Class: DS::Graph

Inherits:
Object
  • Object
show all
Defined in:
lib/ds/graphs/graph.rb

Direct Known Subclasses

Digraph

Constant Summary collapse

Infinity = 
1 << 64

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(edges, store = :list) ⇒ Graph

Create new graph from array of edges. Second parameter determines graph internal implementation: :list (Adjency List), :tri_matrix (Triangular Matrix), :matrix (Matrix).



9
10
11
12
13
14
15
16
17
18
 
# File 'lib/ds/graphs/graph.rb', line 9

def initialize(edges,store = :list)
  case store
  when :matrix
    @g = GraphAsMatrix.new(edges)
  when :tri_matrix
    @g = GraphAsTriMatrix.new(edges)
  else
    @g = GraphAsList.new(edges)
  end
end

Class Method Details

.create(edges) ⇒ Object

Create new graph from array of edges. Internally graph will be represented by Triangular Matrix.



22
23
24
 
# File 'lib/ds/graphs/graph.rb', line 22

def self.create(edges)
  new(edges,:tri_matrix) 
end

Instance Method Details

#add(x, y) ⇒ Object 



26
27
28
 
# File 'lib/ds/graphs/graph.rb', line 26

def add(x,y)
  @g.add(x,y)
end

#add_edges(edges) ⇒ Object 



81
82
83
 
# File 'lib/ds/graphs/graph.rb', line 81

def add_edges(edges)
  @g.add_edges(edges)
end

#bfs(s) ⇒ Object 



46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
 
# File 'lib/ds/graphs/graph.rb', line 46

def bfs s
  colors = {}
  parents =  {}
  res = []
  d = {}
  q = Queue.new

  @g.each_vertex do |v|
    colors[v] = :white
    parents[v] = nil
    d[v] = Infinity
  end

  colors[s] = :white
  parents[s] = nil
  d[s] = 0

  q.enqueue s

  while !q.empty?
    u = q.dequeue 
    @g.neighbors(u).each do |v|
      if colors[v] === :white
        colors[v] = :grey
        d[v] = d[u] + 1
        parents[v] = u
        q.enqueue v
      end
    end
    colors[u] = :black
    res << u
  end
  res
end

#degree(x) ⇒ Object

Returns vertex degree. Second parameter determines direction - :in incoming edges, :out - outcoming edges, :all - incoming and outcoming edges.



87
88
89
 
# File 'lib/ds/graphs/graph.rb', line 87

def degree x
  @g.degree x
end

#each_edge(&block) ⇒ Object 



38
39
40
 
# File 'lib/ds/graphs/graph.rb', line 38

def each_edge &block
  @g.each_edge &block
end

#each_vertex(&block) ⇒ Object 



34
35
36
 
# File 'lib/ds/graphs/graph.rb', line 34

def each_vertex &block
  @g.each_vertex &block
end

#edge?(x, y) ⇒ Boolean

Returns:

  • (Boolean) 


91
92
93
 
# File 'lib/ds/graphs/graph.rb', line 91

def edge? x,y
  @g.edge? x,y
end

#edge_size ⇒ Object 



103
104
105
 
# File 'lib/ds/graphs/graph.rb', line 103

def edge_size
  @g.vmax+1
end

#get_edge(x, y) ⇒ Object 



95
96
97
 
# File 'lib/ds/graphs/graph.rb', line 95

def get_edge x, y
  @g.get_edge x,y
end

#neighbors(v) ⇒ Object 



42
43
44
 
# File 'lib/ds/graphs/graph.rb', line 42

def neighbors v
  @g.neighbors v
end

#remove(x, y) ⇒ Object 



30
31
32
 
# File 'lib/ds/graphs/graph.rb', line 30

def remove(x,y)
  @g.remove(x,y) 
end

#vertex_size ⇒ Object 



99
100
101
 
# File 'lib/ds/graphs/graph.rb', line 99

def vertex_size
  @g.vertex_size
end