Update pair.cpp

Input Format:

1st line contains N & K (integers).
2nd line contains N numbers of the set. All the N numbers are assured to be distinct.

Output Format:

One integer saying the no of pairs of numbers that have a diff K.

Sample Input #00:

5 2
1 5 3 4 2

Sample Output #00:

3

Sample Input #01:

10 1
363374326 364147530 61825163 1073065718 1281246024 1399469912 428047635 491595254 879792181 1069262793 

Sample Output #01:

0