From: Robert Dober <robert.dober@...>
Date: 2007-04-09T03:23:57+09:00
Subject: Re: [QUIZ] Getting to 100 (#119)

Here goes my solution for another nice quiz, yes I know I repeat myself.
It should get all the extras plus one extra from the last quiz, the
fuzzy solutions.

Cheers
Robert
Defaults = { :@fuzz => 0, :@target => 100, :@digits => [*1..9], :@ops
=> [ :-, :- , :+ ] }

### Override the default values if you want ;).
Defaults.each do
  | key, value |
  instance_variable_set "#{key}", value
end # Configurable.each do
### If you are really serious about overriding the default values do it
### again ;).
@ops.map!{|o| " #{o} "}
class Array
  def each_with_rest
    each_with_index do
      | ele, i |
      yield ele, self[0, i] + self[i+1..-1]
    end
  end # each_with_rest
  def runtempatios
    return [[]] if empty?
    remps = []
    each_with_rest do
      | ele, rest |
      remps += rest.runtempatios.map{ | p | p.unshift(ele) }
    end # each_with_rest do
    remps.uniq
  end # def runtempatios
end

# My wife does not like it very much when I am slicing the bread, the
slices are of
# very variable thickness!!!
# A long earned skill that I can eventually put to work now :)
def _slices outer, inner
  ## In order to be able to slice we have to assure that outer.size > inner.size
  return [ outer ] if inner.empty?
  r = []
  (outer.size-inner.size+1).times do
    |i|
    _slices( outer[i+1..-1], inner[1..-1] ).each do
      | slice |
      r <<  outer[0,i.succ] + inner[0..0]  + slice
    end # slices( outer[i+2..-1], rest ).each do
  end # (outer.size-inner.size).times do
  r
end

def slices outer, inner
  _slices( outer, inner ).reject{|s| inner.include? s.last }
end

@count = 0
@total = 0
@target = (@target-@fuzz .. @target+@fuzz)
@ops.runtempatios.each do
  | ops |
  slices( @digits, ops ).each do
    | expression |
    e = expression.join
    value = eval e
    e << " = #{value}"
    if @target === value then
      @count += 1
      puts e.gsub(/./,"*")
      puts e
      puts e.gsub(/./,"*")
    else
      puts e
    end
    @total += 1
  end # slices( @digits, ops ).each do
end # @ops.runtempatios.each do
puts "="*72
puts "There were #{@count} solutions of a total of #{@total} tested"