String permutations

Question

Print the biggest-size subset of strings in the input that are all permutations of each other. If there are ties, any one will do. If no strings are permutations of each other (for example, only one string was given or the strings contain distinct characters), this is just one of the strings. If no strings were passed in , do not output anything or output an empty list.

Test cases:

Input => Output
["ABCDE", "EDBCA", "XYZ", "ZYX", "ZXY"] => ["XYZ", "ZYX", "ZXY"]
["A"] => ["A"]

Answer 1

05AB1E, 6 bytes

.¡{}éθ

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.¡ }      # group the input strings by:
  {       #  sort (all permutations of each other will be identical when sorted)
    é     # sort the groups by length
     θ    # output the last (longest) group

Answer 2

T-SQL, 267 bytes

SQL queries was totally made to solve this type of question

SELECT top 1WITH TIES x FROM(SELECT(SELECT a FROM(SELECT
top 999substring(x,number+1,1)a,*FROM
@,spt_values WHERE type='P'and number<len(x)ORDER BY a)c
WHERE x=t.x for xml path(''),type).value('.','char(9)')v,x FROM @ t)z 
ORDER BY-count(*)over(PARTITION BY v),-len(x)

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Answer 3

Japt -h, 6 5 bytes

üñ ñl

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üñ ñl     :Implicit input of array
ü         :Sort & group by
 ñ        :  Sorted strings
   ñ      :Sort by
    l     :  Length
          :Implicit output of last element

Answer 4

Perl 6, 36 bytes

{max .classify(~*.comb.sort){*}||''}

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Output an empty string for an empty input. If we could output something else, for example -Inf, then this could be:

Perl 6, 31 bytes

*.classify(~*.comb.sort){*}.max

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Answer 5

J, 19 bytes

0({>\:#&>)/:~&></.]

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-2 bytes thanks to FrownyFrog

Similar approach to Grimmy's answer.

Answer 6

Python 2, 79 77 bytes

lambda A,S=sorted:A and max([[y for y in A if S(x)==S(y)]for x in A],key=len)

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2 bytes thx to wilkben.

The A and... is only required to deal with the empty input.

Answer 7

Clojure, 54 bytes

#(some val(sort-by(comp count val)>(group-by sort %)))

Returns nil for empty input.

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