[Java/Algorithm] 백준-10951 EOF 사용하기 + 성능비교

EOF 란?

End of File, 더이상 데이터가 존재하지 않을 경우 반복문을 종료하는 것.

ctrl + Z(윈도우) 
ctrl + D(리눅스) 로 종료

3가지 방법이 있다.

1. BufferedReader + StringTokenizer
2. BufferedReader + String.charAt()
3 .Scanner

 

1. BufferedReader + StringTokenizer

import java.io.*;
import java.util.StringTokenizer;

public class Main
{	
	public static void main(String[] args) throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		StringTokenizer st;
		String str;
		
		while((str=br.readLine()) !=null) {
			st = new StringTokenizer(str, " ");
			int a = Integer.parseInt(st.nextToken());
			int b = Integer.parseInt(st.nextToken());
			
			sb.append(a+b).append("\n");
		}
		
		System.out.println(sb);
	}
	
}

 

2. BufferedReader + String.charAt()

import java.io.*;

public class Main
{	
	public static void main(String[] args) throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		String str;
		
		while((str=br.readLine()) !=null) {
			int a = str.charAt(0) - 48;
			int b = str.charAt(2) - 48;
			
			sb.append(a+b).append("\n");
		}
		
		System.out.println(sb);
	}
	
}

 

3. Scanner

import java.io.*;
import java.util.Scanner;

public class Main
{	
	public static void main(String[] args) throws IOException
	{
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		while(sc.hasNext()) {
			int a = sc.nextInt();
			int b = sc.nextInt();
			
			sb.append(a+b).append("\n");
		}
		System.out.println(sb);
	}
	
}

 

성능비교

위부터 순서대로
Scanner
BufferedReader +  String.charAt()
BufferedReader + StringTokenizer