my @a_indices = (1,3,5);
my @b = map {my $t = $_; (grep {$t == $_} @a_indices) ? undef : $t} 0 .. 9;

print join ', ', grep {defined} @b;

##</code><code>##

0, 2, 4, 6, 7, 8, 9

##</code><code>##

my @a_indices = (1,3,5);
my %hasIndex = map {$_ => undef} @a_indices;
my @b = map {exists $hasIndex{$_} ? undef : $_} 0 .. 9;