大致就是完善一个购物车,结算购物车金额的题,极其简单,但是我测试用例只过了50%代码如下,哪个大佬能帮忙看看问题import java.math.BigDecimal;import java.math.RoundingMode;import java.util.*;class Solution {// 购物车集合public Map<Product, Integer> cart;public Solution() {cart = new HashMap<>();}public void addProductToCart(Product product, int quantity) {cart.put(product,cart.getOrDefault(product,0)+quantity);}public void removeProduct(Product product) {cart.remove(product);}public String getTotalAmount() {BigDecimal amount =BigDecimal.ZERO;for (Map.Entry<Product, Integer> entry : cart.entrySet()) {String price = entry.getKey().getPrice();Integer quantity = entry.getValue();BigDecimal priceVal = new BigDecimal(price);BigDecimal temp = priceVal.multiply(new BigDecimal(quantity)).setScale(2,RoundingMode.HALF_UP);amount = amount.add(temp);}String totalamount = String.valueOf(amount);return totalamount;}}class Product {private String id;private String name;private String price;public Product(String id, String name, String price) {this.id = id;this.name = name;this.price = price;}public String getId() {return id;}public String getName() {return name;}public String getPrice() {return price;}public static void main(String[] args) {Product product=new Product("1","测试","2");Product product2=new Product("2","测试","2");Solution solution=new Solution();solution.addProductToCart(product,5);solution.addProductToCart(product,2);solution.addProductToCart(product2,1);System.out.println(solution.cart);System.out.println(solution.getTotalAmount());}}