Array unification problem has me in circles

tsk1979 has asked for the wisdom of the Perl Monks concerning the following question:

Hi have data present in 3 arrays key1, key2 and data The number of elements in the three arrays is same. I have to write all the elements in a file as

$key1[0]
$key2[0]
$data[0]

$key1[1]
$key2[1]
$data[1]
.
.
.
.
[download]

Pretty simple, eh? But there is a problem. If while parsing, a $data has appeared before, that should not be in the file. So lets say $data[45] has come before, in that case

$key1[45]
$key2[45]
$data[45]
[download]

Should not be dumped in the file. So I am uniquifying an array(which is pretty simple in itself), and controlling the printing of 2 other arrays using this. Any tips welcome!

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Re: Array unification problem has me in circles by graff (Chancellor) on Nov 07, 2007 at 09:02 UTC
`my %seen; for (0..$#data) { next if ( $seen{$data[$_]}++ ); print join "\n", $key1[$_], $key2[$_], $data[$_], ""; }` [download]	[reply] [d/l]
Re: Array unification problem has me in circles by moritz (Cardinal) on Nov 07, 2007 at 09:03 UTC
You can store strings in a hash as the hash keys, and while writing to your file you can always consult the hash to check if that key has already been printed.	[reply]
Re: Array unification problem has me in circles by tuxz0r (Pilgrim) on Nov 07, 2007 at 17:58 UTC
I'm not sure how you are looping through those arrays, but an easy way to make `@data` contain only unique items might go like so: `my %tmp = map { $_ => 1} @data; my @uniq_data = sort keys %tmp;` [download] Then, just use that to loop through the other structures, outputing defined keys only once. --- `echo S 1 [ Y V U \| perl -ane 'print reverse map { $_ = chr(ord($_)-1) } @F;'` Warning: Any code posted by tuxz0r is untested, unless otherwise stated, and is used at your own risk.	[reply] [d/l]
Re^2: Array unification problem has me in circles by dragonchild (Archbishop) on Nov 07, 2007 at 18:09 UTC
Or, written more cleanly: `use List::MoreUtils qw( uniq ); my @uniq_data = uniq @data;` [download] My criteria for good software: Does it work? Can someone else come in, make a change, and be reasonably certain no bugs were introduced?	[reply] [d/l]
Re^2: Array unification problem has me in circles by parv (Parson) on Nov 08, 2007 at 21:50 UTC
Could avoid setting the 1s since values are absolutely being ignored, but it's a two step process ... `my %tmp; @tmp{ @data } = ();` [download]	[reply] [d/l]


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