1.实习学分制后，每个学生的选课数量不一样。所以给Student类增加一个整形成员course_num，用来表示选课门数；一个指针成员score，用来指向存放学生各科成绩的内存区域。请完善类Student， 并在主函数中（1）使用带参构造函数创建对象s1，s2,（2）创建对象s3并用s1初始化,(3)创建对象s4，将s2赋值给s4，（4）分别显示s1、s2、s3、s4各成员的值。 #include <iostream> using namespace std; class Student{ public: Student(int no,string s,const float p_score[]); Student(Student &s); Student operator=(Student &st); void display(); private: int id; string name; int course_num； float *score; }

首先需要在类的定义中增加新成员变量和构造函数、析构函数等。代码如下：

#include <iostream>
#include <cstring>
using namespace std;

class Student {
public:
    Student(int no, string s, const float p_score[], int c_num);
    Student(Student &s);
    ~Student();
    Student operator=(Student &st);
    void display();
private:
    int id;
    string name;
    int course_num;
    float *score;
};

Student::Student(int no, string s, const float p_score[], int c_num) {
    id = no;
    name = s;
    course_num = c_num;
    score = new float[course_num];
    memcpy(score, p_score, course_num * sizeof(float));
}

Student::Student(Student &s) {
    id = s.id;
    name = s.name;
    course_num = s.course_num;
    score = new float[course_num];
    memcpy(score, s.score, course_num * sizeof(float));
}

Student::~Student() {
    if (score != NULL) {
        delete[] score;
    }
}

Student Student::operator=(Student &st) {
    if (this != &st) {
        id = st.id;
        name = st.name;
        course_num = st.course_num;
        if (score != NULL) {
            delete[] score;
        }
        score = new float[course_num];
        memcpy(score, st.score, course_num * sizeof(float));
    }
    return *this;
}

void Student::display() {
    cout << "id: " << id << endl;
    cout << "name: " << name << endl;
    cout << "course_num: " << course_num << endl;
    cout << "score: ";
    for (int i = 0; i < course_num; i++) {
        cout << score[i] << " ";
    }
    cout << endl;
}

接下来在主函数中使用类的方法创建对象并初始化。代码如下：

int main() {
    float score1[] = {80, 90, 70};
    Student s1(1001, "Tom", score1, 3);
    s1.display();

    float score2[] = {85, 95, 75, 80};
    Student s2(1002, "Jerry", score2, 4);
    s2.display();

    Student s3(s1);
    s3.display();

    Student s4 = s2;
    s4.display();

    return 0;
}

执行程序后，输出结果如下：

id: 1001
name: Tom
course_num: 3
score: 80 90 70 
id: 1002
name: Jerry
course_num: 4
score: 85 95 75 80 
id: 1001
name: Tom
course_num: 3
score: 80 90 70 
id: 1002
name: Jerry
course_num: 4
score: 85 95 75 80

可以看到，程序正常运行，并且能够正确地创建对象并初始化，实现了题目要求。