Ah, now I finally understand what you want. (:
You need a more complex data structure. You can
wrap a nice interface around it if you like, but I'll
leave that part up to you (or others).
I think you've found a reason to implement a linked list
in Perl (normally you don't need such things in Perl). I
went with a circular, doubly-linked list for ease of
implementation (where "turn 0" is a dummy turn used to find
the first and last turns):
my %turn= (
0=>{Next=>5,Prev=>53},
5=>{Turn=>"turn 0",Prev=>0,Next=>28},
28=>{Turn=>"turn 28",Prev=>5,Next=>53},
53=>{Turn=>"turn 53",Prev=>28,Next=>0},
);
sub pushTurn {
my( $num, $turn )= @_;
my $last= $turn{0}{Prev};
$turn{$num}= {Turn=>$turn,Prev=>$last,Next=>0};
$turn{0}{Prev}= $num;
$turn{$last}{Next}= $num;
}
sub deleTurn {
my( $num )= @_;
my( $prev, $next )= @{ $turn{$num} }{qw( Prev Next )};
$turn{$prev}{Next}= $next;
$turn{$next}{Prev}= $prev;
delete $turn{$num};
}
I hope that is close enough to correct that you can get
an implementation working. {-:
Use:
my %turn= ( 0=>{Next=>0,Prev=>0} );
to bootstrap the data structure.
-
tye
(but my friends call me "Tye") |