[백준/자바] 10871 - X보다 작은 수

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());

        int n = Integer.parseInt(st.nextToken());
        int x = Integer.parseInt(st.nextToken());

        List<Integer> list = new ArrayList<>();
        st = new StringTokenizer(br.readLine());
        for(int i=0; i<n; i++) {
            int num = Integer.parseInt(st.nextToken());
            if(num < x) list.add(num);
        }

        for(int i=0; i < list.size() - 1; i++) {
            System.out.print(list.get(i) + " ");
        }
        System.out.print(list.get(list.size() - 1));

        br.close();
    }
}

 

리스트에 값을 담고 출력한다.

 

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import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());

        int n = Integer.parseInt(st.nextToken());
        int x = Integer.parseInt(st.nextToken());

        StringBuilder sb = new StringBuilder();
        st = new StringTokenizer(br.readLine());
        for(int i=0; i<n; i++) {
            int num = Integer.parseInt(st.nextToken());
            if(num < x) sb.append(num).append(" ");
        }

        System.out.println(sb);

        br.close();
    }
}

  

StringBuilder로 값을 담고 출력한다.

더 효율적인 방법