Pairs

Given integers, count the number of pairs of integers whose difference is .

Input Format

The first line contains and .
The second line contains numbers of the set. All the numbers are unique.

Constraints

• Each integer will be greater than and at least smaller than .

Output Format

An integer that tells the number of pairs of integers whose difference is .

Sample Input

5 2  
1 5 3 4 2  

Sample Output

3

Explanation

There are 3 pairs of integers in the set with a difference of 2.

Java code:
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
    static int pairs(int[] a,int k) {
      /* Complete this function */
        Arrays.sort(a);
        int i=a.length-1;
        int j=i-1,c=0;
        while(j>=0)
        {
            if(a[i]-a[j]<k)
                j--;
            else if(a[i]-a[j]>k)
                i--;
            else if(a[i]-a[j]==k)
            {
                c++;
                j--;
            }
               
        }
        return c;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int res;
       
        String n = in.nextLine();
        String[] n_split = n.split(" ");
       
        int _a_size = Integer.parseInt(n_split[0]);
        int _k = Integer.parseInt(n_split[1]);
       
        int[] _a = new int[_a_size];
        int _a_item;
        String next = in.nextLine();
        String[] next_split = next.split(" ");
       
        for(int _a_i = 0; _a_i < _a_size; _a_i++) {
            _a_item = Integer.parseInt(next_split[_a_i]);
            _a[_a_i] = _a_item;
        }
       
        res = pairs(_a,_k);
        System.out.println(res);
    }
}