Parallel Computing: Lecture 22

Learning objectives

After this class, you should be able to:

1. Show the steps of the distributed termination detection algorithm discussed in class, and prove its correctness.
2. Explain the parallelization of branch and bound algorithms.
3. Given a combinatorial search problem, give a method for efficiently computing a bound on the optimal solution, and use this to draw the first few levels of the tree and show the order in which branch and bound algorithms will search this tree.
4. Given an algorithm that claims to detect termination, prove or disprove its correctness, and compare its advantages and disadvantages over the one discussed in class.
5. Given a parallelization of branch and bound algorithms, compare its advantages and disadvantages over the one discussed in class.

Reading assignment

1. Chapter 16, sections 16.5 - 16.6.
2. None.

Exercises and review questions

• Questions on current lecture's material
  1. Give a counterexample to show that algorithm B for termination detection (without the count field) is incorrect if messages are not instantaneous.
  2. Exercise 16.4.
  3. Exercise 16.5.

• Questions on next lecture's material
  1. None.