package chapter6;

import java.util.HashSet;
import java.util.Iterator;

class Student implements Comparable<Student> {
    String id;
    String name;
    int height;

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

    public void setHeight(int height) {
        this.height = height;
    }

    public String toString() {
        return id + ":" + name;
    }

    public int hashCode() {
        return id.hashCode();
    }

    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }

        if (!(obj instanceof Student)) {
            return false;
        }

        Student other = (Student) obj;
        return this.id.equals(other.id);
    }

    public int compareTo(Student other) {
        if (this.height > other.height) {
            return 1; // 返回正数：表示"我"比"你"大
        } else if (this.height < other.height) {
            return -1;  // 返回负数：表示"我"比"你"小
        } else {
            return 0; // 返回0：表示"我"和"你"一样大
        }
    }
}

public class Example08 {
    public static void main(String[] args) {
        HashSet<Student> students = new HashSet<>();

        Student s1 = new Student("1", "张三");
        Student s2 = new Student("2", "李四");
        Student s3 = new Student("2", "李四");
        Student s4 = new Student("3", "王五");

        students.add(s3);
        students.add(s4);
        students.add(s1);
        students.add(s2);

        Iterator<Student> iterator = students.iterator();
        while (iterator.hasNext()) {
            Student student = iterator.next();
            System.out.println(student);
        }

    }
}