编辑代码

import java.util.Arrays;
public class FractionalKnapsack {
    static class Fruit implements Comparable<Fruit> {
        String name;
        int weight;
        int value;
        double valuePerKg;
        Fruit(String name, int weight, int value) {
            this.name = name;
            this.weight = weight;
            this.value = value;
            this.valuePerKg = (double) value / weight;
        }
        public int compareTo(Fruit other) {
            return Double.compare(other.valuePerKg, this.valuePerKg);
        }
    }
    public static void fillKnapsack(Fruit[] fruits, int capacity) {
        Arrays.sort(fruits);
        int currentWeight = 0;
        double totalValue = 0;
        for (Fruit fruit : fruits) {
            if (currentWeight + fruit.weight <= capacity) {
                currentWeight += fruit.weight;
                totalValue += fruit.value;
                System.out.println("装100%" + fruit.name);
            } else {
                double fraction = (double) (capacity - currentWeight) / fruit.weight;
                totalValue += fraction * fruit.value;
                System.out.printf("装%.2f%%%s\n", fraction * 100, fruit.name);
                break;
            }
        }
        System.out.println("总价值: " + totalValue);
    }
    public static void main(String[] args) {
        Fruit[] fruits = {
            new Fruit("苹果", 15, 300),
            new Fruit("香蕉", 18, 180),
            new Fruit("橘子", 10, 150),
            new Fruit("猕猴桃", 9, 270)
        };
        fillKnapsack(fruits, 20);
    }
}