(28) A unicycle is a simple graph that contains exactly one cycle. Let un be the number of unicyc...
Problem 12.29. A basic example of a simple graph with chromatic number n is the complete graph on n vertices, that is x(Kn) n. This implies that any graph with Kn as a subgraph must have chromatic number at least n. It's a common misconception to think that, conversely, graphs with high chromatic number must contain a large complete sub- graph. In this problem we exhibit a simple example countering this misconception, namely a graph with chromatic number four that...
5. Let G is a simple planar graph containing no triangles. (i) Using Euler's formula, show that G contains a vertex of degree at most 3. (ii) Use induction to deduce that G is 4-colorable-(v).
5. Let G is a simple planar graph containing no triangles. (i) Using Euler's formula, show that G contains a vertex of degree at most 3. (ii) Use induction to deduce that G is 4-colorable-(v).
4. Let G be a simple graph having at least one edge, and let L(G) be its line graph. (a) Show that x'(G) = x(L(G)). (b) Assume that the highest vertex degree in G is 3. Using the above, show Vizing's Theorem for G. You may use any theorem from class involving the chromatic number, but no theorem involving the chro- matic index.
Given an undirected connected graph so that every edge belongs to at least one simple cycle (a cycle is simple if be vertex appears more than once). Show that we can give a direction to every edge so that the graph will be strongly connected. Please write time complexity.
Let language L consist of simple, undirected graphs that contain at least one cycle. Prove that L ∈ NP.
Question 1: Given an undirected connected graph so that every edge belongs to at least one simple cycle (a cycle is simple if be vertex appears more than once). Show that we can give a direction to every edge so that the graph will be strongly connected. Question 2: Given a graph G(V, E) a set I is an independent set if for every uv el, u #v, uv & E. A Matching is a collection of edges {ei} so...
2. (a) Let G be a connected non-complete graph with order n 2 3 and diameter d. Prove that the connectivity K(G) of G satisfies d-1 (b) A connected graph is called unicyclic if it contains exactly one cycle. Prove that the edge-connectivity of any unicyclic graph is at most 2.
2. (a) Let G be a connected non-complete graph with order n 2 3 and diameter d. Prove that the connectivity K(G) of G satisfies d-1 (b) A connected...
Sketch any graph with five nodes that contains exactly two triangles. Let M be the adjacency matrix for your graph. Write down the matrix M3 . How could the matrix M3 be used to identify that the graph contains exactly two triangles?
A computer system uses passwords that contain exactly 3 characters, and each character is one of the 26 lowercase letters (a-z) or 26 uppercase letters (A-Z) or 10 integers (0-9). Let Ω denote the set of all possible passwords, and let and denote the events that consist of passwords with only letters or only integers, respectively Suppose that all passwords in 2 are equally likely. Determine the following probabilities. Round your answers to three decimal places (e.g. 98.765). (c) The...
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...