1、编写程序实现如下教学管理场景中的应用： （1） 设计学生、老师和课程类见下图， （2）老师能够开课，学生能选课 （3） 在主方法中测试见图2： l 老师创建一门课程，并添加58位学生来选择该课程。 l 统计出58位学生中男女数量及比重。

代码如下：

// 学生类
class Student {
    private String name;
    private String gender;

    public Student(String name, String gender) {
        this.name = name;
        this.gender = gender;
    }

    public String getName() {
        return name;
    }

    public String getGender() {
        return gender;
    }
}

// 老师类
class Teacher {
    private String name;
    private List<Course> courses = new ArrayList<>();

    public Teacher(String name) {
        this.name = name;
    }

    public void addCourse(Course course) {
        courses.add(course);
    }

    public List<Course> getCourses() {
        return courses;
    }
}

// 课程类
class Course {
    private String name;
    private List<Student> students = new ArrayList<>();

    public Course(String name) {
        this.name = name;
    }

    public void addStudent(Student student) {
        students.add(student);
    }

    public List<Student> getStudents() {
        return students;
    }

    public int getMaleCount() {
        int count = 0;
        for (Student student : students) {
            if (student.getGender().equals("male")) {
                count++;
            }
        }
        return count;
    }

    public int getFemaleCount() {
        int count = 0;
        for (Student student : students) {
            if (student.getGender().equals("female")) {
                count++;
            }
        }
        return count;
    }

    public double getMaleProportion() {
        int maleCount = getMaleCount();
        int totalCount = students.size();
        return (double) maleCount / totalCount;
    }

    public double getFemaleProportion() {
        int femaleCount = getFemaleCount();
        int totalCount = students.size();
        return (double) femaleCount / totalCount;
    }
}

public class Main {
    public static void main(String[] args) {
        Teacher teacher = new Teacher("张三");
        Course course = new Course("Java基础");
        teacher.addCourse(course);

        for (int i = 1; i <= 58; i++) {
            String gender = i % 2 == 0 ? "male" : "female";
            Student student = new Student("学生" + i, gender);
            course.addStudent(student);
        }

        int maleCount = course.getMaleCount();
        int femaleCount = course.getFemaleCount();
        double maleProportion = course.getMaleProportion();
        double femaleProportion = course.getFemaleProportion();

        System.out.println("男生人数：" + maleCount);
        System.out.println("女生人数：" + femaleCount);
        System.out.println("男生比例：" + maleProportion);
        System.out.println("女生比例：" + femaleProportion);
    }
}

输出结果为：

男生人数：29
女生人数：29
男生比例：0.5
女生比例：0.5