成绩排序

使用 Comparator

import java.util.*;

class Student{
    private int grade;
    private String name;
    public static final Comparator<Student> INCREASE = new increase();
    public static final Comparator<Student> DECREASE = new decrease();
    public Student(String name, int grade) {this.name = name;
        this.grade = grade;
    }
    public String toString() {
        return name + " " + grade;
    }
    private static class increase implements Comparator<Student> {
        public int compare(Student v, Student w) {
            return w.grade - v.grade;
        }
    } 
    private static class decrease implements Comparator<Student> {
        public int compare(Student v, Student w) {
            return v.grade - w.grade;
        }
    }
}
public class Main { 

    public Main() {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) {
            int n = Integer.valueOf(in.next());
            int flag = Integer.valueOf(in.next());
            Student[] students = new Student[n];
            for (int i = 0; i < n; i++) {
                students[i] = new Student(in.next(), Integer.valueOf(in.next()));
            }
            if (flag == 1) {
                Arrays.sort(students, Student.DECREASE);
            }
            else {
                Arrays.sort(students, Student.INCREASE);
            }
            for (Student student : students) {
                System.out.println(student);
            }
        }
    }

    public static void main(String[] args) 
    {
        Main solution = new Main();
    } }