用Java实现以下问题 最好用算法来实现？

Question

用java实现以下场景，有100条商品，每个商品的价格0到1000元不等
商品数据:

{ id: 1, productName: '特价商品1', price: 200 },
{ id: 2, productName: '特价商品2', price: 400 },
{ id: 3, productName: '特价商品3', price: 600 },
{ id: 4, productName: '特价商品4', price: 800 },

例如200元 加价之后就是240元 利润是40元

首先把0到300元的商品的加价30%，301到500的加价20%，501到1000元商品的加价10%，
然后0到300元的商品订单有300条，301-500的商品订单有400条，501-1000的商品订单有300条，
最后计算他的总利润有多少，最好写出算法

Answer 1

只计算总利润，那么关注每个元素的 price 即可。以下是一段伪代码示意：

CALC(A)
    R = 0
    N = A.length
    for i in 0..N
        P = A[i].price
        if P <= 300
            R += P * 0.3
        else if P <= 500
            R += P * 0.2
        else 
            R += P * 0.1
    return R

若是计算的同时又需要修改，则可以加上这些：

CALC(A)
    R = 0
    N = A.length
    for i in 0..N
        P = A[i].price
        if P <= 300
            R += P * 0.3
+           A[i].price *= 1.3
        else if P <= 500
            R += P * 0.2
+           A[i].price *= 1.2
        else 
            R += P * 0.1
+           A[i].price *= 1.1;
    return R

Answer 2

你确定这不是什么JAVA课的编程小作业吗..

import java.util.ArrayList;
import java.util.List;

class Product {
    private int id;
    private String productName;
    private double price;

    public Product(int id, String productName, double price) {
        this.id = id;
        this.productName = productName;
        this.price = price;
    }

    public double calculateProfit() {
        double profit = 0;
        if (price <= 300) {
            profit = price * 0.3;
        } else if (price <= 500) {
            profit = price * 0.2;
        } else if (price <= 1000) {
            profit = price * 0.1;
        }
        return profit;
    }
}

public class Main {
    public static void main(String[] args) {
        List<Product> products = new ArrayList<>();
        products.add(new Product(1, "特价商品1", 200));
        products.add(new Product(2, "特价商品2", 400));
        products.add(new Product(3, "特价商品3", 600));
        products.add(new Product(4, "特价商品4", 800));

        int orderCount1 = 300;
        int orderCount2 = 400;
        int orderCount3 = 300;

        double totalProfit = 0;
        for (Product product : products) {
            double profit = product.calculateProfit();
            if (product.getPrice() <= 300) {
                totalProfit += profit * orderCount1;
            } else if (product.getPrice() <= 500) {
                totalProfit += profit * orderCount2;
            } else if (product.getPrice() <= 1000) {
                totalProfit += profit * orderCount3;
            }
        }

        System.out.println("总利润：" + totalProfit);
    }
}

Answer 3

大概思路是，在 calculateTotalProfit 中，遍历所有商品，并根据价格范围确定对应的利润百分比（30%、20%、或10%）。然后，根据商品的价格和利润百分比计算单个商品的利润，并累加到 totalProfit 变量中。运行最后的时候，返回计算得到的总利润。代码比较简单，注释差不多都解释了，所以不做过多赘述。

import java.util.ArrayList;
import java.util.List;

class Product {
    int id;
    String productName;
    int price;

    public Product(int id, String productName, int price) {
        this.id = id;
        this.productName = productName;
        this.price = price;
    }
}

public class ProfitCalculator {
    public static void main(String[] args) {
        List<Product> products = new ArrayList<>();
        // 添加100条商品数据
        // 例如：products.add(new Product(1, "特价商品1", 200));
        //      products.add(new Product(2, "特价商品2", 400));
        // ...

        int totalProfit = calculateTotalProfit(products);
        System.out.println("总利润为：" + totalProfit + "元");
    }

    public static int calculateTotalProfit(List<Product> products) {
        int totalProfit = 0;
        for (Product product : products) {
            int price = product.price;
            int profitPercentage;
            // 根据价格范围确定利润百分比
            if (price <= 300) {
                profitPercentage = 30;
            } else if (price <= 500) {
                profitPercentage = 20;
            } else {
                profitPercentage = 10;
            }

            // 计算单个商品的利润
            int profit = price * profitPercentage / 100;
            totalProfit += profit;
        }
        return totalProfit;
    }
}

Answer 4

import java.util.ArrayList;
import java.util.List;

class Product {
    int id;
    String productName;
    double price;
    double profit;

    public Product(int id, String productName, double price) {
        this.id = id;
        this.productName = productName;
        this.price = price;
        this.profit = 0;
    }

    public void applyMarkup(double percentage) {
        double markup = this.price * percentage;
        this.profit = markup;
        this.price += markup;
    }
}

public class ProfitCalculator {
    public static void main(String[] args) {
        List<Product> products = new ArrayList<>();

        // 假设这里已经填充了100条商品数据
        for (int i = 1; i <= 100; i++) {
            products.add(new Product(i, "特价商品" + i, (i * 10) % 1001));
        }

        int orderCount1 = 300; // 0-300元的订单数量
        int orderCount2 = 400; // 301-500元的订单数量
        int orderCount3 = 300; // 501-1000元的订单数量

        double totalProfit = 0;

        for (Product product : products) {
            if (product.price <= 300) {
                product.applyMarkup(0.3);
                totalProfit += product.profit * orderCount1;
            } else if (product.price <= 500) {
                product.applyMarkup(0.2);
                totalProfit += product.profit * orderCount2;
            } else if (product.price <= 1000) {
                product.applyMarkup(0.1);
                totalProfit += product.profit * orderCount3;
            }
        }

        System.out.println("总利润为: " + totalProfit + "元");
    }
}

Answer 5

import java.util.ArrayList;
import java.util.List;

class Product {
    private int id;
    private String productName;
    private int price;

    public Product(int id, String productName, int price) {
        this.id = id;
        this.productName = productName;
        this.price = price;
    }

    public int getId() {
        return id;
    }

    public String getProductName() {
        return productName;
    }

    public int getPrice() {
        return price;
    }
}

public class Main {
    public static void main(String[] args) {
        List<Product> products = new ArrayList<>();
        products.add(new Product(1, "特价商品1", 200));
        products.add(new Product(2, "特价商品2", 400));
        products.add(new Product(3, "特价商品3", 600));
        products.add(new Product(4, "特价商品4", 800));

        int totalProfit = calculateTotalProfit(products);
        System.out.println("总利润：" + totalProfit + "元");
    }

    public static int calculateTotalProfit(List<Product> products) {
        int totalProfit = 0;

        for (Product product : products) {
            int price = product.getPrice();
            int profit;

            if (price <= 300) {
                profit = (int) (price * 0.3);
            } else if (price <= 500) {
                profit = (int) (price * 0.2);
            } else {
                profit = (int) (price * 0.1);
            }

            totalProfit += profit;
        }

        return totalProfit;
    }
}

用java写的。