Fix #498: [Model] SequencingToMinimizeWeightedTardiness

[GiggleLiu]

Summary

Add the execution plan and implementation for SequencingToMinimizeWeightedTardiness.

Fixes #498

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.46%. Comparing base (fa40ce7) to head (819005f).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##             main     #672    +/-   ##
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  Coverage   97.45%   97.46%            
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  Files         351      353     +2     
  Lines       44931    45097   +166     
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+ Hits        43788    43954   +166     
  Misses       1143     1143            

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[Copilot]

Pull request overview

Adds a new NP-complete scheduling model, SequencingToMinimizeWeightedTardiness (1 || Σ w_j T_j), and integrates it across the crate (exports, schema/variants, examples, CLI creation support, tests, and documentation/paper).

Changes:

• Introduces SequencingToMinimizeWeightedTardiness model with Lehmer-code encoding, schema registration, and declared default variant complexity.
• Adds unit tests + example-db fixture entry for the new model.
• Extends pred create CLI support (flags, examples, tests) and regenerates docs JSON + paper section/bibliography.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/models/misc/sequencing_to_minimize_weighted_tardiness.rs	New problem model implementation + schema entry + variants + example-db spec + test wiring
src/models/misc/mod.rs	Registers and re-exports the new misc model; adds to example-db aggregation
src/models/mod.rs	Re-exports the new model at the top-level models module
src/lib.rs	Re-exports the new model in the public prelude
src/unit_tests/models/misc/sequencing_to_minimize_weighted_tardiness.rs	New model-focused unit tests (evaluation, invalid configs, solver, serialization)
src/unit_tests/trait_consistency.rs	Adds the new model to trait consistency checks
src/example_db/fixtures/examples.json	Adds a canonical example instance + sample/optimal configs
problemreductions-cli/src/commands/create.rs	Adds pred create SequencingToMinimizeWeightedTardiness parsing + example usage text
problemreductions-cli/src/cli.rs	Documents required flags for the new pred create problem type
problemreductions-cli/tests/cli_tests.rs	Adds CLI tests for successful creation, mismatch rejection, and help output
docs/src/reductions/problem_schemas.json	Adds generated schema entry for the new model
docs/src/reductions/reduction_graph.json	Adds generated graph node for the new model and reindexes affected edges
docs/paper/references.bib	Adds bibliography entries referenced by the new paper section
docs/paper/reductions.typ	Adds the paper definition + example/figure block for the new model

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[GiggleLiu]

Agentic Review Report

Structural Check

#	Check	Status
1	Model file exists at src/models/misc/sequencing_to_minimize_weighted_tardiness.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 with >= 3 test functions	PASS (10 tests)
8	Registered in misc/mod.rs	PASS
9	Re-exported in models/mod.rs	PASS
10	declare_variants! entry	PASS — default sat, complexity "factorial(num_tasks)"
11	CLI create support	PASS
12	Canonical model example registered	PASS
13	Paper display-name entry	PASS
14	Paper problem-def block	PASS

Build: make test PASS, make clippy PASS, make fmt-check PASS

Issue Compliance (Issue #498): 8/8 checks passed. Lehmer code encoding (vs raw position indices) is a justified deviation — standard in this codebase. Canonical example uses K=13 (uniquely satisfying) instead of issue's K=15 — beneficial tightening.

Semantic Review:

• evaluate(): Correct — decodes Lehmer code, computes per-job completion times and weighted tardiness with u128 overflow protection, returns total <= bound
• dims(): Correct — [n, n-1, ..., 2, 1] for Lehmer code domain
• Invalid inputs: Properly handled — bad digit or wrong-length config returns false
• Complexity string "factorial(num_tasks)": Appropriate for strongly NP-complete problem with no known sub-factorial exact algorithm

Whitelist deviation: cli.rs modified with a single help-text line (not a functional concern).

Result: 14/14 structural checks passed. 0 critical, 0 important issues.

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Quality Check

Design Principles:

• DRY (Minor, pre-existing): Lehmer decode logic duplicated across 4 scheduling models in src/models/misc/. The PR follows the existing pattern (and improves on it by extracting a named decode_schedule method). A shared utility would eliminate all 4 copies, but this is pre-existing technical debt.
• KISS: OK — clean decode_schedule / schedule_weighted_tardiness / total_weighted_tardiness decomposition
• HC/LC: OK — single-responsibility model file, well-scoped private helpers

HCI (CLI changed):

• Error messages: OK — actionable, include usage examples
• Discoverability: OK — --example and help text work
• Consistency (Minor): CLI flag --sizes maps to struct field lengths and mathematical concept "processing times." The reuse of --sizes from BinPacking is pragmatic but creates a vocabulary mismatch. A --task-lengths flag (already used by FlowShopScheduling) would be more consistent.

Test Quality:

• 10 test functions: creation/accessors, exact tardiness computation, evaluate yes/no, invalid Lehmer digits, wrong-length config, brute-force solver (sat/unsat), paper example uniqueness verification, serialization round-trip
• All tests are substantive with concrete value assertions
• Minor gap: All tests use the same 5-job instance (varying only the bound). A second structurally different instance would marginally improve confidence.

Issues:

#	Severity	Description
1	Minor	CLI --sizes vs struct lengths naming mismatch (create.rs:948)
2	Minor (pre-existing)	Lehmer decode duplicated in 4 scheduling models
3	Minor	All 10 unit tests use the same base instance

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Agentic Feature Tests

Test	Command	Status
1. pred list	pred list	PASS — appears in catalog with complexity O(factorial(num_tasks))
2. pred show	pred show SequencingToMinimizeWeightedTardiness	PASS — fields, description, complexity all correct
3. pred create --example	pred create --example SequencingToMinimizeWeightedTardiness	PASS — valid JSON, 5-job instance
4. pred solve	pred solve --solver brute-force <file>	PASS — solution [0,0,2,1,0], total weighted tardiness = 13
5. pred create (manual)	pred create SequencingToMinimizeWeightedTardiness --sizes ...	PARTIAL PASS

Issues:

#	Severity	Description
1	Important	Help text shows --lengths as parameter but only --sizes works. Running pred create SequencingToMinimizeWeightedTardiness displays contradictory output: Parameters section lists --lengths, Example section shows --sizes. Fix: add "lengths" => "sizes" mapping in cli_flag_name() at create.rs:217.
2	Suggestion	--sizes clap help text says "Item sizes for BinPacking" — now shared with 3 problems, should use generic description

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