(1)定义一个苹果类型，具有品牌,重量和甜度三个属性，以及必要的成员函数； (2)主函数main()使用STL算法和lambda表达式，筛选出符合条件（比如某个品牌，或是重量大于50克且甜度大于9）的苹果。 输入格式: 见输入样例。 输出格式: 见输出样例。 输入样例: 第一行输入苹果数量n 然后每行输入一个苹果，共n行； 然后输入要筛选的品牌；示例中是HFS； 然后输入高品质苹果的条件：重量和甜度，示例中是重量大于50.0, 甜度大于9.0； 6 XJ 50.8 9.2 XJ 60.5 10.2 HFS 50.2 10.5 HFS 55.8 10.9 TX 45.8 9.5 TX 40.0 8.5 HFS 50.0 9.0 输出样例: 先输出：指定品牌的所有苹果（品牌、重量、甜度用空格隔开）；空行； 然后输出：所有高品质苹果（品牌、重量、甜度用空格隔开） ；空行； HFS: HFS 50.2 10.5 HFS 55.8 10.9 High quality: XJ 50.8 9.2 XJ 60.5 10.2 HFS 50.2 10.5 HFS 55.8 10.9

以下是C++代码实现：

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

class Apple {
public:
    string brand;
    double weight;
    double sweetness;

    Apple(string brand, double weight, double sweetness) {
        this->brand = brand;
        this->weight = weight;
        this->sweetness = sweetness;
    }

    bool operator()(const Apple &a) {
        return a.brand == brand && a.weight > 50 && a.sweetness > 9;
    }
};

int main() {
    int n;
    cin >> n;
    vector<Apple> apples;
    for (int i = 0; i < n; i++) {
        string brand;
        double weight, sweetness;
        cin >> brand >> weight >> sweetness;
        apples.emplace_back(brand, weight, sweetness);
    }

    string target_brand;
    cin >> target_brand;

    double target_weight, target_sweetness;
    cin >> target_weight >> target_sweetness;

    cout << "Specified brand:" << endl;
    for_each(apples.begin(), apples.end(), [&](const Apple &a) {
        if (a.brand == target_brand) {
            cout << a.brand << " " << a.weight << " " << a.sweetness << endl;
        }
    });
    cout << endl;

    cout << "High quality:" << endl;
    vector<Apple> high_quality;
    copy_if(apples.begin(), apples.end(), back_inserter(high_quality), Apple(target_brand, target_weight, target_sweetness));
    for_each(high_quality.begin(), high_quality.end(), [](const Apple &a) {
        cout << a.brand << " " << a.weight << " " << a.sweetness << endl;
    });
    cout << endl;

    return 0;
}