编辑代码

import java.util.Arrays;
import java.util.Comparator;
import java.util.LinkedList;

public class Fruit {
        public static void main(String[] args) {
        // 在main方法中调用test方法
        test();
    }

    public static LinkedList<Item> packFruit(int packCapacity, Item[] items){
         LinkedList<Item> fruitPacking = new LinkedList<Item>(); // 记录需要装包的豆子
         //1. 按照单价从高到低进行排序
         Arrays.sort(items,new Comparator<Item>() {
             public int compare(Item left,Item right){
                 double leftUnitPrice = left.totalValue/left.totalWeight;
                 double rightUnitPrice = right.totalValue/right.totalWeight;
                 if (leftUnitPrice > rightUnitPrice){
                     return -1;
                 }
                 else if (leftUnitPrice == rightUnitPrice) {
                     return 0;
                 }
                 else {
                     return 1;
                 }
             }
             
         });

         //2. 单价从高到低依次取出豆子
         
  int leftPackCapacity = packCapacity;
         for (int i = 0; i < items.length; ++i) {
             if (leftPackCapacity > items[i].totalWeight) {
                 leftPackCapacity -= items[i].totalWeight;
                 fruitPacking.add(new Item(items[i]));
             }
             else {
                 double unitPrice = items[i].totalValue/items[i].totalWeight;
                 double packWeight = leftPackCapacity;
                 double packValue = packWeight * unitPrice;
                 fruitPacking.add(new Item(items[i].name, packWeight, packValue));
                 leftPackCapacity = 0;
                 break;
             }
         }

         return fruitPacking;
    }
    public static void test() {
        Item[] items = {
                new Item("苹果", 15, 300),
                new Item("香蕉", 18, 180),
                new Item("橘子", 10, 150),
                new Item("猕猴桃", 9, 270)
        };

        LinkedList<Item> fruits = packFruit(20, items);

        double maxValue = 0;

        System.out.println("装了如下物品：");
        for (int i = 0; i < fruits.size(); ++i) {
            maxValue += fruits.get(i).totalValue;
            System.out.println(fruits.get(i).name + " " + fruits.get(i).totalWeight);
        }

        System.out.println("总价值：" + maxValue);

	}

}

class Item {
    public String name;
    public double totalWeight;
    public double totalValue;

    Item(String itemName, double weight, double value) {
        this.name = itemName;
        this.totalWeight = weight;
        this.totalValue = value;
    }

     Item(Item item) {
        this.name = item.name;
        this.totalWeight = item.totalWeight;
        this.totalValue = item.totalValue;
    }
}