knapsack.clj

(def items [[1 2] [2 4] [3 6] [10 5]])

(defn values [] (into [] ((fn [items] (for [i items] {:weight (first i) :value (last i)}))items)))


(defn knapsack [weight values]
  (if
    (empty? values) 0                                       ;; base case
                    (if (> (:weight (first values)) weight) 
                      (knapsack weight (rest values))       ;; continue
                      (max 
                        (+ (:value (first values)) (knapsack (- weight (:weight (first values))) (rest values)))
                        (knapsack weight (rest values)))))) ;; compare branches

(knapsack 12 (values))