B-1 Graph coloring Given an undirected graph G (V. E), a k-coloring of G is a function c : V → {0, 1, . . . ,k-1} such that c(u)≠c(v) for every edge (u, v) ∈ E. In other words, the numbers 0.1,... k-1 represent the k colors, and adjacent vertices different colors. must havec. Let d be the maximum degree of any vertex in a graph G. Prove that we can color G with d +1 colors.
graph G, let Bi(G) max{IS|: SC V(G) and Vu, v E S, d(u, v) 2 i}, 10. (7 points) Given a where d(u, v) is the length of a shortest path between u and v. (a) (0.5 point) What is B1(G)? (b) (1.5 points) Let Pn be the path with n vertices. What is B;(Pn)? (c) (2 points) Show that if G is an n-vertex 3-regular graph, then B2(G) < . Further- more, find a 3-regular graph H such that...
Question 5: [10pt total] Let G be the following graph: True for False: Which of the following statements are true about G? 5)a) (1pt] G is a directed graph: 5)f) [1pt] G is bipartite: 5)b) [1pt] G is a weighted graph: 5)g) (1pt] G has a leaf vertex: ......... 5)c) [1pt] G is a multi-graph: 5)h) [1pt] G is planar: 5)d) [1pt] G is a loop graph: 5)i) [1pt] G is Eulerian: 5)) (1pt] G is a complete graph: 5)j)...
G H H26 Let r be the number of regions in a plane diagram of a disconnected planar graph G Suppose that G has k components. (a) Find the value of v-e+r in terms of k if G is a forest. (b) Find v - e + r any planar graph with k components. (See the proof of Euler's Formula if necessary.)
G H H26 Let r be the number of regions in a plane diagram of a disconnected planar...
Question 5 12 pts Claim: The graph pictured below has an Hamiltonian circuit. O True O False Question 6 12 pts Claim: There exists a graph with 4 vertices with degrees 1, 1, 3, 3. O True O False Question 7 12 pts Claim: The graph pictured below has an Euler circuit. O True O False Question 8 12 pts Claim: The graph pictured below has an Euler circuit. O True O False
Question 1# (a) Let G be a connected graph and C a non-trivial circuit in G. Prove directly that if an edge e fa, b is removed from C then the subgraph S C G that remains is still connected. "Directly' means using only the definitions of the concepts involved, in this case connected' and 'circuit'. Hint: If z and y are vertices of G connected by path that includes e, is there an alternative path connecting x to y...
Problem 2.13 - page 31. Let G be an n-vertex graph such that for any non-adjacent vertices U, V EV(G), d(u) + d(u) > n. Prove that G is Hamiltonian
2) Let G ME) be an undirected Graph. A node cover of G is a subset U of the vertex set V such that every edge in E is incident to at least one vertex in U. A minimum node cover MNC) is one with the lowest number of vertices. For example {1,3,5,6is a node cover for the following graph, but 2,3,5} is a min node cover Consider the following Greedy algorithm for this problem: Algorithm NodeCover (V,E) Uempty While...
Let G = (V;E) be an undirected and unweighted graph. Let S be a subset of the vertices. The graph induced on S, denoted G[S] is a graph that has vertex set S and an edge between two vertices u, v that is an element of S provided that {u,v} is an edge of G. A subset K of V is called a killer set of G if the deletion of K kills all the edges of G, that is...
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3. (8 pts) A graph is called planar if it can be drawn in the plane without any edges crossing. The Euler's formula states that v - etr = 2, where v, e, and r are the numbers of vertices, edges, and regions in a planar graph, respectively. For the following problems, let G be a planar simple graph with 8 vertices. (a) Find the maximum number of edges in G. (b) Find...