[백준]5단계 문제 모음

1

10818

최소, 최대

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(System.in);
		int T = scan.nextInt();
		int a[] = new int[T];
		
		for(int i=0; i<T; i++) {
			int b = scan.nextInt();
			a[i] = b;
		}
		int max = a[0];
		int min = a[0];
		
		for(int i=1; i<T; i++) {
			if( a[i] > max)
				max = a[i];
			if(a[i] < min)
				min = a[i];
		}
		
		System.out.print(min + " ");
		System.out.print(max);
	}

}

---

 

2

2562

최댓값

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan =new Scanner(System.in);
		int T = 9;
		int a[] = new int[T];
		for(int i=0; i<T; i++) {
			a[i] = scan.nextInt();
		}
		int max = a[0];
		int number = 1;
		for(int i=0; i<T; i++) {
			if(a[i]>max) {
				max=a[i];
				number = i+1;
			}
		}
		
		System.out.println(max + " " + number);
		scan.close();
		
		
	}

}

---

3

2577

숫자의 개수

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(System.in);
		int a = scan.nextInt();
		int b = scan.nextInt();
		int c = scan.nextInt();
		int number[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
		
		String mix = Integer.toString(a*b*c);
		String zz[] = mix.split("");
		
		for(int i=0; i<mix.length(); i++) {
			switch (zz[i]) {
			case "0" : number[0]+=1; break;
			case "1" : number[1]+=1;break;
			case "2" : number[2]+=1;break;
			case "3" : number[3]+=1;break;
			case "4" : number[4]+=1;break;
			case "5" : number[5]+=1;break;
			case "6" : number[6]+=1;break;
			case "7" : number[7]+=1;break;
			case "8" : number[8]+=1;break;
			case "9" : number[9]+=1; break;
			default:
				break;
			}

		}
		
		for(int i=0; i<10; i++)
			System.out.println(number[i]);
		scan.close();
	}

}

---

4

3052

나머지

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(System.in);
		int number =10;
		int a[] = new int[number];
		int b[] = new int[number];
		int count = 10;
		for(int i= 0; i<number; i++) {		
			a[i] = scan.nextInt();
			b[i] = a[i]%42;
			for(int j=0; j<i; j++) {
				if(b[i] == b[j]) {
					count--;
					break;
				}
			}
		}
		System.out.println(count);

		scan.close();
		}
}

---

5

1546

평균

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		
		int testCount = scan.nextInt();//시험본 과목 개수
		double a[] = new double[testCount];
		for(int i=0; i<a.length; i++) {
			a[i] = scan.nextInt();
		}
		
		double M = a[0];
		for(int i=1; i<a.length; i++) {
			if(M < a[i])
				M = a[i];
		}
		
		double sum =0;
		for(int i=0; i<a.length; i++) {
			a[i] = a[i]/M*100;
			sum += a[i];
		}
		
		System.out.println(sum/testCount);
		scan.close();
	}

}

---

6

8958

OX퀴즈

import java.util.Scanner;

public class Main {

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

	  String a[] = new String [scan.nextInt()];
	  scan.nextLine();
      for(int i=0; i<a.length; i++) 
    	  a[i] = scan.nextLine();
    	  
      for(int i= 0; i<a.length; i++) {
          int score = 0;
          int sum = 0;
    	  
    	  for(int j=0; j<a[i].length(); j++) {
        	 
    		  if(a[i].charAt(j) == 'O') {
            score++;
            sum += score;
    		  }
            else score = 0;
      
         }
         System.out.println(sum);
      }
      
      scan.close();
   }
}

---

7

4344

평균은 넘겠지

import java.util.Scanner;

public class Main {

	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		//BufferedReader bfr = new BufferedReader(new InputStreamReader(System.in));
		int C = scan.nextInt(); //테스트케이스.
		
		int student[][] = new int[C][]; //학생의 수와 점수.
	

		for(int i=0; i<student.length; i++) {
			float sum = 0;
			float avg = 0;
			float count = 0;

			student[i] = new int [scan.nextInt()]; //2차원배열 동적할당 //여기서 마지막 테스트에 마지막점수 넣고 엔터안누르면 안넘어가짐
			
			for(int j=0; j<student[i].length; j++) { //행 값 구하기.
				student[i][j] = scan.nextInt();

				sum += student[i][j];
			}
			
			avg = sum / student[i].length;
			for(int z=0; z<student[i].length; z++)
				if(student[i][z] > avg) count++;
			
			float percent = (100/(float)student[i].length) * count;
			System.out.printf("%.3f", percent);
			System.out.println("%");
		}

		scan.close();
	}
}

---

마지막 6번과 7번문제는 쉽고 빠르게 풀리지 않았던 것 같다.

2차원 배열에서의 동적할당과, String 문자에서 각 글자를 배열처럼 쪼개서 판단하는 것을 다시 상기했다.

엔터를 안치면 마지막 입력이 안되어서,  마지막 단계의 scan.nextInt()은 nextLine을 한번 해줌으로써 풀었다.