Easiest looking up if you keep track of which array each number goes to: 
my @which;
$which[$_] = "array1" for @array1;
$which[$_] = "array2" for @array2;
$which[$_] = "array3" for @array3;

my @pairs = @array4;
while (my ($one,$two) = splice(@pairs,0,2)) {
   print "$one and $two are in $which[$one] and $which[$two]\n";
}

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If the numbers are negative or non-integral or too big, use a hash %which instead of the array @which.

In reply to Re: matching values in arrays by ysth
in thread matching values in arrays by Anonymous Monk

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