[Hackerrank] Data Structures - Sort 풀이

예문


https://www.hackerrank.com/challenges/java-sort/problem

Sample Input

5
33 Rumpa 3.68
85 Ashis 3.85
56 Samiha 3.75
19 Samara 3.75
22 Fahim 3.76

Sample Ouput

Ashis
Fahim
Samara
Samiha
Rumpa

해석

  • 1 번째 : CGPA 로 내림차순 정렬
  • 2 번째 : NAME 으로 알파벳순 정렬
  • 3 번째 : ID 순으로 정렬

풀이

  • Collections.sort 사용
  • Comparator 사용

제약사항

코드

class Student {
    private int id;
    private String fname;
    private double cgpa;

    public Student(int id, String fname, double cgpa) {
        super();
        this.id = id;
        this.fname = fname;
        this.cgpa = cgpa;
    }

    public int getId() {
        return id;
    }

    public String getFname() {
        return fname;
    }

    public double getCgpa() {
        return cgpa;
    }
}

//Complete the code
public class Sort {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int testCases = Integer.parseInt(in.nextLine());

        List<Student> studentList = new ArrayList<Student>();
        while (testCases > 0) {
            int id = in.nextInt();
            String fname = in.next();
            double cgpa = in.nextDouble();

            Student st = new Student(id, fname, cgpa);
            studentList.add(st);

            testCases--;
        }

        Collections.sort(studentList, Comparator.comparing(Student::getCgpa).reversed()
                .thenComparing(Student::getFname)
                .thenComparing(Student::getId));

        for (Student st : studentList) {
            System.out.println(st.getFname());
        }
    }
}