Test TreeSearch

[guimarqu]

No description provided.

[guimarqu]

1- About responsibilities to manage nodes of the tree search algorithm (done in #994)

• explore has the responsibility to stop the exploration when there is no untreated nodes leaving.

• TreeSearch.stop (meta condition) checks only "meta" conditions (stop the algorithm when the number of nodes explodes).

• The divide algorithm creates the nodes.

• Implementation of the ColunaSearchSpace interface has the responsibility to not call Divide if the node is pruned.

2 - About the conquer output

The conquer algorithm must return the following statuses:

• infeasible
• optimal if the subproblem at the node has been "fully" optimized
• other limit, otherwise

3 - Leaves data (done in #995)

To determine the result status of the branch and bound algorithm, we'll need to store the following data for all leaves:

• status (infeasible, optimal, other limit)
• local dual bound

4- Global dual bound (done in #997)

min(local dual bound of leaves, local dual bound of parent of untreated nodes)

5- Tree search output (done in #997)

When the exploration has finished, tree search output checks whether we found the optimal solution, the problem is infeasible or a limit has been reached.

• infeasible: all leaves infeasible [extra optional check : length(ip_primal_sols) == 0 (to make sure there is no bug in the children generation) - show warning if false]
• optimal : gap closed [extra optional check: length(ip_primal_sols) > 0 - show warning if false]
• other limit; otherwise

[guimarqu]

ping @najaverzat

[guimarqu]

I feel like this issue is now completed by all the work done during the last two weeks.