Fix #410: [Model] MultipleCopyFileAllocation

[GiggleLiu]

Summary

Add the execution plan for the MultipleCopyFileAllocation model.

Fixes #410

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.47%. Comparing base (1bafa02) to head (25493a5).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #665      +/-   ##
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+ Coverage   97.46%   97.47%   +0.01%     
==========================================
  Files         353      355       +2     
  Lines       45097    45294     +197     
==========================================
+ Hits        43954    44151     +197     
  Misses       1143     1143              

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[GiggleLiu]

Implementation Summary

Changes

• Added the MultipleCopyFileAllocation satisfaction model, schema metadata, registry/prelude wiring, canonical example, and unit/trait-consistency coverage.
• Added pred create MultipleCopyFileAllocation support with --graph, --usage, --storage, and --bound, plus CLI coverage for happy-path output and length-mismatch failures.
• Added the paper problem-def entry and regenerated reduction exports for the new model.

Deviations from Plan

• None.

Open Questions

• None.

[Copilot]

Pull request overview

Adds first-class support for the MultipleCopyFileAllocation graph satisfaction model across the library, CLI, tests, and generated docs/fixtures (fixes #410).

Changes:

• Introduces MultipleCopyFileAllocation model implementation (schema registration, variants, example-db spec, and evaluation/cost logic).
• Adds CLI pred create MultipleCopyFileAllocation support (+ new flags --usage / --storage) and corresponding CLI tests.
• Updates example-db fixtures and generated docs JSON, plus adds unit tests and paper documentation section.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/models/graph/multiple_copy_file_allocation.rs	New model implementation, schema registration, variants, and example-db spec
src/models/graph/mod.rs	Registers the new model module, re-export, and example-db hook
src/models/mod.rs	Re-exports MultipleCopyFileAllocation from the graph module
src/lib.rs	Exposes MultipleCopyFileAllocation via the crate prelude
src/unit_tests/models/graph/multiple_copy_file_allocation.rs	New unit tests covering creation, cost/validity, solver behavior, and serde
src/unit_tests/trait_consistency.rs	Ensures the model satisfies basic Problem trait expectations
problemreductions-cli/src/cli.rs	Adds --usage and --storage flags and updates help listing
problemreductions-cli/src/commands/create.rs	Adds create match arm + parsing helper for MCFA vertex vectors
problemreductions-cli/tests/cli_tests.rs	Adds CLI tests for create flow + validation errors
src/example_db/fixtures/examples.json	Adds MCFA canonical example and updates regenerated fixtures
docs/src/reductions/problem_schemas.json	Generated schema entry for MCFA
docs/src/reductions/reduction_graph.json	Generated reduction graph node entry for MCFA (and re-indexing)
docs/paper/reductions.typ	Adds paper section + figure/example for MCFA

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[GiggleLiu]

Agentic Review Report

Structural Check

#	Check	Status
1	Model file exists (src/models/graph/multiple_copy_file_allocation.rs)	PASS
2	inventory::submit! present	PASS
3	#[derive(...Serialize, Deserialize)] on struct	PASS
4	Problem trait impl	PASS
5	SatisfactionProblem impl	PASS
6	#[cfg(test)] + #[path = "..."] test link	PASS
7	Test file exists	PASS
8	Test file has >= 3 test functions	PASS (9 tests)
9	Registered in graph/mod.rs	PASS
10	Re-exported in models/mod.rs	PASS
11	declare_variants! entry	PASS
12	CLI alias resolution	PASS
13	CLI create support	PASS
14	Canonical model example registered	PASS
15	Paper display-name entry	PASS
16	Paper problem-def block	PASS

Build: make test PASS, make clippy PASS

Issue compliance: 8/8 checks passed. Problem name, mathematical definition, satisfaction type, configuration space, feasibility checks, and objective function all match issue #410.

