6.889: Algorithms for Planar Graphs and Beyond (Fall 2011)

Erik Demaine, Shay Mozes, Christian Sommer, Siamak Tazari

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[+] Approximation schemes in planar graphs: Branchwidth and Baker's technique.

In this lecture we introduce two additional graph decompositions - carving decomposition and branch decomposition. We prove a theorem of Tamaki that roughly says that the branch-width of a planar graph is at most twice its radius. We use the radius bound on the width of a decomposition of planar graphs to devise a PTAS for minimum vertex cover. This PTAS is an example of a general technique due to Baker, which can be applied to many other problems.

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Lecture notes, page 1/12[previous page][next page][PDF]

Lecture notes, page 1/12[previous page][next page][PDF]

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