You want to move certain array elements to the end? I'd do it like this:

my @front, @back;
while( @array1 ) {
    if( exists $skip{$_->[0]} ) {
        push @back, $_;
    else {
        push @front, $_;
    }
}
my @array2 = (@front, @back);
[download]

The while loop could also be written as

    push @{exists $skip{$_->[0]} ? \@back : \@front}, $_;
[download]

... and from there you could always carry on as far as

... and do away with the while but that requires a much more advanced understanding of Perl and I'm not sure that it's any clearer. And of course it becomes a real pain to step through it in the debugger... And of course I may have completely misunderstood what you're trying to do :)

    #!/usr/bin/perl -w

    use strict;

    my @array = ([1], [2], [3], [4], [5]);
    my %skip  = (3 => 1);

    my @keep  = grep {not exists $skip{$_->[0]}} @array;
    my @skip  = grep {    exists $skip{$_->[0]}} @array;

    my @new   = (@keep, @skip);
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If the array of data is very large it may be inefficient to use two calls to grep. In which case a while loop solution as shown by grinder would be better.

--
John.

    #!/usr/bin/perl -wl

    use strict;

    my @array = (2, 3, 4, 5, 1, 7, 11, 8, 9,  6, 10, "End" );
    my %skip  = (3 => 1, 6 => 1);
    my @new   = sort {exists $skip{$a} <=> exists $skip{$b}} @array;


    print "@new";

    __END__
    $ perl5.8.0 sort_end2.pl
    2 4 5 1 7 11 8 9 10 End 3 6

    $ perl5.6.0 sort_end2.pl
    2 End 4 5 1 7 11 8 9 10 3 6
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Update: Changed the test data to make it clearer what the desired output was.

The difference is due to the the fact that 5.8 uses merge sort and 5.6 uses quick sort. From perlfunc in 5.8:

Perl 5.6 and earlier used a quicksort algorithm to implement sort. That algorithm was not stable,and could go quadratic. (A stable sort preserves the input order of elements that compare equal.

--
John.