https://www.acmicpc.net/problem/2438
문제
풀이
👉 기본적인 방법
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
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();
for (int i=1; i<=n; i++) {
for (int j=1; j<=i; j++)
System.out.print("*");
System.out.println();
}
}
}
👉 String.repeat()
repeat() 메소드는 "*".repeat(i) → *를 i번 반복한 문자열을 생성하여 반환한다.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
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();
for (int i=1; i<=n; i++)
System.out.println("*".repeat(i));
}
}
👉 BufferedWriter
출력할 문자들이 많아지면 많아질수록 다른 출력 방법들에 비해 매우 우수한 성능을 보여준다.
import java.io.*;
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 n = Integer.parseInt(br.readLine());
br.close();
for (int i=1; i<=n; i++) {
bw.write("*".repeat(i));
bw.newLine();
}
bw.flush();
bw.close();
}
}
실행 결과