노재경_Homework6

//노재경

import java.util.Scanner;
import java.util.Random;

public class Main{
    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        
        System.out.println("[주민등록번호 계산]");

        System.out.print("출생년월일을 입력해주세요 (yyyy.mm.dd): ");
        String birthDate = scanner.nextLine();
 
        System.out.print("성별을 입력해주세요 (m/f): ");
        String gender = scanner.nextLine();
        
        String[] dateParts = birthDate.split("\\."); //정규표현식써서 .기준 분리
        int year = Integer.parseInt(dateParts[0]);
        int month = Integer.parseInt(dateParts[1]);
        int day = Integer.parseInt(dateParts[2]);

        //앞쪽 6자리용
        String yearString = Integer.toString(year);
        String firstTwo = yearString.substring(yearString.length() - 2); //주민등록 번호 앞 두자리

        String monthString = String.format("%02d", month);
        
        String dayString =  String.format("%02d", day);


        //뒷쪽 7자리용
        String genderInt;
        if (gender.equals("m")) { //3항연산자를 통한 if문 간소화
            genderInt = (year < 2000) ? "1" : "3";
        } else {
            genderInt = (year < 2000) ? "2" : "4";
        }

        Random random = new Random();
        int randomNum = random.nextInt(999999) + 1;
        String randomNumString = String.format("%06d", randomNum);


        String socialNum = firstTwo + monthString + dayString + "-" + genderInt + randomNumString;
        scanner.close();
        System.out.println(socialNum);
    }
}