18 lines
483 B
Plaintext
18 lines
483 B
Plaintext
# our deficient list
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L :=
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[ "ABCD", "CABD", "ACDB", "DACB", "BCDA",
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"ACBD", "ADCB", "CDAB", "DABC", "BCAD",
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"CADB", "CDBA", "CBAD", "ABDC", "ADBC",
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"BDCA", "DCBA", "BACD", "BADC", "BDAC",
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"CBDA", "DBCA", "DCAB" ];
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# convert L to permutations on 1..4
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u := List(L, s -> List([1..4], i -> Position("ABCD", s[i])));
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# set difference (with all permutations)
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v := Difference(PermutationsList([1..4]), u);
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# convert back to letters
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s := "ABCD";
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List(v, p -> List(p, i -> s[i]));
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