Class: Djikstra::Cli

Inherits:
Object
  • Object
show all
Defined in:
lib/djikstra/cli.rb

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Cli

Returns a new instance of Cli.



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# File 'lib/djikstra/cli.rb', line 3

def initialize(*args)
  @file  = args[0]
  @start = args[1].to_s.upcase
  @stop  = args[2].to_s.upcase
end

Instance Method Details

#parse ⇒ Object 



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# File 'lib/djikstra/cli.rb', line 26

def parse
  edges = []
  open(@file) do |f|
    f.readlines.each_with_index do |line,idx|
      items = line.split /\[(\w+),(\w+),(\d+)\]/
      
      # only care about the center matches
      edges.push [items[1],items[2],items[3],idx+1]
    end
  end
  edges
end

#run ⇒ Object 



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# File 'lib/djikstra/cli.rb', line 39

def run
  return usage unless @file && @start && @stop
  
  graph = Graph.new(parse)
  path  = graph.shortest_path_between(@start,@stop)
  dist  = graph.shortest_path_distance
  
  puts "Shortest path is [#{path.join(',')}] with a total cost of #{dist}"
rescue ParseError, GraphError => e
  puts e.to_s
  exit 1
end

#usage ⇒ Object 



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# File 'lib/djikstra/cli.rb', line 9

def usage
  puts "#{$0} <file> <start> <end>"
  puts "  file  - a DAG graph file"
  puts "  start - the name of starting node"
  puts "  end   - the name of the ending node"
  puts
  puts " DAG graph file contains lines (between two nodes) and weights in the following format"
  puts "     [A,B,1]"
  puts "     [B,C,3]"
  puts
  puts "Example:"
  puts " $ #{$0} graph.txt A C"
  puts " Shortest path is [A,B,C] with total cost 4"
  
  exit 1
end