2439 별 찍기 - 2

* BufferedReader, StringBuilder, 상수

import java.io.*;

public class Main {
	public static final String LINNER = "\n";
	public static final String BLANK = " ";
	
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder star = new StringBuilder();
		StringBuilder result = new StringBuilder();
		int num = Integer.parseInt(br.readLine());
		br.close();
		
		for(int i=1; i<=num; i++) {
			StringBuilder blank = new StringBuilder();
			star.append("*");
			for(int j=num-i; j>0; j--) {
				blank.append(BLANK);
			}
			result.append(blank);
			result.append(star);
			result.append(LINNER);
		}
		System.out.print(result);
	}
}

더 빠르고 직관적인 로직

* BufferedReader, StringBuilder

  - StringBuilder 생성을 적게하고 가독성이 좋다

import java.io.*;
 
public class Main {
 
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int N = Integer.parseInt(br.readLine());
		br.close();
 
		StringBuilder sb = new StringBuilder();
 
		for (int i = 1; i <= N; i++) {
			for (int j = 1; j <= N - i; j++) {
				sb.append(' ');
			}
			for (int k = 1; k <= i; k++) {
				sb.append('*');
			}
			sb.append('\n');
		}
		System.out.print(sb);
	}
}