Find matching arrays in hash of arrays

CrackBaby has asked for the wisdom of the Perl Monks concerning the following question:

Good morning Monks. I hope some more experienced Perl programmers can help me with a small task. I need to find and report duplicate arrays in a hash of arrays. I do not care about unique arrays, I need to know which arrays exist in the hash 2 or more times. Something like this:

my %hoa = (
    array1 => [ 1,2,3 ],
    array2 => [ 7,8,9 ],
    array3 => [ 1,2,3 ],
    array4 => [ 7,8,9 ],
    array5 => [ 9,9,9 ],
    array6 => [ 1,2,3 ],
);
[download]

I need to know which arrays exist 2 or more times - in this example I need to know that array1, array3 and array6 match - and also array2 and array4 match. Thank you for your help.

Comment on Find matching arrays in hash of arrays Download Code

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Re: Find matching arrays in hash of arrays by moritz (Cardinal) on Nov 04, 2008 at 17:30 UTC
Something along these lines: `use strict; use warnings; my %hoa = ( array1 => [ 1,2,3 ], array2 => [ 7,8,9 ], array3 => [ 1,2,3 ], array4 => [ 7,8,9 ], array5 => [ 9,9,9 ], array6 => [ 1,2,3 ], ); my %counts; while (my ($k, $v) = each %hoa) { push @{$counts{join '\|', @$v}}, $k; } print "Duplicates:\n"; for (keys %counts) { next if @{$counts{$_}} < 2; print join ', ', @{$counts{$_}}; print "\n"; } __END__ Duplicates: array1, array3, array6 array4, array2` [download]	[reply] [d/l]
Re^2: Find matching arrays in hash of arrays by CrackBaby (Initiate) on Nov 04, 2008 at 20:09 UTC
Yes, that work perfectly, thank you.	[reply]
Re: Find matching arrays in hash of arrays by GrandFather (Saint) on Nov 04, 2008 at 19:52 UTC
How big are the arrays? If they are small then you could: `use warnings; use strict; my %hoa = ( array1 => [ 1,2,3 ], array2 => [ 7,8,9 ], array3 => [ 1,2,3 ], array4 => [ 7,8,9 ], array5 => [ 9,9,9 ], array6 => [ 1,2,3 ], ); my %dups; push @{$dups{join '~', @{$hoa{$_}}}}, $_ for sort keys %hoa; print map {join (" ", @{$dups{$_}}), "\n"} grep @{$dups{$_}} > 1, keys + %dups;` [download] Prints: `array1 array3 array6 array2 array4` [download] Perl reduces RSI - it saves typing	[reply] [d/l] [select]