Java sort priority_queue map 比較函數

1. Sort

1.1 自定義類型 

package test;

import java.util.Comparator;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

class MyComparator implements Comparator {

	public int compare(Object o1, Object o2) {
		StudentNoCmp p1 = (StudentNoCmp) o1;
		StudentNoCmp p2 = (StudentNoCmp) o2;
		// if (p1.score < p2.score)
		// return 1;
		// else if (p1.score > p2.score)
		// return -1;
		// else
		// return 0;
		//
		// jim : 92
		// tom : 89
		// jack : 77
		return p1.score - p2.score;
	}
}

class StudentNoCmp {
	String name;
	int score;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getScore() {
		return score;
	}

	public void setScore(int score) {
		this.score = score;
	}
}

class Student implements Comparable<Student> {

	String name;
	int score;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getScore() {
		return score;
	}

	public void setScore(int score) {
		this.score = score;
	}

	@Override
	public int compareTo(Student o) {
		return score - o.score;
	}
}

public class sort_cmp_node {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		List s = new ArrayList();
		StudentNoCmp b = new StudentNoCmp();
		b.name = "tina";
		b.score = 89;
		s.add(b);

		b = new StudentNoCmp();
		b.name = "jessie";
		b.score = 92;
		s.add(b);

		b = new StudentNoCmp();
		b.name = "Jim";
		b.score = 77;
		s.add(b);

		for (int i = 0; i < s.size(); i++) {
			b = (StudentNoCmp) s.get(i);
			System.out.println(b.name + " : " + b.score);
		}

		System.out.println("------------------------");

		Collections.sort(s, new MyComparator());

		for (int i = 0; i < s.size(); i++) {
			b = (StudentNoCmp) s.get(i);
			System.out.println(b.name + " : " + b.score);
		}

		ArrayList<Student> ss = new ArrayList<>();
		Student bb = new Student();
		bb.name = "tina";
		bb.score = 89;
		ss.add(bb);

		bb = new Student();
		bb.name = "jessie";
		bb.score = 92;
		ss.add(bb);

		bb = new Student();
		bb.name = "Jim";
		bb.score = 77;
		ss.add(bb);
		System.out.println("------------------------");
		Collections.sort(ss);
		for (int i = 0; i < ss.size(); i++) {
			bb = ss.get(i);
			System.out.println(bb.name + " : " + bb.score);
		}
		// output
		// tina : 89
		// jessie : 92
		// Jim : 77
		// ------------------------
		// Jim : 77
		// tina : 89
		// jessie : 92
		// ------------------------
		// Jim : 77
		// tina : 89
		// jessie : 92

	}

}