----------------------------------------------------------------------------- -- | -- Module : Documentation.SBV.Examples.Puzzles.DogCatMouse -- Copyright : (c) Levent Erkok -- License : BSD3 -- Maintainer: erkokl@gmail.com -- Stability : experimental -- -- Puzzle: -- Spend exactly 100 dollars and buy exactly 100 animals. -- Dogs cost 15 dollars, cats cost 1 dollar, and mice cost 25 cents each. -- You have to buy at least one of each. -- How many of each should you buy? ----------------------------------------------------------------------------- module Documentation.SBV.Examples.Puzzles.DogCatMouse where import Data.SBV -- | Prints the only solution: -- -- >>> puzzle -- Solution #1: -- dog = 3 :: Integer -- cat = 41 :: Integer -- mouse = 56 :: Integer -- This is the only solution. puzzle :: IO AllSatResult puzzle = allSat \$ do [dog, cat, mouse] <- sIntegers ["dog", "cat", "mouse"] solve [ dog .>= 1 -- at least one dog , cat .>= 1 -- at least one cat , mouse .>= 1 -- at least one mouse , dog + cat + mouse .== 100 -- buy precisely 100 animals , 15 `per` dog + 1 `per` cat + 0.25 `per` mouse .== 100 -- spend exactly 100 dollars ] where p `per` q = p * (sFromIntegral q :: SReal)