Whitelist: FAIL — expected for model PRs needing new CLI flags. The solver-default refactor (dispatch.rs, solve.rs, inspect.rs, mcp/tools.rs, main.rs) is a bundled cross-cutting change directly motivated by the new model's lack of ILP reachability. Acceptable to merge as-is.

Semantic correctness:

• evaluate() correctly computes total cost = storage cost + usage-weighted BFS distances, compared against bound K
• Multi-source BFS is standard textbook approach, correctly handles multiple sources, unreachable vertices, and disconnected graphs
• Edge cases covered: empty V', non-binary configs, disconnected components, cost exactly above bound

Issues:

• [Suggestion] Missing positivity validation in constructor — usage and storage values should be strictly positive per the mathematical definition (Z+). Compare with MinimumSumMulticenter::new() which validates k > 0.
• [Important] Bundled solver-default refactor — significant CLI behavior change (dynamic solver selection based on ILP reachability) is bundled alongside the model. Well-implemented and well-motivated, but represents scope expansion beyond a pure model PR.

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Quality Check

Design Principles:

• DRY: OK for the model itself. Pre-existing solver resolution duplication between solve.rs and mcp/tools.rs is extended but not introduced by this PR.
• KISS: OK — clean BFS implementation, well-factored helpers (selected_vertices, shortest_distances, total_cost).
• HC/LC: OK — model struct, trait impl, and CLI wiring are well-separated.

HCI (CLI/MCP):

• Error messages are actionable with full usage hints
• pred create MultipleCopyFileAllocation without flags shows help with required parameters
• Flag naming (--graph, --usage, --storage, --bound) follows established conventions
• Solver auto-selection (ILP when reachable, brute-force otherwise) is a good UX improvement

Test Quality:

• 9 unit tests with concrete value assertions (not just type/shape checks)
• Instance diversity: cycle, path, heterogeneous weights, disconnected graph, yes/no instances
• Adversarial cases: empty config, non-binary values, all-zero config, unreachable components, cost exactly above bound
• Solver test validates both YES and NO instances
• Brute-force exhaustiveness: find_all_satisfying asserts exact count (36 configurations)
• Round-trip serialization test
• 7 CLI integration tests covering creation, inspection, error cases, and solver selection

Issues:

• [Important] Complexity string "2^num_vertices" — this is the naive brute-force bound. Per project guidelines, should verify whether a better exact algorithm exists in the literature.
• [Important] Test helper cycle_no_instance is misleadingly named — the graph is a path (6 vertices, 5 edges, missing edge 5-0), not a cycle. Should be path_no_instance.
• [Minor] Paper figure uses hardcoded vertex positions instead of computed circular layout.

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Agentic Feature Tests

#	Test	Command	Status
1	Catalog listing	pred list	PASSED
2	Detail display	pred show MultipleCopyFileAllocation	PASSED
3	Example creation	pred create --example MultipleCopyFileAllocation	PASSED
4	Brute-force solve	pred solve <instance>	PASSED
5	Manual creation	pred create MultipleCopyFileAllocation --graph ...	PASSED
6	Unit tests (9/9)	cargo test multiple_copy_file_allocation	PASSED
7	Full regression (2080/2080)	cargo test --lib	PASSED
8	Example-DB integration (3/3)	cargo test example_db	PASSED

Confirmed bugs: 0

All CLI features work correctly. Solutions were manually verified against the mathematical definition. Edge cases (unreachable vertices, no-solution instances, invalid configs) handled properly. No regressions detected.

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Generated by review-pipeline

[isPANN]

Please kindly check the following items (PR #665):

• Paper (PDF): check definition, proof sketch, and example figure
• CLI demo (build from source: cargo install --path problemreductions-cli):

  pred show MultipleCopyFileAllocation
  pred create --example MultipleCopyFileAllocation -o instance.json
  pred solve instance.json --solver brute-force

• Implementation (Optional): spot-check the source files changed in this PR for correctness