Adjacency List

1class Node 
2  attr_accessor :data, :next 
3
4  def initialize(data) 
5    @data = data 
6    @next = nil 
7  end
8end 
9
10class AdjList
11  def initialize(v)
12    @graph = []
13    @v = v
14  end
15
16  def add_edge(src, dest)
17    if @graph[src] 
18      @graph[src].append(dest) 
19    elsif @graph[src] == nil 
20      @graph[src] = [dest]
21    end
22
23    if @graph[dest]
24      @graph[dest].append(src)
25    elsif @graph[dest] == nil
26      @graph[dest] = [src]
27    end
28  end
29
30  def display 
31    for i in 0...@v 
32      puts "Adjacency list of vertex #{i}"
33      print "head"
34      temp = @graph[i] 
35      temp.each do |data|
36        print " -> #{data}"
37      end
38      puts
39    end
40  end
41
42end
43
44v = 5
45graph = AdjList.new(v)
46graph.add_edge(0, 1)
47graph.add_edge(0, 4)
48graph.add_edge(1, 2)
49graph.add_edge(1, 3)
50graph.add_edge(1, 4)
51graph.add_edge(2, 3)
52graph.add_edge(3, 4)
53
54graph.display