Problem Statement:
Given N numbers , [N<=10^5] we need to count the total pairs of
numbers that have a difference of K. [K>0 and K<1e9]
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
Note: Java/C# code should be in a class named "Solution"
Read input from STDIN and write output to
STDOUT.
------------------------code-----------------------------------------
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
public class Solution {
public static void main(String[] args) {
Scanner br=new Scanner(System.in);
int N = br.nextInt();
int K = br.nextInt();
int[] array = new int[N];
int count = 0;
Map map = new HashMap();
for (int i = 0 ; i < N ; i++ ){
array[i] = br.nextInt();
if(map.get(array[i])==null){
map.put(array[i],1);
}
else{
map.put(array[i],map.get(array[i])+1);
}
}
for(int i = 0 ; i < N ; i++ ){
if(map.get(array[i]+K)!=null){
count+=map.get(array[i]+K);
}
}
System.out.println(count);
}
}