my @results = ( $col[0], $col[3] );
for my $dataset (@data) {
    push @results, (
        sort {
            my $diff_a = $col[2] - $a->[1];
            $diff_a *= -1 if $diff_a < 0;
            my $diff_b = $col[2] - $b->[1];
            $diff_b *= -1 if $diff_b < 0;
            $diff_a <=> $diff_b;
          } @{ $dataset->{ $col[0] } }
    )[0]->[2];
}


##</code><code>##

my @results = ( $col[0], $col[3] );
for my $dataset (@data) {
    my ( $first ) = 
        sort {
            my $diff_a = $col[2] - $a->[1];
            $diff_a *= -1 if $diff_a < 0;
            my $diff_b = $col[2] - $b->[1];
            $diff_b *= -1 if $diff_b < 0;
            $diff_a <=> $diff_b;
          } @{ $dataset->{ $col[0] } }

    push @results, $first->[2];
}

##</code><code>##

my @results = ( $col[0], $col[3] );
for my $dataset (@data) {
    my @beef = @{ $dataset->{ $col[0] } };
    @beef = 
        sort {
            my $diff_a = $col[2] - $a->[1];
            $diff_a *= -1 if $diff_a < 0;
            my $diff_b = $col[2] - $b->[1];
            $diff_b *= -1 if $diff_b < 0;
            $diff_a <=> $diff_b;
          }   @beef;

    push @results, $beef[0]->[2];
}