Fix #443: Add RectilinearPictureCompression model by GiggleLiu · Pull Request #677 · CodingThrust/problem-reductions

GiggleLiu · 2026-03-16T15:58:01Z

Summary

Add the RectilinearPictureCompression satisfaction problem model — a classical NP-complete problem (Garey & Johnson A4 SR25) asking whether a binary matrix can be exactly covered by K or fewer axis-aligned all-1 rectangles.

Fixes #443

codecov · 2026-03-16T16:00:39Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.32%. Comparing base (ed1b160) to head (37d7592).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##             main     #677    +/-   ##
========================================
  Coverage   97.31%   97.32%            
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  Files         324      327     +3     
  Lines       41853    42170   +317     
========================================
+ Hits        40731    41042   +311     
- Misses       1122     1128     +6

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Implement the Rectilinear Picture Compression problem: given an m x n binary matrix M and bound K, determine if at most K axis-aligned all-1 rectangles can cover precisely the 1-entries of M. Includes model file, unit tests, CLI create support, canonical example, trait consistency check, and regenerated fixtures. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…(), add solution count assertion

GiggleLiu · 2026-03-16T16:34:40Z

Implementation Summary

Changes

src/models/misc/rectilinear_picture_compression.rs — New satisfaction problem model (binary matrix + bound K, maximal all-1 rectangle enumeration, precomputed candidate cache)
src/unit_tests/models/misc/rectilinear_picture_compression.rs — 21 unit tests (construction, evaluation, solver, serialization, edge cases, panic tests)
src/models/misc/mod.rs, src/models/mod.rs — Module registration and re-export
problemreductions-cli/src/commands/create.rs, problemreductions-cli/src/cli.rs — CLI pred create RectilinearPictureCompression --matrix --k support
src/unit_tests/trait_consistency.rs — Trait consistency check
src/example_db/ — Canonical model example (4×4 two-block matrix)
docs/paper/reductions.typ — Problem definition, background, CeTZ example diagram

Deviations from Plan

Maximal rectangles are precomputed in the constructor and cached (review fix: avoids redundant recomputation in dims() and evaluate())
Custom Deserialize implementation to recompute cache on deserialization
matrix() returns &[Vec<bool>] instead of &Vec<Vec<bool>> (idiomatic Rust)

Open Questions

None

Copilot

Pull request overview

Adds a new satisfaction-problem model, RectilinearPictureCompression, to represent the NP-complete “cover 1-cells with ≤K all-1 rectangles” decision problem, along with CLI creation support and documentation/example catalog integration.

Changes:

Introduces RectilinearPictureCompression model + schema registration + example-db spec.
Adds unit tests, CLI pred create support, and fixture examples for the new model.
Regenerates/updates docs artifacts (schemas + reduction graph) and extends the paper with the new definition.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
`src/models/misc/rectilinear_picture_compression.rs`	New model implementation, schema registration, variants, and example-db spec.
`src/models/misc/mod.rs`	Wires the new misc model module + re-export + example-db spec inclusion.
`src/models/mod.rs`	Re-exports the new model from the top-level `models` module.
`src/unit_tests/models/misc/rectilinear_picture_compression.rs`	Adds comprehensive unit tests for construction, maximal-rectangle enumeration, evaluation, brute-force behavior, and serialization.
`src/unit_tests/trait_consistency.rs`	Adds trait-consistency coverage for the new problem type.
`problemreductions-cli/src/commands/create.rs`	Adds `pred create RectilinearPictureCompression` instance construction + example flag string.
`problemreductions-cli/src/cli.rs`	Updates help text to document flags for the new problem.
`src/example_db/fixtures/examples.json`	Adds a fixture example instance + sample configs for the example database.
`docs/src/reductions/problem_schemas.json`	Adds generated schema entry for the new problem.
`docs/src/reductions/reduction_graph.json`	Adds generated variant node for the new problem (and reindexes edges accordingly).
`docs/paper/reductions.typ`	Adds paper definition/section + figure for Rectilinear Picture Compression.

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+        // Step 3: Filter to keep only maximal rectangles.
+        // A rectangle A is dominated by rectangle B if B contains A as a proper subset.
+        let mut maximal = Vec::new();
+        for &(r1, c1, r2, c2) in &candidates {
+            let is_dominated = candidates.iter().any(|&(sr1, sc1, sr2, sc2)| {
+                sr1 <= r1
+                    && sc1 <= c1
+                    && sr2 >= r2
+                    && sc2 >= c2
+                    && (sr1, sc1, sr2, sc2) != (r1, c1, r2, c2)
+            });
+            if !is_dominated {
+                maximal.push((r1, c1, r2, c2));
+            }


+/// Given an m x n binary matrix M and a positive integer K, determine whether
+/// there exists a collection of at most K axis-aligned all-1 rectangles that
+/// covers precisely the 1-entries of M.


