백준1940

https://www.acmicpc.net/problem/1940

import java.util.Arrays;
import java.util.Scanner;

public class Baek1940 {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();

    int arr[] = new int[n];
    int count = 0;
    for (int i = 0; i < n; i++) {
      arr[i] = sc.nextInt();
    }

    Arrays.sort(arr);
    for (int i = 0; i < arr.length; i++) {
      System.out.println("arr" + i + "=" + arr[i]);
    }

    int left = 0;
    int right = n - 1;

    while (left < right) {
      if (arr[left] + arr[right] == m) {
        count++;
        left++;
        right--;
      } else if (arr[left] + arr[right] < m) {
        left++;
      } else {
        right--;
      }
    }
    System.out.println(count);
  }
}