File Coverage

blib/lib/Graph/Maker/BinomialTree.pm
Criterion Covered Total %
statement 6 8 75.0
branch n/a
condition n/a
subroutine 3 3 100.0
pod n/a
total 9 11 81.8


line stmt bran cond sub pod time code
1             # Copyright 2015, 2016, 2017 Kevin Ryde
2             #
3             # This file is part of Graph-Maker-Other.
4             #
5             # This file is free software; you can redistribute it and/or modify it
6             # under the terms of the GNU General Public License as published by the Free
7             # Software Foundation; either version 3, or (at your option) any later
8             # version.
9             #
10             # This file is distributed in the hope that it will be useful, but
11             # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12             # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13             # for more details.
14             #
15             # You should have received a copy of the GNU General Public License along
16             # with Graph-Maker-Other. See the file COPYING. If not, see
17             # .
18              
19             package Graph::Maker::BinomialTree;
20 1     1   752 use 5.004;
  1         3  
21 1     1   5 use strict;
  1         1  
  1         16  
22 1     1   89 use Graph::Maker;
  0            
  0            
23              
24             use vars '$VERSION','@ISA';
25             $VERSION = 8;
26             @ISA = ('Graph::Maker');
27              
28             # uncomment this to run the ### lines
29             # use Smart::Comments;
30              
31              
32             sub _default_graph_maker {
33             require Graph;
34             Graph->new(@_);
35             }
36              
37             sub init {
38             my ($self, %params) = @_;
39              
40             my $N = delete($params{'N'});
41             my $order = delete($params{'order'});
42             my $graph_maker = delete($params{'graph_maker'}) || \&_default_graph_maker;
43              
44             my $graph = $graph_maker->(%params);
45              
46             my $limit;
47             if (! defined $N) {
48             $limit = 2**$order - 1;
49             $graph->set_graph_attribute (name => "Binomial Tree, order $order");
50             } else {
51             $limit = $N-1;
52             if ($N <= 0) {
53             $graph->set_graph_attribute (name => "Binomial Tree, empty");
54             } else {
55             $graph->set_graph_attribute (name => "Binomial Tree, 0 to $limit");
56             }
57             }
58              
59             ### $limit
60             if ($limit >= 0) {
61             $graph->add_vertex(0);
62             my $directed = $graph->is_directed;
63              
64             foreach my $i (1 .. $limit) {
65             my $parent = $i & ~($i ^ ($i-1)); # clear lowest 1-bit
66             ### edge: "$parent down to $i"
67             $graph->add_edge($parent, $i);
68             if ($directed) { $graph->add_edge($i, $parent); }
69             }
70             }
71             return $graph;
72             }
73              
74             Graph::Maker->add_factory_type('binomial_tree' => __PACKAGE__);
75             1;
76              
77             __END__