;Task: Find solutions to the   ''sum to one hundred''   puzzle. Add (insert) the mathematical operators     '''+'''   or   '''-'''     (plus or minus)   before any of the digits in the
decimal numeric string   '''123456789'''   such that the resulting mathematical expression adds up to a
particular sum   (in this iconic case,   '''100'''). Example: 123 + 4 - 5 + 67 - 89 = 100 Show all output here. :*   Show all solutions that sum to   '''100''' :*   Show the sum that has the maximum   ''number''   of solutions   (from zero to infinity) :*   Show the lowest positive sum that   ''can't''   be expressed   (has no solutions),   using the rules for this task :*   Show the ten highest numbers that can be expressed using the rules for this task   (extra credit)
  (where   ''infinity''   would be a relatively small   123,456,789) An example of a sum that can't be expressed   (within the rules of this task)   is:   '''5074'''
(which,   of course,   isn't the lowest positive sum that can't be expressed).