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package class06;
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import java.util.Comparator;
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import java.util.PriorityQueue;
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public class ShowComparator2 {
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public static class MyComparator implements Comparator<Integer> {
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// 负，第一个参数在前
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// 正，第二个参数在前
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// 0, 谁放前都行
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@Override
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public int compare(Integer o1, Integer o2) {
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if (o1 < o2) {
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return 1;
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} else if (o1 > o2) {
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return -1;
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} else {
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return 0;
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}
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}
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}
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public static class Student {
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public String name;
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public int id;
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public int age;
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public Student(String name, int id, int age) {
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this.name = name;
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this.id = id;
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this.age = age;
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}
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}
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// 谁id大，谁放前！
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public static class IdComparator implements Comparator<Student> {
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// 如果返回负数，认为第一个参数应该排在前面
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// 如果返回正数，认为第二个参数应该排在前面
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// 如果返回0，认为谁放前面无所谓
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@Override
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public int compare(Student o1, Student o2) {
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if (o1.id < o2.id) {
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return 1;
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} else if (o2.id < o1.id) {
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return -1;
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} else {
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return 0;
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}
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}
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}
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public static void main(String[] args) {
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String str1 = "abc";
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String str2 = "b";
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System.out.println(str1.compareTo(str2));
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PriorityQueue<Student> heap = new PriorityQueue<>(new IdComparator());
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Student s1 = new Student("张三", 5, 27);
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Student s2 = new Student("李四", 1, 17);
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Student s3 = new Student("王五", 4, 29);
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Student s4 = new Student("赵六", 3, 9);
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Student s5 = new Student("左七", 2, 34);
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heap.add(s1);
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heap.add(s2);
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heap.add(s3);
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heap.add(s4);
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heap.add(s5);
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System.out.println("=========");
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while (!heap.isEmpty()) {
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Student s = heap.poll();
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System.out.println(s.name + ", " + s.id + ", " + s.age);
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}
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}
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}
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