[BACKJOON/JAVA] 단계별로 풀어보기 3단계

백준 단계별로 풀어보기 3단계 [반복문]

• 단계 : 3-1
• 문제 : #2739
• 문제 제목 : 구구단

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

        int n = in.nextInt();
        in.close();

        for ( int i=1; i< 10; i++){
            System.out.println( n +" * " + i + " = " + n*i);
        }
    }
}

• 단계 : 3-2
• 문제 : #10950
• 문제 제목 : A+B - 3

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

        // 테스트 케이스 개수
        int t = in.nextInt();

        for (int i =0; i < t ; i++){
            int a = in.nextInt();
            int b = in.nextInt();

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

        in.close();
    }
}

• 단계 : 3-3
• 문제 : #8393
• 문제 제목 : 합

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

        int n = in.nextInt();
        in.close();

        int sum = 0;
        for ( int i =1 ; i <= n; i ++){
            sum += i;
        }
        System.out.println( sum );
    }
}

• 단계 : 3-4
• 문제 : #25304
• 문제 제목 : 영수증

public class Main {
    
    public static void main(String[] args) {
        
        Scanner in = new Scanner(System.in);
        int total = in.nextInt();
        int n = in.nextInt();
        int sum = 0;

        for ( int i=0; i < n; i ++){
            int money = in.nextInt();
            int any = in.nextInt();

            sum += money * any;
        }

        in.close();
        
        if( total == sum){
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
}

• 단계 : 3-5
• 문제 : #25314
• 문제 제목 : 코딩은 체육과목 입니다

public class Main {
    
    public static void main(String[] args) {
        
        Scanner in = new Scanner(System.in);
        String str = "";
        int n = in.nextInt();

        in.close();

        int cnt = n/4;
        for (int i =0; i < cnt; i++){
            str += "long ";
        }

        System.out.println(str + "int");
    
    }
}

• 단계 : 3-6
• 문제 : #15552
• 문제 제목 : 빠른 A+B

public class Main {
 
	public static void main(String[] args) throws IOException {
 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
 
 
		int N = Integer.parseInt(br.readLine());
        
		StringTokenizer st;
 
		for (int i = 0; i < N; i++) {
			st = new StringTokenizer(br.readLine()," ");
			bw.write((Integer.parseInt(st.nextToken()) + Integer.parseInt(st.nextToken()))+ "\n");
		}
		br.close();
		bw.flush();
		bw.close();
 
	}
}

• 단계 : 3-7
• 문제 : #11021
• 문제 제목 : A+B - 7

public class Main {
    
    public static void main(String[] args) {
        
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        for ( int i = 1; i<= n; i++){
            int a = in.nextInt();
            int b = in.nextInt();

            System.out.println("Case #"+i+": "+ (a+b));
        }

        in.close();
    
    }
}

• 단계 : 3-8
• 문제 : #11022
• 문제 제목 : A+B - 8

public class Main {
    
    public static void main(String[] args) {
        
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        for ( int i = 1; i<= n; i++){
            int a = in.nextInt();
            int b = in.nextInt();

            System.out.println("Case #"+i+": "+a+" + " + b +" = "+ (a+b));
        }

        in.close();

    
    }
}

• 단계 : 3-9
• 문제 : #2438
• 문제 제목 : 별 찍기 - 1

public class Main {
    
    public static void main(String[] args) {
        
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        
        String str = "";
        for ( int i = 1; i<= n; i++){
            for ( int j = 1; j <= n-i; j++){
                System.out.print(" ");
            }
            for ( int k = 1; k <= i; k++){
                System.out.print("*");
            }
            System.out.println();
        }
           
        in.close();
    
    }
}

• 단계 : 3-10
• 문제 : #10951
• 문제 제목 : A+B - 4

public class Main {
    
    public static void main(String[] args) {
        
        Scanner in = new Scanner(System.in);
        
        while(in.hasNextInt()){
            int a = in.nextInt();
            int b = in.nextInt();
            
            System.out.println(a+b);
        }
        in.close();
    
    }
}