[java/BOJ] sw코딩멘토링 - 2444, 2445, 10811, 10991

https://www.notion.so/33ca624f1b088037a909c0c743cc62ed

객체지향프로그래밍의 특징 | Notion

 

 

2444 - 별 찍기-7

https://www.acmicpc.net/problem/2444

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        int cnt = n-1;
        int cnt2 = 1;
        //증가
        for(int i = 1; i<n; i++) {
            for(int j = 0; j<cnt; j++) {
                System.out.print(" ");
            }
            for(int j = 0; j<cnt2; j++) {
                System.out.print("*");
            }
            cnt--;
            cnt2+=2;
            System.out.println("");
        }
        
        //가운데
        for(int i = 0; i<(2*n-1); i++) {
            System.out.print("*");
        }
        
        System.out.println("");
        
        //cnt = 1
        //cnt2 = 7
        //감소
        cnt++;
        cnt2-=2;
        for(int i = 1; i<n; i++) {
            for(int j = 0; j<cnt; j++) {
                System.out.print(" ");
            }
            for(int j = 0; j<cnt2; j++) {
                System.out.print("*");
            }
            cnt++;
            cnt2-=2;
            System.out.println("");
        }
        
        
        
    }
}

 

 

 

2445 - 별 찍기-8

https://www.acmicpc.net/problem/2445

import java.util.Scanner;



public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        for(int i = 1; i<=n; i++) {
            for(int j = 1; j<=i; j++) {
                System.out.print("*");
            }
            for(int k = 1; k<=2*(n-i); k++) {
                System.out.print(" ");
            }
            for(int j=1; j<=i; j++) {
                System.out.print("*");
            }
            System.out.println();
        }
        
        
        for(int i=n-1; i>0; i--) {
            for(int j=1; j<=i; j++) {
                System.out.print("*");
            }
            for(int k=1; k<=2*(n-i); k++) {
                System.out.print(" ");
            }
            for(int j=1; j<=i; j++) {
                System.out.print("*");
            }
            System.out.println();     
        }
        
        s.close();
    }
}

import java.util.Scanner;


public class Main {
    
    
    
    //static 함수를 선언할 수도 있음(객체 생성 생략)
    public void asta(int i) {
        for(int j=1; j<=i; j++) {
                System.out.print("*");
            }
    }
    public void spac(int i, int n) {
    	for(int k = 1; k<=2*(n-i); k++) {
                System.out.print(" ");
            }
    }
    
    
    
    public static void main(String[] args) {

        Main m = new Main();
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        for(int i = 1; i<=n; i++) {
            m.asta(i);
			m.spac(i,n); 
            m.asta(i);
            
            System.out.println();
        }
        
        
        for(int i=n-1; i>0; i--) {
            m.asta(i);
            m.spac(i,n);
            m.asta(i);
            
            System.out.println();     
        }
        
        s.close();
    }
}

 

 

10811 - 바구니 뒤집기

https://www.acmicpc.net/problem/2445

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        int m = s.nextInt();
        int[] ary = new int[n+1]; //0번째는 안쓴다
        
        for(int k=1; k<=n; k++) {
            ary[k] = k;
        }
        
        for(int k=1; k<=m; k++) {
            int i = s.nextInt();
            int j = s.nextInt();
            
            //역순
            while(i<j) {
                int dummy = ary[i];
                ary[i] = ary[j];
                ary[j] = dummy;
                i++;
                j--;
            }
        }
        
        for(int k = 1; k<=n; k++) {
            System.out.print(ary[k]+" ");
        }
        
        s.close();
    }
}

 

 

10991. 별 찍기 - 16

https://www.acmicpc.net/problem/10991

import java.util.Scanner;

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