명품 자바 에센셜 2장 실습 문제

1번

import java.util.Scanner;

public class One{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("두 정수를 입력하세요>>");
		int x= sc.nextInt();
		int y= sc.nextInt();
		System.out.println(x+ "+" +y +"은 "+(x+y));
		sc.close();
	}
	
}

2번

import java.util.Scanner;

public class Two{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("몇 층인지 입력하세요>>");
		int x= sc.nextInt();
		System.out.println((x*5)+"m 입니다.");
		sc.close();
	}
	
}

3번

import java.util.Scanner;

public class Three{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("x 값을 입력하세요>>");
		int x= sc.nextInt();
		System.out.println("x="+x+", y="+(x*x-3*x+7));
		sc.close();
	}
	
}

4번

import java.util.Scanner;

public class Four{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("점 (x,y)의 좌표를 입력하세요>>");
		int x= sc.nextInt();
		int y= sc.nextInt();
		if ((x>=50 && x<=100)&&(y>=50 && y<=100)) {
			System.out.println("점(" + x + "," + y + ")" + "은 (50, 50)과 (100, 100)의 사각형 내에 있습니다.");
			}
		else {
			System.out.println("점(" + x + "," + y + ")" + "은 (50, 50)과 (100, 100)의 사각형 내에 있지 않습니다.");
		}
		sc.close();
	}
	
}

5번

import java.util.Scanner;

public class Five{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("논리 연산을 입력하세요>>");
		boolean a=sc.nextBoolean();
		String op=sc.next();
		boolean b=sc.nextBoolean();
		
		switch(op) {
		case "AND" : {System.out.println(a && b);break;}
		case "OR" : {System.out.println(a || b);break;}
		}

		sc.close();
	}
	
}

6번

import java.util.Scanner;

public class Six{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("돈의 액수를 입력하세요>>");
		int money=sc.nextInt();
		int rest=money;
		
		money/=50000;
		System.out.print("오만원"+money+"개, ");
		money=rest%50000;
		
		money/=10000;
		System.out.print("만원"+money+"개, ");
		money=rest%10000;
		
		money/=1000;
		System.out.print("천원"+money+"개, ");
		money=rest%1000;
		
		money/=500;
		System.out.print("500원"+money+"개, ");
		money=rest%500;
		
		money/=100;
		System.out.print("100원"+money+"개, ");
		money=rest%100;

		money/=10;
		System.out.print("10원"+money+"개, ");
		money=rest%10;

		System.out.print("1원"+money+"개");


		sc.close();
	}
	
}

7번

import java.util.Scanner;

public class Seven{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("학점을 입력하세요>>");
		String grade=sc.next();
		
		switch(grade) {
		case "A":case"B":{
			System.out.println("Excellent");
			break;
		}
		
		case "C":case"D":{
			System.out.println("Good");
			break;
		}
		case "F":{
			System.out.println("Bye");
			break;
		}
		default:{
			System.out.println("잘못된 성적 입력입니다.");
			break;
		}
	}



		sc.close();
	}
	
}

8번

import java.util.Scanner;

public class One{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("커피 주문하세요>>");
		String coffee=sc.next();
		int num=sc.nextInt();
		
		switch(coffee) {
		case "에스프레소":{
			System.out.println(2000*num+"원입니다.");
			break;}
		case "아메리카노":{
			System.out.println(2500*num+"원입니다.");
			break;}
		case "카푸치노":{
			System.out.println(3000*num+"원입니다.");
			break;}
		case "카페라떼":{
			System.out.println(3500*num+"원입니다.");
			break;}

	}



		sc.close();
	}
	
}

import java.util.Scanner;

public class One{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		System.out.print("커피 주문하세요>>");
		String coffee=sc.next();
		int num=sc.nextInt();
		

		if (coffee.equals("에스프레소")){
			System.out.println(2000*num+"원입니다.");}
		else if(coffee.equals("아메리카노")){
			System.out.println(2500*num+"원입니다.");}
		else if (coffee.equals("카푸치노")){
			System.out.println(3000*num+"원입니다.");}
		else if (coffee.equals("카페라떼")){
			System.out.println(3500*num+"원입니다.");}

		sc.close();
	}
	
}

9번

import java.util.Scanner;
public class nine {
	public static void main (String[] args) {
		System.out.print("1~99 사이의 정수를 입력하세요>>");
		Scanner scanner=new Scanner(System.in);
		int num=scanner.nextInt();
		int a= num/10;
		int b= num%10;
		System.out.print("박수");
		if ((a==3 || a==6 || a==9) || (b==3 || b==6 || b==9)) {
			System.out.print("짝");
			if ((a==3 || a==6 || a==9) && (b==3 || b==6 || b==9)) {
				System.out.print("짝");
			}
		}
		else {
			System.out.print("없음");
		}

	}

}

10번

import java.util.Scanner;
public class ten{
	public static void main(String[] args) {
		System.out.print("커피 주문하세요>>");
		Scanner scanner=new Scanner(System.in);
		
		String coffee=scanner.next();
		int num=scanner.nextInt();
		
		if (coffee.equals("에스프레소")){
			if (num>=10){
				System.out.print((int)(num*2000*0.95)); 
                //형 변환 주의!!-> 정수 형태로 할인된 값 출력되도록!!
			}
			else {
				System.out.print(num*2000);
			}
		}
		else if (coffee.equals("아메리카노")) {
			System.out.print(num*2500);
		}
		else if (coffee.equals("카푸치노")) {
			System.out.print(num*3000);
		}
		else if (coffee.equals("카페라떼")) {
			System.out.print(num*3500);
		}
		
		System.out.print("원입니다.");
	}
}

bonus1

import java.util.Scanner;
public class bonus{
	public static void main(String[] args) {
		System.out.println("식을 입력하세요>>");
		Scanner scanner=new Scanner(System.in);
		double op1=scanner.nextDouble();
		String op=scanner.next();
		double op2=scanner.nextDouble();
		double result=0;

		switch(op) {
		case "+" : { result=op1+op2;break;}
		case "-" : { result=op1-op2;break;}
		case "*" : { result=op1*op2;break;}
		case "/" : { 
			if (op2==0) {System.out.println("0으로 나눌 수 없습니다.");return;}
			result=op1/op2;
			break;}
		default:System.out.println("연산 기호가 잘못되었습니다.");
		}
		System.out.println("연산 결과 "+result);
	}
}