms
Unit 3: Efficient Sorting
This unit covers
- mergesort and quicksort
- counting sort
- parallel RAM model
- parallel prefix sums
- parallel mergesort and quicksort
Learning outcomes
- Know principles and implementation of mergesort.
- Know principles and implementation of quicksort.
- Know properties and performance characteristics of mergesort and quicksort.
- Know the comparison model and understand the corresponding lower bound.
- Understand counting sort and how it circumvents the comparison lower bound.
- Understand and use the parallel random-access-machine model in its different variants.
- Be able to analyze and compare simple shared-memory parallel algorithms by determining parallel time and work.
- Understand efficient parallel prefix sum algorithms.
- Be able to devise high-level description of parallel quicksort and mergesort methods.
Material
- slides
- lecture notes
- Video 3-1 (2021-02-24):
§3.0 Sorting introduction
- Video 3-2 (2021-02-24):
§3.1 Mergesort
- Video 3-3 (2021-02-24):
§3.2 Quicksort
- Video 3-4 (2021-03-02):
§3.3 Comparison-based lower bound
- Video 3-5 (2021-03-02):
§3.4 Integer sorting
- Video 3-6 (2021-03-02):
§3.5 Parallel computation, PRAM
- Video 3-7 (2021-03-03):
§3.6 Parallel primitives, prefix sum
- Video 3-8 (2021-03-03):
§3.7 Parallel sorting
Further reading and sources
More elementary sorting methods are described in detail in Algorithms 4th ed.
The presentation of parallel methods takes some inspiration from Uzi Vishkin’s class notes: