Fix false optimality declaration in the determinsitic mode

[aliceb-nv]

When the solve is interrupted due to a time limit in the deterministic B&B code, remaining nodes abort their solve and return status PENDING which wasn't properly handled by the deterministic codepath, dropping all such nodes from the tree and causing the dual bound to become +inf. If a primal solution was found, it would thus immediately be declared (incorrectly) as optimal.

This PR fixes this issue.

Description

Issue

Checklist

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• Testing
  • New or existing tests cover these changes
  • Added tests
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• Documentation
  • The documentation is up to date with these changes
  • Added new documentation
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[aliceb-nv]

/ok to test d8ed289

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ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between d8ed289 and c950f30.

📒 Files selected for processing (1)

• cpp/src/branch_and_bound/branch_and_bound.cpp

🚧 Files skipped from review as they are similar to previous changes (1)

• cpp/src/branch_and_bound/branch_and_bound.cpp

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📝 Walkthrough

Walkthrough

The status declaration in run_deterministic_bfs_loop is aligned with adjacent declarations. Behavior is unchanged.

Changes

Deterministic BFS execution

Layer / File(s)	Summary
Status declaration alignment cpp/src/branch_and_bound/branch_and_bound.cpp	The declaration alignment in run_deterministic_bfs_loop is adjusted without changing behavior.

Priority: ➖ Normal

Estimated code review effort: 1 (Trivial) | ~2 minutes

Change: Bug fix

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the main change: preventing false optimality declarations in deterministic mode. It contains a minor spelling error in "determinsitic," but the meaning remains clear.
Description check	✅ Passed	The description directly explains the deterministic branch-and-bound issue, including the handling of PENDING nodes, the incorrect dual bound, and the resulting false optimality declaration.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[Kh4ster]

Great minimal fix, thanks @aliceb-nv !

[aliceb-nv]

/ok to test c950f30

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CI Test Summary

✅ All 18 test job(s) passed. (3 skipped)