limp-xkcd.hs

-- Solve for the maximum/minimum number of menu items adding up to $15.05
-- http://xkcd.com/287/
xkcd :: Direction -> Program String String IntDouble
xkcd dir = program dir
           ( z1 mf .+.
             z1 ff .+.
             z1 ss .+.
             z1 hw .+.
             z1 ms .+.
             z1 sp )
           ( z mf mfp .+.
             z ff ffp .+.
             z ss ssp .+.
             z hw hwp .+.
             z ms msp .+.
             z sp spp :== con 1505 )
           [ lowerZ 0 mf
           , lowerZ 0 ff
           , lowerZ 0 ss
           , lowerZ 0 hw
           , lowerZ 0 ms
           , lowerZ 0 sp
           ]
  where
    (mf, mfp) = ("mixed-fruit",       215)
    (ff, ffp) = ("french-fries",      275)
    (ss, ssp) = ("side-salad",        335)
    (hw, hwp) = ("hot-wings",         355)
    (ms, msp) = ("mozzarella-sticks", 420)
    (sp, spp) = ("sampler-plate",     580)