Re: Generating a list of numbers from other lists

[Marshall]

I made a hash out of the numbers to search for list. Then ran through the main list, kept the relevant matching lines, then sorted that list by the first number. While doing that I kept a running sum of each section in %sums. I wasn't sure what the output should look like.

Update: added the sum calculation. And I now see that there is some text that you want to skip, use a regex for that. Anyway you have another solution.

#!/usr/bin/perl -w
use strict;
$|=1;

my @numberList = qw (20 30 50); #you get this from a file

my %numberHash = map{$_ => 1}@numberList;

my @result;
my %sums;
while (<DATA>)
{
   chomp;
   my ($first, $second) = split;
   
   if ($numberHash{$first})
   {
      push @result, $_;
      $sums{$first}+= $second;
   }
}

@result = sort{ my($firstA) = split(' ',$a);
                my($firstB) = split(' ',$b);
                   $firstA <=> $firstB 
              }@result;

foreach (@result)
{
   my ($first) = split;
   print "$_ $sums{$first}\n";
}

#not sure what format you want output in
=prints
20 23424 332444
20 56756 332444
20 82757 332444
20 83758 332444
20 09347 332444
20 76402 332444
30 91857 364101
30 92785 364101
30 89275 364101
30 90184 364101
50 29349 184748
50 71674 184748
50 83725 184748
=cut

__DATA__
10 23432
20 23424
60 45567
20 56756
30 91857
50 29349
10 93729
80 82374
20 82757
30 92785
50 71674
70 81747
20 83758
30 89275
10 19594
60 09214
20 09347
50 83725
90 91845
20 76402
30 90184

[mbethke]

To avoid the expensive split in a sort block, you could separate the results in lists of their own using a second hash:

my (%result, %sums);
while (<DATA>) {
    chomp;
    my ($first, $second) = split;

    if ($numberHash{$first}) {
        push @{$result{$first}}, $second;
        $sums{$first}+= $second;
    }
}

foreach my $first (sort { $a <=> $b } keys %result) {
    foreach my $second (@{$result{$first}}) {
        print "$first $second $sums{$first}\n";
    }
}

Just in case the OP ever wants to process tens of megabytes that way :)

[Marshall]

I certainly appreciate your point! And it is well taken.

I try to modulate my response to the skill level reflected by the original question (with an imperfect heuristic). Sometimes I am more effective at this than at other times. The HoA (Hash of Array) syntax can often be a bit confusing for beginners. I just avoided this "what heck does push @{$result{$first}}"? mean by not doing that. Anyway, I think the collective "Monk Wisdom" has done well for this OP - there a several alternatives, all of which will probably work out just fine.