The answer is no. To see why, let’s first articulate the question like so: Q: For a connected, undirected, weighted graph G = (V, E, w) with only nonnegative edge weights, does the predecessor subgraph produced by Dijkstra’s Algorithm form a minimum spanning tree of G? (Note that undirected graphs are a special class of … Read more
Prim’s algorithm constructs a minimum spanning tree for the graph, which is a tree that connects all nodes in the graph and has the least total cost among all trees that connect all the nodes. However, the length of a path between any two nodes in the MST might not be the shortest path between … Read more
The equivalent of a minimum spanning tree in a directed graph is called an optimum branching or a minimum-cost arborescence. The classical algorithm for solving this problem is the Chu-Liu/Edmonds algorithm. There have been several optimized implementations of this algorithm over the years using better data structures; the best one that I know of uses … Read more
Look at the MST example on Wikipedia for reference: A bottleneck in a spanning tree is a maximum-weight edge in that tree. There may be several bottlenecks (all of the same weight of course) in a spanning tree. In the Wikipedia MST there are two bottlenecks of weight 8. Now, take a minimum spanning tree … Read more
Yes, you are right. The concept of MST allows weights of an arbitrary sign. The two most popular algorithms for finding MST (Kruskal’s and Prim’s) work fine with negative edges. Actually, you can just add a big positive constant to all the edges of your graph, making all the edges positive. The MST (as a … Read more
Yes, it does. One method for computing the maximum weight spanning tree of a network G – due to Kruskal – can be summarized as follows. Sort the edges of G into decreasing order by weight. Let T be the set of edges comprising the maximum weight spanning tree. Set T = ∅. Add the … Read more
Prim’s algorithm constructs a minimum spanning tree for the graph, which is a tree that connects all nodes in the graph and has the least total cost among all trees that connect all the nodes. However, the length of a path between any two nodes in the MST might not be the shortest path between … Read more
Use Prim’s algorithm when you have a graph with lots of edges. For a graph with V vertices E edges, Kruskal’s algorithm runs in O(E log V) time and Prim’s algorithm can run in O(E + V log V) amortized time, if you use a Fibonacci Heap. Prim’s algorithm is significantly faster in the limit … Read more