编辑代码

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


public class GreedyTemplate {


static 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;
    }
}



    public static LinkedList<Item> packFruit(int packCapacity, Item[] items){
         LinkedList<Item> fruits = new LinkedList<Item>(); // 记录需要装包的水果

         //1. 按照单价从高到低进行排序         
             Arrays.sort(items,new Comparator<Item>() {   
                 @Override
                 public int compare(Item left, Item right) {
                     double leftUniPrice =left.totalValue/left.totalWeight;
                     double rightUniPrice= right.totalValue/right.totalWeight;
                     if(leftUniPrice>rightUniPrice){
                         return -1;
                     }else if(leftUniPrice==rightUniPrice){
                         return 0;
                     }else{
                         return 1;
                     }
                 }
         });
         
         int leftPackCapacity=packCapacity;

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


         return fruits;
    }
    public static void main(String[] args) {
        Item[] items = {
            new Item("Apple", 15, 300),
            new Item("Banana", 18, 180),
            new Item("Orange", 10, 150),
            new Item("Kiwi ", 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);

	}

}