Fix non-trivial presolve not reporting Optimality #26
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aliceb-nv
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We need to add the bound here too: |
…ed a separate test for trivial presolve
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chris-maes
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chris-maes
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This looks good to me. But I'm not an expert on this code. You might want @akifcorduk to get eyes on this as well.
Thanks for taking the initiative to fix this bug Alice. Your work is much appreciated!
| CUOPT_LOG_INFO("Problem fully reduced at trivial presolve"); | ||
| solution_t<i_t, f_t> sol(*context.problem_ptr); | ||
| sol.set_problem_fully_reduced(); | ||
| context.problem_ptr->post_process_solution(sol); |
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Dumb question: is this where the solution is populated? Where does presolve store the information about the solution when the problem is fully reduced in presolve?
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In the case of fully presolved problems the solution is populated by post_process_solution() (which tracks the transformations made by presolve) and additional solving stats information is added when get_solution() is called to return the final mip_solution_t : https://github.com/NVIDIA/cuopt/blob/branch-25.05/cpp/src/mip/solution/solution.cu#L560-L606
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| // gets the is_feasible | ||
| bool get_feasible(); | ||
| // gets the is_problem_infeasible | ||
| bool get_problem_infeasible(); |
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Why do we remove the infeasible options? The problem can be infeasible right?
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I decided to cover both the case of infeasibility and optimality after presolve with set_problem_fully_reduced. get_solution() then determines, based on the status of the solution after post_process, which status to return (Optimal or Infeasible)
This ended up making the code more concise so that's why I went with this :)
| CUOPT_LOG_INFO("Problem proven infeasible in presolve"); | ||
| solution_t<i_t, f_t> sol(*context.problem_ptr); | ||
| sol.set_problem_infeasible(); | ||
| sol.set_problem_fully_reduced(); |
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If we decide to keep infeasible, here it makes more sense to keep set_problem_infeasible
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/merge |
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The non-trivial presolve did not report optimality if the problem was fully reduced. Fixed by this PR
Closes https://github.com/rapidsai/cuopt/issues/2507