Re: An easier way to construct lists of numbers?

[Chady]

Your code does not run and has a lot of errors, anyway, if I understand your code correctly, here's something that will work for you.

use Data::Dumper;

# note that you do not need to explicitly fill in the 
# elements of the array one by one, make use of
# perl's lists.
 
my @lite = (
    [qw/2 5 0 999 999 0/],
    [qw/4 3 0 999 999/],
    [qw/1 4 0 999 999/],
    [qw/1 4 0 999 999/],
    [qw/4 1 0 999 999/]
);

my %h;

foreach (@lite) {
    # construct a key made of the X value x the Y 
    # value and count on that being uniq.
    my $xy = $_->[0] . 'x' . $_->[1];

    # hash keys are uniq,
    # so we make the value an array reference 
    # containing the original x and y values.
    $h{$xy} = [$_->[0], $_->[1]];
}

# just retrieve the values from the hash.
my @filtered = values %h;

print Dumper(\@filtered);

[Skeeve]

I think he just wants to search the numbers and doesn't care whether it's x or y. So your hash asignment becomes:

++$h{$_->[0]};
++$h{$_->[1]};

and the result is simply printed with:

print join(' ',sort keys %h),"\n";

[yosefm]

Very nice, Chady.

I'd like to add a few things:

First, to filter out the unused ($lite[$something][5]) you can change:


$h{$xy} = [$_->[0], $_->[1]];

to:


$h{$xy} = [$_->[0], $_->[1]] if $_->[5];

Second, when you write a loop, you should try to include only the essential stuff in it, so your program runs faster and consumes less resources. so this:

for my $o (0 .. $#line) {
    select BLA
    print ...
    select STDOUT
}


can become:

select BLA;
for my $o (0 .. $#line) {
    print ...
}
select STDOUT;

But it's also possible to give a file handle to print, like so: print HANDLE "Something\n"; and then you don't have to select and reselect at-all.