[HackerRank] Solve Java

2. Java If-Else

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {



    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {
        int N = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        if (N%2 != 0)
        {System.out.println("Weird");}
        else if (N>=2 && N<=5)
        {System.out.println("Not Weird");}
        else if (N>5 && N<=20)
        {System.out.println("Weird");}
        else if (N>20)
        {System.out.println("Not Weird");}

        scanner.close();
    }
}

 

3. Java Stdin and Stdout I

import java.util.*;

public class Solution {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        int c = scan.nextInt();

        System.out.println(a);
        System.out.println(b);
        System.out.println(c);
    }
}

 

 

4. Java Stdin and Stdout II

import java.util.Scanner;

public class Solution {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        
        int i = scan.nextInt();
        double d = scan.nextDouble();
        scan.nextLine();//버퍼주기
        String s = scan.nextLine();

        System.out.println("String: " + s);
        System.out.println("Double: " + d);
        System.out.println("Int: " + i);
    }
}

 

5. Java Output Formatting

import java.util.Scanner;

public class Solution {

    public static void main(String[] args) {
            Scanner sc=new Scanner(System.in);
            System.out.println("================================");
            for(int i=0;i<3;i++){
                String s1=sc.next();
                int x=sc.nextInt();
                System.out.printf("%-15s%03d \n", s1, x);
            }
            System.out.println("================================");

    }
}

 

6. Java Loops I

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {



    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {
        int N = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
        int i = 1;

        while(i<11){
        int result = N * i;
        System.out.printf("%d x %d = %d\n",N,i,result );
        i++;
        }
        scanner.close();
    }
}

 

7. Java Loops II

import java.util.*;
import java.io.*;

class Solution{
    public static void main(String []argh){
        Scanner in = new Scanner(System.in);
        int t=in.nextInt();
        for(int i=0;i<t;i++){
            int a = in.nextInt();
            int b = in.nextInt();
            int n = in.nextInt();

            for(int j=0; j<n; j++){
                a= a+b;
                
                if(j>0){
                    System.out.print(" ");
                }
                System.out.print(a);
                    b= 2*b;

            }
               System.out.printf("\n");
        }

        in.close();
    }
}

 

8. Java Datatypes

import java.util.*;
import java.io.*;



class Solution{
    public static void main(String []argh)
    {



        Scanner sc = new Scanner(System.in);
        int t=sc.nextInt();

        for(int i=0;i<t;i++)
        {

            try
            {
                long x=sc.nextLong();
                System.out.println(x+" can be fitted in:");
                
                if(x >= Byte.MIN_VALUE && x <= Byte.MAX_VALUE)
                System.out.println("* byte");
                if(x >= Short.MIN_VALUE && x <= Short.MAX_VALUE)
                System.out.println("* short");
                if(x >= Integer.MIN_VALUE && x <= Integer.MAX_VALUE)
                System.out.println("* int");
                if(x >= Long.MIN_VALUE && x <= Long.MAX_VALUE)
                System.out.println("* long");
                
            }
            catch(Exception e)
            {
                System.out.println(sc.next()+" can't be fitted anywhere.");
            }

        }
    }
}

 

9. Java End-of-file

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {


        Scanner scan = new Scanner(System.in);

        int i = 1;

        while(scan.hasNext()){
            System.out.println(i+ " "+ scan.nextLine());
            i++;
        }
        //scan.hasNext()는 다음신호가 있을때까지 무한반복임. 아니면 값을 넣어주면 True를 반환하기도함.

        scan.close();
        //scan.close()는 스캔을 그만두는것.




    }
}

 

10. Java Static Initializer Block

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

private static int B;
private static int H;
private static boolean flag;
 
 static{
    Scanner scan = new Scanner(System.in);
    B = scan.nextInt();
    H = scan.nextInt();
    scan.close();

    if(B<=0 || H<=0)
    {System.out.println("java.lang.Exception: Breadth and height must be positive");
    flag = false;}
    else {flag = true;
}
}

public static void main(String[] args){
		if(flag){
			int area=B*H;
			System.out.print(area);
		}
		
	}//end of main

}//end of class

 

--

Java Date and Time

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

class Result {

    public static String findDay(int month, int day, int year) {

        Calendar cal = Calendar.getInstance(); 
        //캘린더클래스사용방법 로컬시스템시간정보를 표현하도록함.


        cal.set(Calendar.MONTH, month-1);
        //:1월= 0 이라 -1해줌.

        cal.set(Calendar.DATE, day);


        cal.set(Calendar.YEAR, year);
        //현제 로컬날짜를 설정해서 바꿈.


        String[] day_of_week = {"SUNDAY", "MONDAY", "TUESDAY", "WEDNESDAY", "THURSDAY", "FRIDAY","SATURDAY"};
        //문제에서 string으로 표현하라했으니 설정


        return day_of_week[cal.get(Calendar.DAY_OF_WEEK)-1];
        //일요일은 = 1, 토요일=7

    }

}

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        String[] firstMultipleInput = bufferedReader.readLine().replaceAll("\\s+$", "").split(" ");

        int month = Integer.parseInt(firstMultipleInput[0]);

        int day = Integer.parseInt(firstMultipleInput[1]);

        int year = Integer.parseInt(firstMultipleInput[2]);

        String res = Result.findDay(month, day, year);

        bufferedWriter.write(res);
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}