module Syzygies

# File lib/syzygies.rb, line 19
def Syzygies.depthLimitedSearch(start, goal, depth)
        start = Word.new(start)
        goal = Word.new(goal)
        raise "#{start.word} is not in Wordlist" unless Syzygies::Wordlist.instance.list.include? start
        raise "#{goal.word} is not in Wordlist" unless Syzygies::Wordlist.instance.list.include? goal

        return self.recursiveDLS(start, start, goal, depth)
end

# File lib/syzygies.rb, line 12
def Syzygies.iterativeDeepeningSearch(start, goal)
        ( 1..Wordlist.instance.list.length ).each do |i|
                result = depthLimitedSearch(start, goal, i)
                return result unless result == 'cutoff'
        end
end

# File lib/syzygies.rb, line 28
def Syzygies.recursiveDLS(node, start, goal, limit)
        cutoff_occured = nil
        if node == goal
                return node
        elsif limit == 0
                return 'cutoff'
        else
                Wordlist.instance.get(node).shuffle.each do |w|
                        child = w.addParent(node)
                        result = recursiveDLS(child, start, goal, limit - 1)
                        cutoff_occured = ( result == 'cutoff' )
                        return result unless result == 'failure' || result == 'cutoff'
                end
                if cutoff_occured then return 'cutoff' else return "failure" end
        end
end