 Pairs with difference k
##### Submissions: 5869   Accuracy: 28.89%   Difficulty: Easy   Marks: 2

Given an array A of N positive integers. Find the number of pairs of integers whose difference is equal to a given number K.
Note: (a, b) and (b, a) are considered same. Also, same numbers at different indices are considered different.

Input:
The first line of the input contains T denoting the total number of testcases. Then follows the description of testcases. The first line of each testcase contains two space separated positive integers N and K denoting the size of array and the value of K. The second line contains N space separated positive integers denoting the elements of array.

Output:
Output the number of pairs having difference equal to K in a separate line.

Constraints:
1 <= T <= 100
1 <= N <= 100
1 <= K <= 100
1 <= Ai <= 1000

Example:
Input:
2
5 2
6 4 5 8 7
4 2
1 3 1 8
Output:
3
2

Explanation:
Testcase 1: (6, 4), (5, 7) and (6, 8) are pairs with difference 2.

#### ** For More Input/Output Examples Use 'Expected Output' option **

Author: atharv

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