Solve 'Simple Fun #5: Knapsack Light' kata

Author: borisskert

src/Knapsack.hs

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+module Knapsack (knapsackLight) where
+
+-- https://www.codewars.com/kata/58842a2b4e8efb92b7000080/train/haskell
+
+knapsackLight :: Int -> Int -> Int -> Int -> Int -> Int
+knapsackLight value1 weight1 value2 weight2 maxW
+  | weight1 > maxW && weight2 > maxW = 0
+  | weight1 > maxW = value2
+  | weight2 > maxW = value1
+  | weight1 + weight2 > maxW = max value1 value2
+  | otherwise = value1 + value2

test/KnapsackSpec.hs

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+module KnapsackSpec where
+
+import Knapsack (knapsackLight)
+import Test.HUnit
+import Test.Hspec
+import Text.Printf
+
+spec :: Spec
+spec = do
+  describe "Fixed Tests" $ do
+    it "Basic Cases" $ do
+      fixedTest (10, 5, 6, 4, 8) 10
+      fixedTest (10, 5, 6, 4, 9) 16
+      fixedTest (10, 10, 6, 10, 9) 0
+      fixedTest (10, 2, 11, 3, 1) 0
+      fixedTest (15, 2, 20, 3, 2) 15
+      fixedTest (2, 5, 3, 4, 5) 3
+      fixedTest (4, 3, 3, 4, 4) 4
+      fixedTest (3, 5, 3, 8, 10) 3
+  where
+    fixedTest inp@(v1, w1, v2, w2, mw) exp =
+      assertEqual (showInput inp) exp $
+        knapsackLight v1 w1 v2 w2 mw
+
+showInput :: (Int, Int, Int, Int, Int) -> String
+showInput (a, b, c, d, e) = printf "knapsackLight %d %d %d %d %d" a b c d e