Let G = (V, E) denote an weighted undirected graph, in which every edge has unit weight, and let T = (V, E') denote the minimum spanning tree of G. Prove formally that the graph G need not have a unique tree T

Let G = (V, E) be a connected graph that has two distinct spanning trees. Prove that |E| > |V] – 1.

Let G = (V, E) be an undirected graph with at least two distinct vertices a, b ∈ V . Prove that we can assign a direction to each edge e ∈ E as to form a directed acyclic graph G′ where a is a source and b is a sink.

Square graph. The square of a directed graph G = (V,E) is the graph G^2 =(V,E^2)suchthat(u,w)∈E^2 if and only iff or some v∈V both(u,v)∈E and (v, w) ∈ E; that is, there is a path of exactly two edges. (i) Suppose that G is represented by an adjacency list. Describe an efficient algorithm for computing G^2 from G. (ii) Suppose that G is represented by an adjacency matrix. Describe an efficient algorithm for computing G^2 from G.

Consider a graph G that is comprised only of non-negative weight edges such that (u, v) € E, w(u, w) > 0. Is it possible for Bellman-Ford and Dijkstra's algorithm to produce different shortest path trees despite always producing the same shortest-path weights? Justify your answer.

Let G = (V,E) be a simple graph which is weighted, undirected, and connected. Sup- pose G contains a unique edge having the largest weight. Let emax be this edge. Suppose removing emax in G does not disconnect G. Prove that any minimum spanning tree of G must not contain the edge emax. Hint: Prove by contradiction. (Consider on the contrary that the MST contains emax. Think in this way: Can we replace this edge by some other edge to reduce the total weight?)

Show that if all edges of a graph G have pairwise distinct weights, then thereis exactly one MST for G.

Let Tsp be the tree of shortest paths of the below graph (G1) starting from vertex A and let TMST be a minimum spanning tree of (G1). Circle the only assertion that is FALSE 24 18. A 14 19 30 15 20 16 Both Tsp and TMST Contain the two edges of weight 6 Tsp and TMST have the same number of edges O Tsp and TMST have six edges in common The shortest path between A and H uses exactly 4 edges