(b) To what general type of problems can the greedy method be applied?
(c) Describe the minimum cost spanning tree problem for weighted graphs.
(d) Give a greedy method for solving this problem.
(b) What does it mean to say that a problem is "NP"?
The "acyclic" problem is to determine whether a directed graph is cycle-free.
(c) Explain why the acyclic problem for graphs is (or is not) NP
(d) Explain why the acyclic problem for graphs is (or is not) NP hard