Constrain the unique unit square to a closed D4 fundamental region once its placement is known. This preserves one representative of every board-orientation orbit without assigning identities to repeated squares.
Keep a symmetry-disabled benchmark path, document the proof and measurements, and cover generic, diagonal, midline, corner, and centre orbits.
Tests: Release, Debug, ASan, and UBSan CTest (11 passed each)
Refs: #3
Make candidate ordering an explicit deterministic policy and benchmark ascending, descending, and exact-width-first choices. Keep ascending as the default because it produces the best measured time to first solution despite best-fit's slightly smaller tree.
Retain the benchmark v1 interface and document why randomized and duplicate-work portfolio policies are deferred.
Tests: Release and Debug CTest (10 passed each)
Refs: #12
Represent partial placements as column heights and branch on the narrowest local valley. This removes the board-area cell state and makes first-solution search substantially smaller for feasible orders.
Expose direct-search and candidate-order benchmark controls so the skyline core can be measured independently of odd-order construction. Document the completeness argument and the 10/11 test-tier decision.
Tests: Release, Debug, ASan, and UBSan CTest (10 passed each)
Refs: #4
Provide a separately installed OR-Tools model to compare a generic constraint solver with the native first-solution path without adding a production or default-test dependency.
Use no-overlap, exact-fill, edge and equal-copy symmetry constraints, validate placements independently, and record model size, memory, worker count and timings for orders 8 and 9. Keep the tool only as a reference and defer DLX absent new evidence.
Tests: Release CTest (9 passed)
Tests: Python reference tests and compilation checks
Tests: independently validated CP-SAT orders 8 and 9
Refs: #5
Avoid repeating the exponential search for odd orders at least nine. Search the even predecessor, translate its row-major placements to the enlarged board, and tile the new border.
Keep direct search and construction explicit so benchmarks can report their costs separately. Verify the routed order-9 result independently and require its search counters to match order 8.
Tests: Release, Debug, ASan and UBSan CTest (8 passed each)
Refs: #6
Add an opt-in benchmark probe and JSON runner that separate solve, construction, validation, and rendering time. Record stable search counters, environment metadata, warm-up and repetition policy, timeouts, errors, median spread, and instrumentation overhead.
Compile production solving without counters and interleave counted and plain trials when measuring overhead. Keep heavyweight cases outside the default correctness path while testing counter and report behavior cheaply.
Tests: Debug and Release CTest suites (7 passed each)
Refs: #8
Exercise both the trivial order-1 solution and the feasible order-8 solution through the independent placement validator.
With the existing completion ordering, the focused test reports a heap-buffer-overflow under AddressSanitizer before validation can run.
Refs: #14
Exercise Results::output() with the known order-8 fixture so Debug builds compile and run the rendering assertions. Check the output dimensions and ensure the valid tiling leaves no unrendered cells.
The test passes in Release and currently fails to compile in Debug because Results::set() refers to the nonexistent grid_ member.
Refs: #7
Establish a CTest harness before changing solver behavior. Validate board dimensions, multiplicities, bounds, overlap and coverage against independent placement data, including known order-8 and constructed order-9 fixtures.
Document Debug and sanitizer workflows while keeping the defects tracked by #7 and #14 separate. Prepare a result adapter so the feasible solver regression can be enabled with the completion fix.
Tests: Release, ASan and UBSan CTest suites (3 passed each)
Refs: #1
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