#!/usr/bin/perl -- # -*-PERL-*-
use Data::Dumper;
use Benchmark 'cmpthese';

my @data = ([1,2], [1,3], [2,3], [2,4], [3,4]);
my @data_longrand = map { [ int( rand( 25 ) ), int( rand( 25 ) ) ] } 1 .. 10_000;

cmpthese( 50_000,
	  {  ( map { $_ => qq[$_( \@data )] } qw/ pg scooterm ewijaya aighearach / ),
	     ( map { $_.'_longrand' => qq[$_( \@data_longrand )] } qw/ pg scooterm ewijaya aighearach / ),
	  },
	);

sub pg {
    my %vertices;

    for my $i ( 0 .. $#_ ) {
        $vertices{$_[$i][$_]} = 1 for (0 .. $#{$_[$i]});
    }
    return sort keys %vertices;
}

sub scooterm {
    my  %hTemp;
    my  @aTemp = map{@{$_}} @_;
    @hTemp{@aTemp}  = ();
    return sort keys %hTemp;
}

sub aighearach {
    my ( %unique );
    for ( my $i = 0; $i < @_; $i++ ) {
        @unique{@{$_[$i]}} = undef;
    }
    return sort keys %unique;
}

sub ewijaya {
    my @edges = @_;
    my @vertices;
    my @uniqv; 

    for my $i ( 0 .. $#edges ) {
	for my $j ( 0 .. $#{$edges[$i]} ) {
	    push @vertices, $edges[$i][$j];
	}
    }

    @uniqv = sort keys %{{map {$_,1} @vertices}};
    return @uniqv;
}

__END__