A-M baby

Task/Knapsack-problem-0-1/Clojure/knapsack-problem-0-1-1.clj

@@ -0,0 +1,27 @@
+(def item-data
+  [ "map"         9 150
+    "compass"    13  35
+    "water"     153 200
+    "sandwich"   50 160
+    "glucose"    15  60
+    "tin"        68  45
+    "banana"     27  60
+    "apple"      39  40
+    "cheese"     23  30
+    "beer"       52  10
+    "suntan cream"   11  70
+    "camera"     32  30
+    "t-shirt"    24  15
+    "trousers"   48  10
+    "umbrella"   73  40
+    "waterproof trousers"    42  70
+    "waterproof overclothes" 43  75
+    "note-case"  22  80
+    "sunglasses"  7  20
+    "towel"      18  12
+    "socks"       4  50
+    "book"       30  10])
+
+(defstruct item :name :weight :value)
+
+(def items (vec (map #(apply struct item %) (partition 3 item-data))))

Task/Knapsack-problem-0-1/Clojure/knapsack-problem-0-1-2.clj

@@ -0,0 +1,17 @@
+(declare mm) ;forward decl for memoization function
+
+(defn m [i w]
+  (cond
+    (< i 0) [0 []]
+    (= w 0) [0 []]
+    :else
+    (let [{wi :weight vi :value} (get items i)]
+      (if (> wi w)
+        (mm (dec i) w)
+        (let [[vn sn :as no]  (mm (dec i) w)
+              [vy sy :as yes] (mm (dec i) (- w wi))]
+          (if (> (+ vy vi) vn)
+            [(+ vy vi) (conj sy i)]
+            no))))))
+
+(def mm (memoize m))

Task/Knapsack-problem-0-1/Clojure/knapsack-problem-0-1-3.clj

@@ -0,0 +1,7 @@
+(use '[clojure.string :only [join]])
+
+(let [[value indexes] (m (-> items count dec) 400)
+      names (map (comp :name items) indexes)]
+  (println "items to pack:" (join ", " names))
+  (println "total value:" value)
+  (println "total weight:" (reduce + (map (comp :weight items) indexes))))