BufferedReader와 BufferedWriter를 이용한 별찍기 문제

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
 
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 line = 0;
        line = Integer.parseInt(br.readLine());
        int star = line;
        int space = 0;
        if (line >= 1 && line <= 100) {
            for (int j = 0 ; j < line; j++) {
                for (int i = 0 ; i < space;i++) {
                    bw.write(" ");
                }
                for (int i = 0 ; i < star;i++) {
                    bw.write("*");
                }
                for (int i = 0 ; i < star-1;i++) {
                    bw.write("*");
                }
                bw.write("\n");
                if (j != line-1) {
                star --; 
                space ++;
                }else {
                star ++;
                space --;
                }
            }
            for (int j = 0 ; j < line - 1; j++) {
                for (int i = 0 ; i < space ;i++) {
                    bw.write(" ");
                }
                for (int i = 0 ; i < star;i++) {
                    bw.write("*");
                }
                for (int i = 0 ; i < star - 1;i++) {
                    bw.write("*");
                }
                bw.write("\n");
                if (j != line-2) {
                    star ++;
                    space --;
                }
            }
            bw.flush();
            bw.close();
            br.close();
        }
    }        
}
 

 

실행결과 

 

예로 '11'을 입력