#! perl -slw
use strict;

sub adjSets{
    my $min = shift;
    map {
        my $start = $_;
        map { [ @_[ $start .. $_ ] ] } $min .. $#_;
    } 0 .. $#_ - $min;
}

print "@$_" for adjSets( 2, 'A'..'E' );;
__END__
A B C
A B C D
A B C D E
B C
B C D
B C D E
C
C D
C D E