4. (15 points) The following diagram shows a branch-and-bound tree search for an integer programming maximization proble
Posted: Tue May 10, 2022 7:07 pm
4. (15 points) The following diagram shows a branch-and-bound tree search for an integer programming maximization problem. Each node has a number in parenthesis representing the search order and a value Z indicating the optimal LP relaxation value in that node. Assume that only nodes 5 and 6 yield integer solutions (i.e., their optimal LP relaxation solution turned out to be an integer solution) (1). 2-64 (2), Z = 58 (3), Z- 61 (4), Z-58.5 (5), Z-55 (6), Z = 56 (7),Z = 57
(b) Now consider that we branch on node 2 and create two new nodes: 8 and 9. Node 9 is infeasible and node 8 has Z = 56.5. What can you say about the optimal solution of the problem? If you cannot conclude that the optimal solution has been found, which node should we explore next, why?
(b) Now consider that we branch on node 2 and create two new nodes: 8 and 9. Node 9 is infeasible and node 8 has Z = 56.5. What can you say about the optimal solution of the problem? If you cannot conclude that the optimal solution has been found, which node should we explore next, why?