題目描述：

輸入任意（使用者，成績）序列，可以獲得成績從高到低或從低到高的排列,相同成績
      都按先錄入排列在前的規則處理。

   例示：
   jack      70
   peter     96
   Tom       70
   smith     67

   從高到低  成績            
   peter     96    
   jack      70    
   Tom       70    
   smith     67    

   從低到高

   smith     67  

   Tom       70    
   jack      70    
   peter     96     

Java實現：

import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int total = sc.nextInt();
            int type = sc.nextInt();
            Student[] scores = new Student[total];
            for (int i = 0; i < total; i++) {
                String name = sc.next();
                int score = Integer.parseInt(sc.next());
                scores[i] = new Student(name, score);
            }
            if (type == 0) {
                //從大到小
                Arrays.sort(scores, new Comparator<Student>() {
                    @Override
                    public int compare(Student o1, Student o2) {
                        return o2.score - o1.score;
                    }
                });
            } else {
                Arrays.sort(scores, new Comparator<Student>() {
                    @Override
                    public int compare(Student o1, Student o2) {
                        return o1.score - o2.score;
                    }
                });
            }
            for (Student s : scores) {
                System.out.println(s.name + " " + s.score);
            }
        }
    }
}

class Student {
    String name = "";
    int score = 0;
    public Student(String name, int score) {
        this.name = name;
        this.score = score;
    }
}

知識點：

• Arrays.sort可以傳入自定義物件的陣列和比較器