Data commit

Task/Knapsack-problem-Unbounded/Go/knapsack-problem-unbounded.go

@@ -0,0 +1,66 @@
+package main
+
+import "fmt"
+
+type Item struct {
+	Name           string
+	Value          int
+	Weight, Volume float64
+}
+
+type Result struct {
+	Counts []int
+	Sum    int
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func Knapsack(items []Item, weight, volume float64) (best Result) {
+	if len(items) == 0 {
+		return
+	}
+	n := len(items) - 1
+	maxCount := min(int(weight/items[n].Weight), int(volume/items[n].Volume))
+	for count := 0; count <= maxCount; count++ {
+		sol := Knapsack(items[:n],
+			weight-float64(count)*items[n].Weight,
+			volume-float64(count)*items[n].Volume)
+		sol.Sum += items[n].Value * count
+		if sol.Sum > best.Sum {
+			sol.Counts = append(sol.Counts, count)
+			best = sol
+		}
+	}
+	return
+}
+
+func main() {
+	items := []Item{
+		{"Panacea", 3000, 0.3, 0.025},
+		{"Ichor", 1800, 0.2, 0.015},
+		{"Gold", 2500, 2.0, 0.002},
+	}
+	var sumCount, sumValue int
+	var sumWeight, sumVolume float64
+
+	result := Knapsack(items, 25, 0.25)
+
+	for i := range result.Counts {
+		fmt.Printf("%-8s x%3d  -> Weight: %4.1f  Volume: %5.3f  Value: %6d\n",
+			items[i].Name, result.Counts[i], items[i].Weight*float64(result.Counts[i]),
+			items[i].Volume*float64(result.Counts[i]), items[i].Value*result.Counts[i])
+
+		sumCount += result.Counts[i]
+		sumValue += items[i].Value * result.Counts[i]
+		sumWeight += items[i].Weight * float64(result.Counts[i])
+		sumVolume += items[i].Volume * float64(result.Counts[i])
+	}
+
+	fmt.Printf("TOTAL (%3d items) Weight: %4.1f  Volume: %5.3f  Value: %6d\n",
+		sumCount, sumWeight, sumVolume, sumValue)
+}