[백준]2739번:구구단 - java 풀이

 

BufferedReader +  StringBuilder 풀이)

 

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();
        
		StringBuilder sb = new StringBuilder();
		
		for(int i=1; i<=9; i++ ) {
			sb.append(N+" * "+i+" = "+N*i+"\n");
		}
		System.out.println(sb);
	}
}

 

 

 

 

 

 

BufferedReader + BufferedWriter 풀이)

 

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));
		
		int N = Integer.parseInt(br.readLine());
		br.close();
		
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		
		for(int i=1; i<=9; i++ ) {
			bw.write(N+" * "+i+" = "+N*i+"\n");
		}
		bw.flush();
		bw.close();
	}
}

 

 

가장 기본적인 방법은 반복문 안에 System.out.println(N+" * "+i+" = "+N*i); 을 써주는건데

System.out.println은 StringBuilder나 BufferedWriter에 성능이 좋지 않기 때문에 여러번 반복되는 경우 사용하지 않는것이 좋다고 한다.