原题

https://pintia.cn/problem-sets/994805260223102976/problems/994805301562163200

代码

java代码超时，c代码通过（c解法点击跳转）

循环+每次把最大值遍历比较出来（较费时）

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int N = scanner.nextInt();
        int D = scanner.nextInt();
        float profit=0;
        float  stock[]=new float[1000],prices[]=new float[1000];
        for (int i=0;i<N;i++) stock[i]=scanner.nextFloat();
        for (int i=0;i<N;i++) prices[i]=scanner.nextFloat();

        while (D>0){
            int max=0;
            for (int i=0;i<N;i++){
                if ((prices[i]/stock[i])>(prices[max]/stock[max])){
                    max=i;
                }
            }
            if (D>stock[max]){
                profit+=prices[max];
                D-=stock[max];
                prices[max]=0;//把最大的单价的位置清零，下一轮不会选到它为最大值
            }else {
                profit+=D*prices[max]/stock[max];//注意这里的+号，最后一次比较
                D=0;
            }
        }
        System.out.printf("%.2f",profit);
    }
}

先排序+再填入。使用类来存储各种类的月饼（c用结构体）

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int N = scanner.nextInt();
        int D = scanner.nextInt();
        float protit=0;
        ArrayList<MoonCake> list = new ArrayList<>();

        for (int i=0;i<N;i++) {//填入库存
            MoonCake moonCake = new MoonCake();
            moonCake.setStock(scanner.nextFloat());
            list.add(moonCake);
        }
        for (int i=0;i<N;i++) {//填入总价与计算单价
            list.get(i).setPrice(scanner.nextFloat());
            list.get(i).setUnitPrice(list.get(i).getPrice()/list.get(i).getStock());
        }
        Collections.sort(list);//排序

        for (int i=0;i<N;i++){//按顺序填入
            if (list.get(i).getStock()<D){//小于库存
                protit+=list.get(i).getStock()*list.get(i).getUnitPrice();
                D-=list.get(i).getStock();
            }else {
                protit+=D*list.get(i).getUnitPrice();//最后一次
                break;
            }
        }
        System.out.printf("%.2f",protit);
    }
}
class MoonCake implements Comparable<MoonCake>{
    private float stock;
    private float price;
    private float unitPrice;

    @Override
    public int compareTo(MoonCake o) {
        return -Double.compare(unitPrice,o.unitPrice);//按从大到小逆向排序
    }

    public float getStock() {
        return stock;
    }

    public void setStock(float stock) {
        this.stock = stock;
    }

    public float getPrice() {
        return price;
    }

    public void setPrice(float price) {
        this.price = price;
    }

    public float getUnitPrice() {
        return unitPrice;
    }

    public void setUnitPrice(float unitPrice) {
        this.unitPrice = unitPrice;
    }
}