编辑代码

import java.util.*;


public class Backpack {
    public static void main(String[] args) {
        List<Fruit> fruits = new ArrayList<>();
        fruits.add(new Fruit("苹果", 15, 300));
        fruits.add(new Fruit("香蕉", 18, 180));
        fruits.add(new Fruit("橘子", 10, 150));
        fruits.add(new Fruit("猕猴桃", 9, 270));

        Collections.sort(fruits, new Comparator<Fruit>() {
            @Override
            public int compare(Fruit f1, Fruit f2) {
                double v1 = f1.value / f1.weight;
                double v2 = f2.value / f2.weight;
                if (v1 > v2) {
                    return -1;
                } else {
                    return 1;
                }
            }
        });

        double capacity = 20; // 背包的承重
        double totalWeight = 0;
        double totalValue = 0;

        for (Fruit fruit : fruits) {
            if (totalWeight + fruit.weight <= capacity) {
                totalWeight += fruit.weight;
                totalValue += fruit.value;
                System.out.println("装入" + fruit.name + "，重量：" + fruit.weight + "kg，价值：" + fruit.value + "元");
            } else {
                double remain = capacity - totalWeight;
                totalWeight += remain;
                totalValue += (remain / fruit.weight) * fruit.value;
                System.out.println("装入部分" + fruit.name + "，重量：" + remain + "kg，价值：" + (remain / fruit.weight) * fruit.value + "元");
                break;
            }
        }

        System.out.println("背包中装入的水果总重量为：" + totalWeight + "kg");
        System.out.println("背包中装入的水果总价值为：" + totalValue + "元");
    }
}

class Fruit {
    String name;
    double weight;
    double value;

    public Fruit(String name, double weight, double value) {
        this.name = name;
        this.weight = weight;
        this.value = value;
    }
}