[백준 - JAVA] 10814번 나이순 정렬

https://www.acmicpc.net/problem/10814

10814번: 나이순 정렬

// ArrayList에다 차례대로 넣으면 먼저 온 순서대로는 맞춰지고 나이에 따라 정렬해주면 되겠다!
// 프로덕션코드


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

public class Yun_10814 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int numberOfMember = scanner.nextInt();
        scanner.nextLine();

        Member[] members = new Member[numberOfMember];
        for (int i = 0; i < numberOfMember; i++) {
            String[] input = scanner.nextLine().split(" ");
            members[i] = new Member(input[0], input[1]);
        }

        Arrays.sort(members, new Comparator<Member>() {
            @Override
            public int compare(Member o1, Member o2) {
                if (o1.age != o2.age) {
                    return o1.age - o2.age;
                }
                return -1;
            }
        });

        for (int i = 0; i < numberOfMember; i++) {
            System.out.println(members[i].age + " " + members[i].name);
        }


    }
}

class Member {
    int age;
    String name;

    Member(int age, String name) {
        this(Integer.toString(age), name);
    }

    Member(String age, String name) {
        this.age = Integer.parseInt(age);
        this.name = name;
    }
}

// 실패? Arrays.sort하면 먼저 온 순서까지 뒤틀려 버리네? 메소드 자세히 살펴보자!

원래 등록한 순서대로 넣어 놨지만 sort 이후에 정렬이 흐트러진 모습

sort 메소드

......? LegacyMergeSort...? TimSort? 이해하기에는 내공이 딸린다... 일단 순서가 유지되지 않는다는 것만 알아두자..

// 그럼 sort 메소드 안에 compare 메소드 구현할때 두 조건을 동시에 넣어야한다는 뜻인데...
// 처음 멤버 객체 만들어줄때 순서도 같이 넣어주자! 그리고 나이같을 경우에는 순서 고려!

//프로덕션코드


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

public class Yun_10814 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int numberOfMember = scanner.nextInt();
        scanner.nextLine();

        Member[] members = new Member[numberOfMember];
        for (int i = 0; i < numberOfMember; i++) {
            String[] input = scanner.nextLine().split(" ");
            members[i] = new Member(input[0], input[1], i);
        }

        Arrays.sort(members, new Comparator<Member>() {
            @Override
            public int compare(Member o1, Member o2) {
                if (o1.age != o2.age) {
                    return o1.age - o2.age;
                }
                return o1.order - o2.order;
            }
        });

        for (int i = 0; i < numberOfMember; i++) {
            System.out.println(members[i].age + " " + members[i].name);
        }


    }
}

class Member {
    int age;
    String name;
    int order;

    Member(int age, String name, int order) {
        this(Integer.toString(age), name, order);
    }

    Member(String age, String name, int order) {
        this.age = Integer.parseInt(age);
        this.name = name;
        this.order = order;
    }
}


// 성공! 리팩토링하자

// 프로덕션코드


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

public class Yun_10814 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int numberOfMember = scanner.nextInt();
        scanner.nextLine();

        Member[] members = new Member[numberOfMember];
        setmembers(scanner, numberOfMember, members);

        sorting(members);
        print(numberOfMember, members);
    }

    private static void print(int numberOfMember, Member[] members) {
        for (int i = 0; i < numberOfMember; i++) {
            System.out.println(members[i].age + " " + members[i].name);
        }
    }

    private static void sorting(Member[] members) {
        Arrays.sort(members, new Comparator<Member>() {
            @Override
            public int compare(Member o1, Member o2) {
                if (o1.age != o2.age) {
                    return o1.age - o2.age;
                }
                return o1.order - o2.order;
            }
        });
    }

    private static void setmembers(Scanner scanner, int numberOfMember, Member[] members) {
        for (int i = 0; i < numberOfMember; i++) {
            String[] input = scanner.nextLine().split(" ");
            members[i] = new Member(input[0], input[1], i);
        }
    }
}

class Member {
    int age;
    String name;
    int order;

    Member(int age, String name, int order) {
        this(Integer.toString(age), name, order);
    }

    Member(String age, String name, int order) {
        this.age = Integer.parseInt(age);
        this.name = name;
        this.order = order;
    }
}

// 성공!