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CSC 373H / L0101        Lecture Summary for Week 11             Winter 2005
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Approximation algorithms
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Vertex Cover:

  - Repeatedly pick an edge and put both endpoints in C, then remove all
    edges incident on the two endpoints, until no edge remains.
    |C| <= 2 * OPT (size of smallest cover)
    because all covers include at least one endpoint from every edge in C
    so in particular, OPT >= |C|/2.

  - Repeatedly pick a vertex of largest degree and put it in C, removing
    all edges incident on that vertex, until no edge remains.
    There are inputs where |C| > 2 * OPT, unlike previous algorithm.

Load Balancing:  See section 11.1 in text.