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MinHash Jaccard estimation: agreement normalised like a set Jaccard · case 04

Similarity estimates are systematically deflated for partially overlapping sets.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Input {k, A, B} integer sets. Signature component i is min over v of (A_i v + B_i) mod 2^31-1 with fixed coefficients. The estimate is the fraction of positions where both signatures agree, rounded to 4 decimals. Two empty sets have undefined similarity (None, with empty signatures); exactly one empty set gives 0.0. Return [sigA, sigB, estimate].

Why this case matters

Near-duplicate detection and set-similarity joins compare MinHash signatures instead of the sets; signature and comparison rules must match exactly across producers.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
overlapping sets k=6	`[[27887117, 330532488, 78683252, 134317934, 178394676, 329803467], [83636661, 330532488, 78683252, 134317934, 144309083, 104634115], 0.3333]`	`[[27887117, 330532488, 78683252, 134317934, 178394676, 329803467], [83636661, 330532488, 78683252, 134317934, 144309083, 104634115], 0.5]`	Failed

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