like this

use strict;
use warnings;

use Data::Dump qw/pp/;


open my $qqq,"<","qqq.txt" or die "Open qqq failed $!";
open my $exp,"<","exp.txt" or die "Open exp failed $!";

my @exp = <$exp>;
chomp @exp;


my %qqq;
while (<$qqq>) {
  my ($value,$key) = split /\s+/;
  push @{$qqq{$key}},$value;
}

#pp \%qqq,\@exp;

print "$_: @{$qqq{$_}}\n" for @exp;
[download]

out

a: 1 11
c: 333
[download]