建立一个数组将实训12第2题定义的 学生数据存入数组。 数据为： { {"2020B200301","刘滨","男",18,{2020,9,20},70,85}, {"2020B200302","阚美娟","女",17,{2020,9,20},87,95}, {"2020B200303","胡大勇","男",17,{2020,9,20},69,80}, {"2020B200305","黎丽","女",18,{2020,9,20},68,88}, {"2020B200309","金鑫","男",19,{2019,9,1},90,85} } 将这些数据写人磁盘保存将上题的成绩加密保存，当读出数据，密码不对成绩显示**号。（密钥由字母构成）起来。

以下是一个示例代码，将实训12第2题定义的学生数据存入数组，并且对成绩进行了加密保存，当读取数据时，如果密码不正确，则成绩将显示为星号：

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
using namespace std;

// 定义学生结构体
struct Student {
    string id;       // 学号
    string name;     // 姓名
    string gender;   // 性别
    int age;         // 年龄
    int birthday[3]; // 生日，用数组表示，依次为年、月、日
    int score1;      // 成绩1
    int score2;      // 成绩2
};

// 加密函数
string encrypt(string str, string key) {
    for (int i = 0; i < str.length(); i++) {
        str[i] = str[i] ^ key[i % key.length()];
    }
    return str;
}

// 解密函数
string decrypt(string str, string key) {
    return encrypt(str, key);
}

int main() {
    // 定义学生数组
    const int N = 5;
    Student students[N] = {
        {"2020B200301", "刘滨", "男", 18, {2020, 9, 20}, 70, 85},
        {"2020B200302", "阚美娟", "女", 17, {2020, 9, 20}, 87, 95},
        {"2020B200303", "胡大勇", "男", 17, {2020, 9, 20}, 69, 80},
        {"2020B200305", "黎丽", "女", 18, {2020, 9, 20}, 68, 88},
        {"2020B200309", "金鑫", "男", 19, {2019, 9, 1}, 90, 85},
    };

    // 加密并保存到文件
    string key = "abcd1234";
    ofstream out("students.dat");
    for (int i = 0; i < N; i++) {
        out << encrypt(students[i].id, key) << ","
            << encrypt(students[i].name, key) << ","
            << encrypt(students[i].gender, key) << ","
            << students[i].age << ","
            << students[i].birthday[0] << ","
            << students[i].birthday[1] << ","
            << students[i].birthday[2] << ","
            << encrypt(to_string(students[i].score1), key) << ","
            << encrypt(to_string(students[i].score2), key) << endl;
    }
    out.close();

    // 从文件中读取并解密
    ifstream in("students.dat");
    string line;
    while (getline(in, line)) {
        istringstream iss(line);
        string id, name, gender, score1, score2;
        int age, year, month, day;
        getline(iss, id, ',');
        getline(iss, name, ',');
        getline(iss, gender, ',');
        iss >> age >> year >> month >> day >> score1 >> score2;
        // 解密
        id = decrypt(id, key);
        name = decrypt(name, key);
        gender = decrypt(gender, key);
        score1 = decrypt(score1, key);
        score2 = decrypt(score2, key);
        // 判断密码是否正确
        string password;
        cout << "请输入密码：";
        cin >> password;
        if (password == key) {
            cout << "学号：" << id << endl;
            cout << "姓名：" << name << endl;
            cout << "性别：" << gender << endl;
            cout << "年龄：" << age << endl;
            cout << "生日：" << year << "年" << month << "月" << day << "日" << endl;
            cout << "成绩1：" << score1 << endl;
            cout << "成绩2：" << score2 << endl;
        } else {
            cout << "学号：" << id << endl;
            cout << "姓名：" << name << endl;
            cout << "性别：" << gender << endl;
            cout << "年龄：" << age << endl;
            cout << "生日：" << year << "年" << month << "月" << day << "日" << endl;
            cout << "成绩1：" << "****" << endl;
            cout << "成绩2：" << "****" << endl;
        }
    }
    in.close();

    return 0;
}

在这个例子中，我们使用了 `encrypt()` 和 `decrypt()` 函数来进行加密和解密。在保存数据到文件时，我们将学生的各项数据转换为字符串，并使用逗号分隔，然后按行写入文件。在读取数据时，我们使用 `getline()` 函数读取每行数据，并使用逗号分隔解析出每个字段。然后，我们使用 `decrypt()` 函数对学生的各项数据进行解密。最后，我们要求用户输入密码，并判断密码是否正确。如果密码正确，则将成绩正常显示；否则，将成绩显示为星号。