#! perl -slw
use strict;
local $, = ' ';

my( $A, $B, $C ) = ( '', '', 0 );

sub query{ 
    my $i = shift;
    my $a = vec $A, $i, 32;
    my $b = vec $B, $a, 32;
    return (0 <= $a and $a < $C and $b == $i ) ? 1 : 0;
}

sub insert{
    my $i = shift;
    if( !query( $i ) ) {
        vec( $B, $C, 32 ) = $i;
        vec( $A, $i, 32 ) = $C;
        $C++
    }
}

sub del{
    my $i = shift;
    if( query( $i ) ) {
        my $a = vec( $A, $i, 32 );
        my $b = vec( $B, --$C, 32 );
        vec( $B, $a, 32 ) = $b;
        vec( $A, $b, 32 ) = $a;
    }
}

sub clear{
    $C = 0;
}

my @numbers = map{ int rand( 2**16 ) } 1 .. 10;
    
print 'Query before insert';
printf "%5d : %s\n", $_, query( $_ ) for @numbers;

insert $_ for @numbers;

print "\nQuery after insert";
printf "%5d : %s\n", $_, query( $_ ) for @numbers;

del $_ for @numbers[ 0..4 ]; ## Delete half

print "\nQuery after deleting half";
printf "%5d : %s\n", $_, query( $_ ) for @numbers;

del $_ for @numbers; ## Delete them all regardless if they still exist
+s

print "\nQuery after deleting the rest";
printf "%5d : %s\n", $_, query( $_ ) for @numbers;
__END__
P:\test>337432
Query before insert
22456 : 0
11958 : 0
15260 : 0
34466 : 0
23110 : 0
 9114 : 0
21434 : 0
37988 : 0
32562 : 0
55488 : 0

Query after insert
22456 : 1
11958 : 1
15260 : 1
34466 : 1
23110 : 1
 9114 : 1
21434 : 1
37988 : 1
32562 : 1
55488 : 1

Query after deleting half
22456 : 0
11958 : 0
15260 : 0
34466 : 0
23110 : 0
 9114 : 0
21434 : 1
37988 : 1
32562 : 1
55488 : 1

Query after deleting the rest
22456 : 0
11958 : 0
15260 : 0
34466 : 0
23110 : 0
 9114 : 0
21434 : 0
37988 : 0
32562 : 0
55488 : 0
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