RosettaCodeData/Task/Knapsack-problem-Continuous/Clojure/knapsack-problem-continuous...

25 lines
940 B
Clojure

(def items
[{:name "beef" :weight 3.8 :price 36}
{:name "pork" :weight 5.4 :price 43}
{:name "ham" :weight 3.6 :price 90}
{:name "graves" :weight 2.4 :price 45}
{:name "flitch" :weight 4.0 :price 30}
{:name "brawn" :weight 2.5 :price 56}
{:name "welt" :weight 3.7 :price 67}
{:name "salami" :weight 3.0 :price 95}
{:name "sausage" :weight 5.9 :price 98}])
(defn per-kg [item] (/ (:price item) (:weight item)))
(defn rob [items capacity]
(let [best-items (reverse (sort-by per-kg items))]
(loop [items best-items cap capacity total 0]
(let [item (first items)]
(if (< (:weight item) cap)
(do (println (str "Take all " (:name item)))
(recur (rest items) (- cap (:weight item)) (+ total (:price item))))
(println (format "Take %.1f kg of %s\nTotal: %.2f monies"
cap (:name item) (+ total (* cap (per-kg item))))))))))
(rob items 15)