Generator-Preserving contractions and a Min-Max result on the graphs of planar polyominoes
نویسندگان
چکیده
In this paper, we deal with the convex generators 1 of a graph G = (V(G),E(G)). A convex generator being a minimal set whose convex hull is V(G), we show that it is included in the "boundary" of G. Then we show that the "boundary" of a polymino's graph, or more precisely the seaweed's "boundary", enjoys some nice properties which permit us to prove that for such a graph G, the minimal size of a convex generator is equal to the maximal number of hanging vertices of a tree T, obtained from G by a sequence of generator-preserving contractions.
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ورودعنوان ژورنال:
- Ars Comb.
دوره 55 شماره
صفحات -
تاریخ انتشار 2000