my @ary = qw( 0 1 5 5 5 0 5 5 5 1 0 );

$" = "~";

print "@ary\n";

my $deletions = 0;
for my $i ( 0 .. $#ary ) {
    if ($ary[$i-$deletions] == 5) {
        splice @ary, ($i-$deletions), 1;
        $deletions++;
    } 
}

print "@ary\n";