Fix SetCoverVerifier accepting subsets not in S, ignoring K - #508
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Fix SetCoverVerifier accepting subsets not in S, ignoring K#508Trosper3 wants to merge 1 commit into
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… bound K The verifier flattened certificates into a bag of loose elements and only checked whether they covered the universe, so any collection of made-up subsets (or even bare elements with no subset structure) that happened to cover U was accepted. Now parses the certificate's actual subset structure via UtilCollection and enforces all three parts of the decision problem: each subset is a genuine member of S, the subset count is <= K, and the union covers U.
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Superseded by the fix+test file already open in PR #508 (fixes the subset-membership/K check and adds fuller test coverage vs. this PR's 3-test format smoke check). Keeping the instanceFormat/certificateFormat declaration changes; only dropping the file that would otherwise collide on merge.
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Summary
SetCoverVerifierflattened certificates into a bag of loose elements (Replace("},{", ",").Replace("{", "").Replace("}", "")), discarding subset structure entirely, and only checked whether the flattened bag covered the universeU. Any collection of made-up subsets — or even bare elements with no subset structure at all — that happened to coverUwas accepted, and the cardinality boundKwas never read.parseCertificatenow usesSPADE.UtilCollectionto parse the certificate's actual nested subset structure.verifyenforces all three parts of the Set Cover decision problem: each listed subset is a genuine (order-independent) member ofS, the subset count is<= K, and the union of accepted subsets coversU. Parse failures are caught and returnfalse, matchingKnapsackVerifier's existing convention.SetCoverBruteForcecalls this verifier as its own search oracle and always builds certificates from genuine indices intoS, so this tightening doesn't change the solver's behavior — confirmed by the full suite passing.Closes #258
Test plan
dotnet test --filter "...SETCOVER_Tests"— 10/10 passed (new test file; no prior tests existed for this problem)dotnet build --configuration Release(gates ondotnet format --verify-no-changes) — cleandotnet test(full suite) — 908/908 passed