A bipartite graph is drawn on a channel if the vertices of one partite set are...

A bipartite graph is drawn on a channel if the vertices of one partite set are placed on one line in the plane (in some order) and the vertices of the other partite set are placed on a line parallel to it and the edges are drawn as straight-line segments between them. Prove that a connected graph G can be drawn on a channel without edge crossings if and only if G is a caterpillar. (***Please do on paper)

Expert Solution

Colby Messinger answered 2 years ago

Let G be a bipartite graph with 107 left vertices and 20 right vertices. Two vertices...

Let G be a bipartite graph with 107 left vertices and 20 right vertices. Two vertices u, v are called twins if the set of neighbors of u equals the set of neighbors of v (triplets, quadruplets etc are defined similarly). Show that G has twins. Bonus: Show that G has triplets. What about quadruplets, etc.?

2. Let G be a bipartite graph with 10^7 left vertices and 20 right vertices. Two...

2. Let G be a bipartite graph with 10^7 left vertices and 20 right vertices. Two vertices u, v are called twins if the set of neighbors of u equals the set of neighbors of v (triplets, quadruplets etc are defined similarly). Show that G has twins. Show that G has triplets. What about quadruplets, etc.? 3. Show that there exists a bipartite graph with 10^5 left vertices and 20 right vertices without any twins. 4. Show that any graph...

Problem 8. A bipartite graph G = (V,E) is a graph whose vertices can be partitioned...

Problem 8. A bipartite graph G = (V,E) is a graph whose vertices can be partitioned into two (disjoint) sets V1 and V2, such that every edge joins a vertex in V1 with a vertex in V2. This means no edges are within V1 or V2 (or symbolically: ∀u, v ∈ V1, {u,v} ∉ E and ∀u,v ∈ V2, {u,v} ∉ E). 8(a) Show that the complete graph K2 is a bipartite graph. 8(b) Prove that no complete graph Kn,...

Question 2: A bipartite graph with 2n vertices (namely |V1| = |V2| = n) is d-regular...

Question 2: A bipartite graph with 2n vertices (namely |V1| = |V2| = n) is d-regular if and only if the degree of every vertex in V1 ∪ V2 is exactly d. Show that a d-regular bipartite graph always has a perfect matching (a matching of size n that includes all vertices). ***Remarks: All the graphs here are without self loops and parallel or anti-parallel edges. A network is a directed graph with source s and sink t and capacity...

Network Structures Consider the set-up for the bipartite graph auction, with an equal number of buyers...

Network Structures Consider the set-up for the bipartite graph auction, with an equal number of buyers and sellers, and with each buyer having a valuation for the object being sold by each seller. Suppose that we have an instance of this problem in which there is a particular seller i who is the favorite: every buyer j has a strictly higher valuation for seller i’s object than for the object being sold by any other seller k. (In notation, we...

let G be a simple graph. show that the relation R on the set of vertices...

let G be a simple graph. show that the relation R on the set of vertices of G such that URV if and only if there is an edge associated with (u,v) is a symmetric irreflexive relation on G

Null graph,Nn, n=1,2,3,4...，the graph with n vertices and no edges. (N4=4 vertices with no edges) 4...

Null graph,Nn, n=1,2,3,4...，the graph with n vertices and no edges. (N4=4 vertices with no edges) 4 a) find a graph with 8 vertices with no 3-cycles and no induced sub graph isomorphic to N4 b)prove that every simple graph with 9 vertices with no 3-cycles has an induced sub graph isomorphic to N4

Let G(V, E,w) be a weighted undirected graph, where V is the set of vertices, E...

Let G(V, E,w) be a weighted undirected graph, where V is the set of vertices, E is the set of edges, and w : E → R + is the weight of the edges (R + is the set of real positive numbers). Suppose T(G) is the set of all minimum spanning trees of G and is non-empty. If we know that the weight function w is a injection, i.e., no two edges in G have the same weight, then:...

An m × n grid graph has m rows of n vertices with vertices closest to...

An m × n grid graph has m rows of n vertices with vertices closest to each other connected by an edge. Find the greatest length of any path in such a graph, and provide a brief explanation as to why it is maximum. You can assume m, n ≥ 2. Please provide an explanation without using Hamilton Graph Theory.

3. What are the necessary and sufficient conditions for a bipartite graph to have a perfect...

3. What are the necessary and sufficient conditions for a bipartite graph to have a perfect matching? Justify your answer. 4. Illustrate Lemma 3.1.21 using the Peterson graph.

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