September 2017 Update

Task/Knapsack-problem-Bounded/Kotlin/knapsack-problem-bounded.kotlin

@@ -0,0 +1,82 @@
+// version 1.1.2
+
+data class Item(val name: String, val weight: Int, val value: Int, val count: Int)
+
+val items = listOf(
+    Item("map", 9, 150, 1),
+    Item("compass", 13, 35, 1),
+    Item("water", 153, 200, 2),
+    Item("sandwich", 50, 60, 2),
+    Item("glucose", 15, 60, 2),
+    Item("tin", 68, 45, 3),
+    Item("banana", 27, 60, 3),
+    Item("apple", 39, 40, 3),
+    Item("cheese", 23, 30, 1),
+    Item("beer", 52, 10, 3),
+    Item("suntan cream", 11, 70, 1),
+    Item("camera", 32, 30, 1),
+    Item("T-shirt", 24, 15, 2),
+    Item("trousers", 48, 10, 2),
+    Item("umbrella", 73, 40, 1),
+    Item("waterproof trousers", 42, 70, 1),
+    Item("waterproof overclothes", 43, 75, 1),
+    Item("note-case", 22, 80, 1),
+    Item("sunglasses", 7, 20, 1),
+    Item("towel", 18, 12, 2),
+    Item("socks", 4, 50, 1),
+    Item("book", 30, 10, 2)
+)
+
+val n = items.size
+
+const val MAX_WEIGHT = 400
+
+fun knapsack(w: Int): IntArray {
+    val m  = Array(n + 1) { IntArray(w + 1) }
+    for (i in 1..n) {
+        for (j in 0..w) {
+            m[i][j] = m[i - 1][j]
+            for (k in 1..items[i - 1].count) {
+                if (k * items[i - 1].weight > j) break
+                val v = m[i - 1][j - k * items[i - 1].weight] + k * items[i - 1].value
+                if (v > m[i][j]) m[i][j] = v
+            }
+        }
+    }
+    val s = IntArray(n)
+    var j = w
+    for (i in n downTo 1) {
+        val v = m[i][j]
+        var k = 0
+        while (v != m[i - 1][j] + k * items[i - 1].value) {
+            s[i - 1]++
+            j -= items[i - 1].weight
+            k++
+        }
+    }
+    return s
+}
+
+fun main(args: Array<String>) {
+   val s = knapsack(MAX_WEIGHT)
+   println("Item Chosen             Weight Value  Number")
+   println("---------------------   ------ -----  ------")
+   var itemCount = 0
+   var sumWeight = 0
+   var sumValue  = 0
+   var sumNumber = 0
+   for (i in 0 until n) {
+       if (s[i] == 0) continue
+       itemCount++
+       val name   = items[i].name
+       val number = s[i]
+       val weight = items[i].weight * number
+       val value  = items[i].value  * number
+       sumNumber += number
+       sumWeight += weight
+       sumValue  += value
+       println("${name.padEnd(22)}    ${"%3d".format(weight)}   ${"%4d".format(value)}    ${"%2d".format(number)}")
+   }
+   println("---------------------   ------ -----  ------")
+   println("Items chosen $itemCount           ${"%3d".format(sumWeight)}   ${"%4d".format(sumValue)}    ${"%2d".format(sumNumber)}")
+}