+      covering entries $M_(i j)$ for $a lt.eq i lt.eq b$ and $c lt.eq j lt.eq d$,
+      where every covered entry must satisfy $M_(i j) = 1$.
+    ][
+    Rectilinear Picture Compression is a classical NP-complete problem from Garey & Johnson (A4 SR25, p.~232) @garey1979. It arises naturally in image compression, DNA microarray design, integrated circuit manufacturing, and access control list minimization. NP-completeness was established by Masek (1978) via transformation from 3SAT. The best known exact algorithm runs in $O^*(2^(m n))$ by brute-force enumeration over all possible rectangle selections#footnote[No algorithm improving on brute-force is known for the general case of Rectilinear Picture Compression.].


+        let m = self.num_rows();
+        let n = self.num_cols();
+
+        // Step 1: Enumerate all all-1 rectangles by extending from each (r1, c1).


…43-rectilinear-picture-compression # Conflicts: # docs/src/reductions/problem_schemas.json # docs/src/reductions/reduction_graph.json # problemreductions-cli/src/commands/create.rs # src/models/misc/mod.rs # src/models/mod.rs # src/unit_tests/trait_consistency.rs

- allow RectilinearPictureCompression through the crate prelude and add a regression test - replace quadratic maximal-rectangle filtering with prefix-sum extension checks - align Rectilinear documentation with bound_k = 0 support and rephrase the paper complexity note

GiggleLiu · 2026-03-16T20:12:07Z

Review Pipeline Report

Check	Result
Copilot comments	4 fixed
Issue/human comments	checked, no open items
Structural review	passed after follow-up fixes
CI	green
Agentic test	passed
Needs human decision	none
Board	Review pool → Under review → Final review

Follow-up fixes

Corrected schema-driven pred create help for RectilinearPictureCompression and LengthBoundedDisjointPaths.
Made shared pred create --help descriptions for --matrix and --k generic instead of problem-specific.
Made pred inspect report only actually usable solvers for the loaded problem.
Validated ragged boolean matrices in pred create so malformed input now returns a user-facing error instead of panicking.
Added/updated CLI docs for the RectilinearPictureCompression workflow and aligned the paper example wording.
Added CLI regressions covering the new help, inspect, and validation behavior.

Remaining issues for final review

None.

🤖 Generated by review-pipeline

Resolve conflicts: keep RectilinearPictureCompression alongside newly added models (ConsecutiveOnesSubmatrix, PrimeAttributeName, StaffScheduling, etc.). Adapt ModelExampleSpec to the new API (instance/optimal_config/optimal_value fields instead of build closure). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

The parse_bool_rows refactor catches ragged rows before validate_staff_scheduling_args, producing a different error message. Update the assertion to accept either message. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

zazabap

Final review passed. All CI green, implementation complete, 21 tests, paper section with figure. LGTM.

Add plan for #443: RectilinearPictureCompression

fbc3485

GiggleLiu and others added 4 commits March 17, 2026 00:13

Add RectilinearPictureCompression problem-def entry to paper

23188f0

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Review fixes: precompute maximal rectangles, return slice from matrix…

f936eee

…(), add solution count assertion

chore: remove plan file after implementation

a7010ff

GiggleLiu requested a review from Copilot March 16, 2026 16:35

Copilot started reviewing on behalf of GiggleLiu March 16, 2026 16:35 View session

Copilot AI reviewed Mar 16, 2026

View reviewed changes

GiggleLiu added 3 commits March 17, 2026 03:24

fix: tighten review follow-ups for PR 677

645e7a1

zazabap and others added 2 commits March 19, 2026 07:12

zazabap approved these changes Mar 19, 2026

View reviewed changes

zazabap mentioned this pull request Mar 19, 2026

[Model] RectilinearPictureCompression #443

Closed

3 tasks

zazabap merged commit deca9c7 into main Mar 19, 2026
5 checks passed

GiggleLiu deleted the issue-443-rectilinear-picture-compression branch April 12, 2026 00:53

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Fix #443: Add RectilinearPictureCompression model#677

Fix #443: Add RectilinearPictureCompression model#677
zazabap merged 10 commits intomainfrom
issue-443-rectilinear-picture-compression

GiggleLiu commented Mar 16, 2026

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GiggleLiu commented Mar 16, 2026

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GiggleLiu commented Mar 16, 2026

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GiggleLiu commented Mar 16, 2026

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