MATP6620 / ISYE6760 Combinatorial Optimization and Integer Programming
Homework 7.

Due: Tuesday, May 10, 2011.
Penalty for late homeworks: 10% for each day or part of a day.

  1. Define a greedy algorithm for the node packing problem. How does your algorithm do on the instance given in Figure 9.1 on page 343 of the text?
  2. Describe a tabu search algorithm for node packing. Be sure to define your valid solutions, your neighbourhoods, and what you would do with violated constraints. Run your algorithm on the instance given in Figure 9.1 on page 343 of the text, starting from the solution you found in Question 1 until the algorithm finds two more local minima.
  3. Reformulate the following binary polynomial problem as an equivalent binary linear program, and solve it (using AMPL or otherwise):
    max        6x31 + 5x22 + 5x23 + 4x34 + 2x1x32 + 3x1x4 + 4x2x3 + 4x2x4
subject to             x1x3 + x22x4 + x1x2x4 ≤   1
           3x2x3x4 + 2x21x3 + 5x1x3x54 + 4x2 ≤ 6
                     5x1 + 4x2 + 6x3 + 4x4 ≤   14
                                        x  ∈   IB4

    John Mitchell
    Amos Eaton 325
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    mitchj at rpi dot edu
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