Give an example of a graph G with at least 10 vertices such that the greedy 2-approximation algorithm for Vertex-Cover given below is guaranteed to produce a suboptimal vertex cover.
Give an example of a graph G with at least 10 vertices such that the greedy...
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...
Consider a tree with 13 nodes: the root has 4 children and each of these children has 2 children. Consider the following greedy algorithm for vertex cover: add the node with the highest degree to the vertex cover, remove all edges incident to this node, and repeat until there are no edges left. What approximation ratio is achieved by the algorithm on this graph? Give your answer to 2 decimal places. Can someone help me with this question? Thanks.
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...
Consider the following weighted, directed graph G. There are 7 vertices and 10 edges. The edge list E is as follows:The Bellman-Ford algorithm makes |V|-1 = 7-1 = 6 passes through the edge list E. Each pass relaxes the edges in the order they appear in the edge list. As with Dijkstra's algorithm, we record the current best known cost D[V] to reach each vertex V from the start vertex S. Initially D[A]=0 and D[V]=+oo for all the other vertices...
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...
Let G (V, E) be a directed graph with n vertices and m edges. It is known that in dfsTrace of G the function dfs is called n times, once for each vertex It is also seen that dfs contains a loop whose body gets executed while visiting v once for each vertex w adjacent to v; that is the body gets executed once for each edge (v, w). In the worst case there are n adjacent vertices. What do...
Consider a directed acyclic graph G = (V, E) without edge lengths and a start vertex s E V. (Recall, the length of a path in an graph without edge lengths is given by the number of edges on that path). Someone claims that the following greedy algorithm will always find longest path in the graph G starting from s. path = [8] Ucurrent = s topologically sort the vertices V of G. forall v EV in topological order do...
Definition: Given a Graph \(\mathrm{G}=(\mathrm{V}, \mathrm{E})\), define the complement graph of \(\mathrm{G}, \overline{\boldsymbol{G}}\), to be \(\bar{G}=(\mathrm{V}, E)\) where \(E\) is the complement set of edges. That is \((\mathrm{v}, \mathrm{w})\) is in \(E\) if and only if \((\mathrm{v}, \mathrm{w}) \notin \mathrm{E}\) Theorem: Given \(\mathrm{G}\), the complement graph of \(\mathrm{G}, \bar{G}\) can be constructed in polynomial time. Proof: To construct \(G\), construct a copy of \(\mathrm{V}\) (linear time) and then construct \(E\) by a) constructing all possible edges of between vertices in...
5. Here are the vertices and edges of directed graph G: V= {2.6.c.de.f} E= {ab, ac, af ca. bc. be.bf. cd, ce, de, df). Weights: w(ab) = 2 w(ac) = 5, w(af) = 10, w(ca) = 2. w(be) = 2. w(be) = 10, w(bf) = 11. w(cd)= 9. w(ce) = 7. w(de) = 2. w(df) = 2. a. Draw the Graph. This is a directed, weighted graph so you need to include arrows and weights. You can insert a pic...
Let G -(V, E) be a graph. The complementary graph G of G has vertex set V. Two vertices are adjacent in G if and only if they are not adjacent in G. (a) For each of the following graphs, describe its complementary graph: (i) Km,.ni (i) W Are the resulting graphs connected? Justify your answers. (b) Describe the graph GUG. (c) If G is a simple graph with 15 edges and G has 13 edges, how many vertices does...