[1일 1문제] 백준 단계별로 풀어보기 4, 1-4번 (2.5~2.9)

2.5

문제번호 2563

package baekjoon;

import java.util.Scanner;

public class java_0205 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int[][] a = new int [101][101];
		int area = 0;
		
		for(int i = 0; i < num; i++) {
			int x = sc.nextInt();
			int y = sc.nextInt();
			
			for(int j = 0; j < 10; j++) {
				for(int k = 0; k < 10; k++) {
					a[x+j][y+k] = 1;
				}
			}
		}
		
		for(int l = 0; l < 101; l++) {
			for(int n = 0; n <101; n++) {
				if(a[l][n] == 1) {
					area += 1;
				}
			}
		}
		System.out.println(area);
		
		sc.close();
	}
}

 

2.6

문제번호 2745

package baekjoon;

import java.util.Scanner;

public class java_0206 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		String num = sc.next();
		int N = sc.nextInt();
		int tmp = 1;
		int result = 0;
		
		for(int i = num.length()-1; i >= 0; i--) {
			char b = num.charAt(i);
			
			if('A' <= b && b <= 'Z') {
				result += (b-'A'+10) * tmp;
			} else {
				result += (b-'0') * tmp;
			}
			tmp *= N;
		}
		System.out.println(result);
		sc.close();
	}
}

 

2.7

문제번호 11005

package baekjoon;

import java.util.ArrayList;
import java.util.Scanner;

public class java_0207 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int N = sc.nextInt();
		
		ArrayList<Character> list = new ArrayList<>();
		
		while(num>0) {
			if(num % N < 10) {
				list.add((char)(num % N + '0'));
			} else {
				list.add((char)(num % N - 10 + 'A'));
			}
			num /= N;
		}
		
		for(int i = list.size()-1; i >= 0; i--) {
			System.out.print(list.get(i));
		}
		sc.close();
	}
}

 

2.8

문제번호 2720

package baekjoon;

import java.util.Scanner;

public class java_0208 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] C = new int[N];
		
		for(int i = 0; i < N; i++) {
			C[i] = sc.nextInt();
		}
		
		for(int i = 0; i < N; i++) {
			int quarter = 0;
			int dime = 0;
			int nickel = 0;
			int penny = 0;
			
			quarter = C[i] / 25;
			C[i] %= 25;
			dime = C[i] / 10;
			C[i] %= 10;
			nickel = C[i] / 5;
			C[i] %= 5;
			penny = C[i];
			
			System.out.println(quarter + " " + dime + " " + nickel + " " + penny);
		}
		
		sc.close();
	}
}

 

2.9

문제번호 2903

package baekjoon;

import java.util.Scanner;

public class java_0209 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int dot = (int)Math.pow(2, n) + 1;
		System.out.println(dot*dot);
		sc.close();
	}
}