sorting one array, matching the second one

Posted on 2009-03-30
Last Modified: 2012-05-06
I have two arrays of strings, the left one needs to be natural sorted, I can do this however array2 has to be modified to maintain the index consistency.

@array1   @array2
1 --> b      1 --> bla
2 --> d      2 --> bla2
3 --> a1    3 --> bla3
4 --> a10  4 --> bla4
5 --> a20  5 --> bla5
6 --> a2    6 --> bla6

1 --> a1    1 --> bla3
2 --> a2    2 --> bla6
3 --> a10  3 --> bla4
4 --> a20  4 --> bla5
5 --> b      5 --> bla
6 --> d      6 --> bla2

i'm using a modified version of tye algorithm found on perkmonkey site for the natsort on array1 but then how would I order array2.

my @sorted = @list[
    map { unpack "N", substr($_,-4) }
    map {
        my $key = $list[$_];
        $key =~ s[(\d+)][ pack "N", $1 ]ge;
        $key . pack "N", $_
    } 0..$#list

Would you use a two dimensional array instead?
I want to make sure i'm doing this the most efficient way as the list can get long, any help appreciated
Question by:NewtonianB
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LVL 39

Expert Comment

ID: 24021882
I think a 2D array (or actually an array-of-arrays) would be better.  Here is an example:

my @array1 = (qw(b d a1 a10 a20 a2));
my @array2 = (qw(bla bla2 bla3 bla4 bla5 bla6));
##### Build array of array
my @AoA;
for(my $i=0; $i<=$#array1; $i++) {
	push @AoA, [$array1[$i], $array2[$i]];
##### Sort
my @AoA_sorted = sort {$a->[0] cmp $b->[0]} @AoA;
##### get original arrays, but sorted
@array1 = map{$_->[0]} @AoA_sorted;
@array2 = map{$_->[1]} @AoA_sorted;

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Author Comment

ID: 24022150
Thanks Adam! but It needs to be natural sorted instead of sort which is what's creating my complication, how would I use the above natural sorting algorithm or another one with your code
example of proper sort: a1 b1 a10 b1 b20  instead of  a1 a10 b1 b20

Author Comment

ID: 24022460
i meant for example a1 a2 a3 a10 a12  instead of  a1 a10 a12 a2 a3
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LVL 39

Accepted Solution

Adam314 earned 500 total points
ID: 24022640

##### Build array of array
my @AoA;
for(my $i=0; $i<=$#array1; $i++) {
	my $key = $array1[$i];
	$key =~ s/(\d+)/pack "N", $1/ge;
	push @AoA, [$key, $array1[$i], $array2[$i]];
##### Sort
my @AoA_sorted = sort {$a->[0] cmp $b->[0]} @AoA;
##### get original arrays, but sorted
@array1 = map{$_->[1]} @AoA_sorted;
@array2 = map{$_->[2]} @AoA_sorted;

Open in new window


Author Comment

ID: 24023289
that should work! thanks!

Last quick question,
What's the most efficient way to get a 2Dimensional array consisting of the last two columns of array AoA_sorted?

could i just do something like
my @arrayTwoDim = map{$_->[1], $_->[2]} @AoA_sorted;
LVL 39

Assisted Solution

Adam314 earned 500 total points
ID: 24023543
If you want to make a new @arrayTwoDim (you need the extra square brackets):
    my @arrayTwoDim = map{[$_->[1], $_->[2]]} @AoA_sorted;

If you want to change @AoA_sorted:
    shift @$_ foreach (@AoA_sorted);

Author Closing Comment

ID: 31564469
I could not have asked for a better help. Thank you so much!

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