Chapter 2. 연습문제

이론문제

실습문제 1

import java.util.Scanner;

public class sd {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		System.out.println("두 정수를 입력하세요>>");
		int i=scanner.nextInt();
		int j=scanner.nextInt();
		int z=i+j;
		System.out.println(i+"+"+j+"은 "+z);
        scanner.close();
	}

}

실습문제 2

import java.util.Scanner;

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

}

실습문제 3

import java.util.Scanner;

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

실습문제 4

import java.util.Scanner;

public class sd {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		System.out.println("점 (x,y)의 좌표를 입력하세요>>");
		int x=scanner.nextInt();
		int y=scanner.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");
        scanner.close();
	}

}

실습문제 5

import java.util.Scanner;

public class sd {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		System.out.println("논리 연산을 입력하세요>>");
		boolean x=scanner.nextBoolean();
		String op=scanner.next();
		boolean y=scanner.nextBoolean();
		switch(op) {
		case "AND" : 
			System.out.println(x&&y);
			break;
		case "OR" :
			System.out.println(x||y);
			break;
		}
		scanner.close();
	}
}

실습문제 6

import java.util.Scanner;

public class sd {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		System.out.println("돈의 액수를 입력하세요>>");
		int money=scanner.nextInt();
		int fiveman=money/50000;
		int man=money%50000/10000;
		int cheon=money%50000%10000/1000;
		int fivebaek=money%50000%10000%1000/500;
		int baek=money%50000%10000%1000%500/100;
		int sip=money%50000%10000%1000%500%100/10;
		int ill=money%50000%10000%1000%500%100%10;
		System.out.println("오만원"+fiveman+"개, 만원"+man+"개, 천원"+cheon+"개, 500원"+fivebaek+"개, 100원"+baek+"개, 10원"+sip+"개, 1원"+ill+"개");
		scanner.close();
	}
}

실습문제 7

import java.util.Scanner;

public class sd {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		System.out.println("학점을 입력하세요>>");
		String score=scanner.next();
		switch (score) {
		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;
		}
		scanner.close();
	}
}

실습문제 8-1

import java.util.Scanner;

public class sd {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		System.out.println("커피 주문하세요>>");
		String coffee=scanner.next();
		int number=scanner.nextInt();
		if(coffee.equals("에스프레소"))
			System.out.println(2000*number+"원입니다.");
		else if (coffee.equals("아메리카노"))
			System.out.println(2500*number+"원입니다.");
		else if (coffee.equals("카푸치노"))
			System.out.println(3000*number+"원입니다.");
		else if (coffee.equals("카페라떼"))
			System.out.println(3500*number+"원입니다.");
		scanner.close();
	}
}

실습문제 8-2

import java.util.Scanner;

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

실습문제 9

import java.util.Scanner;

public class sd {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		System.out.println("1~99사이의 정수를 입력하세요>>");
		int number=scanner.nextInt();
		int first=number/10;
		int second=number%10;
		if ((first%3==0)&&(second%3==0))
			System.out.println("박수짝짝");
		else if ((first%3==0)||(second%3==0))
			System.out.println("박수짝");
		else 
			System.out.println("박수없음");
		scanner.close();
	}
}

실습문제 10

import java.util.Scanner;

public class sd {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		System.out.println("커피 주문하세요>>");
		String coffee=scanner.next();
		int number=scanner.nextInt();
		if(coffee.equals("에스프레소"))
			if((number>=10))
				System.out.println(2000*number*0.95+"원입니다.");
			else
				System.out.println(2000*number+"원입니다.");
		else if (coffee.equals("아메리카노"))
			System.out.println(2500*number+"원입니다.");
		else if (coffee.equals("카푸치노"))
			System.out.println(3000*number+"원입니다.");
		else if (coffee.equals("카페라떼"))
			System.out.println(3500*number+"원입니다.");
		scanner.close();
	}
}