[BOJ] 26091 현대모비스 소프트웨어 아카데미 (JAVA)

https://www.acmicpc.net/problem/26091

26091번: 현대모비스 소프트웨어 아카데미

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

public class Main {
	
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        int N = Integer.parseInt(st.nextToken());
        int M = Integer.parseInt(st.nextToken());
        int[] arr = new int[N];
        st = new StringTokenizer(br.readLine(), " ");
        for (int i = 0; i < N; i++) {
            arr[i] = Integer.parseInt(st.nextToken());
        } // end of input

        Arrays.sort(arr);
        int head = 0;
        int tail = N - 1;
        int cnt = 0;

        while (head < tail) {
            int num = arr[head] + arr[tail];
            if (M <= num) {
                cnt++;
                head++;
                tail--;
            } else head++;
        }

        System.out.print(cnt);

    }
	
}