```=begin
> The quiz, then, is to solve this problem without thinking, instead
> letting the computer think for you.

I did not intent to seriously submit this solution, but it can be
helpful as an example of how to use Ruby to solve a problem quickly
without thinking too much or locating Knuth on the bookshelve.
Writing this code took maybe ten minutes and happened step-by-step
with checking the immediate results.

Since there are only 168 solutions (254 if you allow a sign before the
first digit), brute-forcing is the simplest thing one can do.
the digits onto further operations.  (Different digit order is not
that easy to implement and maybe be futile to do with brute-forcing.)
=end

(00000000..'22222222'.to_i(3)).map { |x| x.to_s(3).rjust(8, "0").
tr('012', '-+ ') }.
find_all { |x| x.count("-") == 2 and x.count("+") == 1 }.
map { |x|
t = "1" + x.split(//).zip((2..9).to_a).join.delete(" ")
[eval(t), t]
}.sort.each { |s, x|
puts "*****************" if s == 100
puts "#{x}: #{s}"
puts "*****************" if s == 100
}

__END__

2#787<p4>lilith:~/mess/current\$ ruby quiz119.rb |grep -C4 100\$
123-456-7+89: -251
123+45-67-89: 12
123-45+67-89: 56
*****************
123-45-67+89: 100
*****************
12+345-67-89: 201
1-234+567-89: 245
1-23-456+789: 311

--
Christian Neukirchen  <chneukirchen / gmail.com>  http://chneukirchen.org

```