[백준] 10871번 : X보다 작은 수 - 2 - Java

https://www.acmicpc.net/problem/10871

10871번: X보다 작은 수

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풀이

1. Scanner + Array

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
    
        Scanner in = new Scanner(System.in);
        
        //첫 번째 줄
        int N = in.nextInt();
        int X = in.nextInt();
        
        //두 번째 줄
        int arr[] = new int[N];
        for (int i = 0; i < N; i++) {
            arr[i] = in.nextInt();
        }
        in.close();
        
        for (int i = 0; i < N; i++) {
            if (arr[i] < X) {
                System.out.print(arr[i] + " ");
            }
        }
    }
}

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2. BufferedReader + StringBuilder

import java.util.Scanner;

public class Main { 
    public static void main(String[] args) {
    
        Scanner in = new Scanner(System.in);
        //첫 번째 줄
        int N = in.nextInt();
        int X = in.nextInt();
        
        //두 번째 줄
        StringBuilder sb = new StringBuilder();
        for(int i = 0 ; i < N ; i++) {
            int value = in.nextInt();
            
            if(value < X) {
                sb.append(value + " ");
            }
        }
        System.out.println(sb);	
    }
}

 

3. BufferedReader + StringTokenizer + StringBuilder

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.StringTokenizer;
 
public class Main {
    public static void main(String[] args) throws IOException {
    
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        //첫 번째 줄
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        int N = Integer.parseInt(st.nextToken());
        int X = Integer.parseInt(st.nextToken());
 
        //두 번째 줄 
        StringBuilder sb = new StringBuilder();
        st = new StringTokenizer(br.readLine(), " ");
		
        for (int i = 0; i < N; i++) {
            int value = Integer.parseInt(st.nextToken());
 
            if (value < X) {
                sb.append(value).append(' ');
            }
        }
        System.out.println(sb);
    }
}

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성능

• BufferedReader > Scanner

 

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출처 : https://st-lab.tistory.com/38