Re: how to simplify this script

Richard Lee wrote:
> " It should include '1 2 3' because '1 2 3', '1 2 4', '1 2 7', '1 2 8',
> '1 2 9' = '1 2'(the common number from the list) + anynumber. "
> as any of them contains 1 and 2 and I don't understand why '1 2 3' was
> picked.

My interpretation: Because it's the first element of those with 1 and 2 
in them. In other words, the order in which the elements appear in 
@[EMAIL PROTECTED]
 is im****tant for the result.

> Also can someone explain to me in detail what Gunnar Hjalmarsson's
> solution is doing?
> 
> ------------ code of Gunnar's ----------------
> 
> my $numbers_wanted = 2;
> my ( @[EMAIL PROTECTED]
 @[EMAIL PROTECTED]
 );
> 
> LOOP: foreach ( @[EMAIL PROTECTED]
 ) {
>     my @[EMAIL PROTECTED]
 = split;
>     foreach my $num ( @[EMAIL PROTECTED]
 ) {
>         next LOOP if grep( $num->{$_}, @[EMAIL PROTECTED]
 ) >= $numbers_wanted;
>     }
>     push @[EMAIL PROTECTED]
 $_;
>     push @[EMAIL PROTECTED]
 { map { $_ => 1 } @[EMAIL PROTECTED]
 };
> }
> 
> print "$_\n" for @[EMAIL PROTECTED]
 iterates over @[EMAIL PROTECTED]
 and stores some of the elements in @[EMAIL PROTECTED]
 
based on (my interpretation of) the OP's criteria. There is nothing 
mysterious with the code; everything can be looked up in the Perl docs.

@[EMAIL PROTECTED]
 is a help variable where the numbers in previously stored 
elements are made conveniently accessible for lookups. The expression

     map { $_ => 1 } @[EMAIL PROTECTED]
 a key/value list where the elements of @[EMAIL PROTECTED]
 are the keys (see 
"perldoc -f map"), and

     push @[EMAIL PROTECTED]
 { map { $_ => 1 } @[EMAIL PROTECTED]
 };

makes the list an anonymous hash and adds a reference to that hash to 
@[EMAIL PROTECTED]
() is used in scalar context to compare the elements with previously 
stored elements and test against the OP's criteria.

     perldoc -f grep

-- 
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl