trivially fixable by including start-of-string and end-of-string as tokens in the initial string breakdown, so instead of analyzing {abc, ab, bc, a, b, c} as candidate regexes, you start out analyzing {^abc, abc$, ^ab, abc, bc$, ^a, ab, bc, c$, ^, a, b, c, $}; would rapidly home in on c$ as an optimal solution.
Thus would fail against a 'must fail' target of abcabc, but then you fix that by extending the maximum allowable regex fragment length from 4 to 5 and it'll find ^abc$. More generally, you extend the maximum allowable regex count to the longest 'must match string' plus 2, and it'll always succeed, even if it has to create a regex consisting of ^word1$|^word2$|^word3$...
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I think it fails for: findregex(set(['abc']), set(['abcd']))
Pretty sure that's impossible within given constraints (only disjunction positive regexes allowed).
trivially fixable by including start-of-string and end-of-string as tokens in the initial string breakdown, so instead of analyzing {abc, ab, bc, a, b, c} as candidate regexes, you start out analyzing {^abc, abc$, ^ab, abc, bc$, ^a, ab, bc, c$, ^, a, b, c, $}; would rapidly home in on c$ as an optimal solution.
Thus would fail against a 'must fail' target of abcabc, but then you fix that by extending the maximum allowable regex fragment length from 4 to 5 and it'll find ^abc$. More generally, you extend the maximum allowable regex count to the longest 'must match string' plus 2, and it'll always succeed, even if it has to create a regex consisting of ^word1$|^word2$|^word3$...