پاورپوینت مسائلی مشهور در گراف (pptx) 15 اسلاید
دسته بندی : پاورپوینت
نوع فایل : PowerPoint (.pptx) ( قابل ویرایش و آماده پرینت )
تعداد اسلاید: 15 اسلاید
قسمتی از متن PowerPoint (.pptx) :
به نام خداعنوان: مسائلی مشهور در گراف
Vertex cover Min Vertex cover 𝛽(G)
Matching
Maximum matching
⍺’(G)
Independent set
Maximum independent set
⍺(G)
Edge cover Maximum edge cover 𝛽’(G)
Kőnig's theorem
𝛽(G) = |V| -⍺(G)
⍺’(G)<= 𝛽(G)
⍺(G) = 𝛽’(G)
In bipartite graphs
Dénes Kőnig (1931)
Augmenting path
Berge's lemma
States that a matching M in a graph G is maximum if and only if there is no augmenting path with M.
Edmonds' algorithm
Jack Edmonds (1967)
O(EV)
O(E log V) Tarjan
f
f
f
Hall’s theorem
Gives a necessary and sufficient condition for being able to find matching in bipartite graphs that can cover at least one side of vertices.
For each subset of X like S the N(S) is subset of Y that are all of the neighbors of S . We have |N(s)|>=|S|.
The matching (blue edges) cover X
* proof by induction or Berge lemma