public class Solution {

public int findPairs(int[] nums, int k) {

if (nums == null || nums.length == 0 || k < 0) return 0;

```
int count=0;
int l=0;
int r=0;
int size= nums.length;
Arrays.sort(nums);
while(r<size){
while(r+1<size && nums[r] == nums[r+1]) {
r++;
}
if(nums[r]-nums[l]==k && r!=l){
l++; r++;
count += 1;}
else if(nums[r]-nums[l]>k)
{
l++;
}
else{
r++;
}
}
return count;
}
```

}