Count such pairs in array whose sum is equal to particular number

 Count such pairs in array whose sum is equal to particular number

Description

You are given an array A of N integers along with a target integer. Your task is to find out the number of pairs of integers present in the array whose sum is equal to the target value.

Input

Input Format :

First line contains 2 integers: N and the target respectively.

Second line contains N integers which are the elements of the array.

Constraints :

N<100

Output

Print one number which is number of such pairs.

Sample Input 1 

5 9
3 0 6 2 7

Sample Output 1

2

import java.util.Scanner;

public class Main {

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

        for (int i =0;i<len;i++){
            arr[i]=sc.nextInt();
        }
        int count = 0;
        for (int j = 0 ; j< len; j++){
            for (int k = 0;k<len;k++){
                if(arr[j]+arr[k]==sum && j!=k){
                    count++;
                }
            }
        }
        System.out.println(count/2);

    }
}