Given an array of integers and a target value, determine the number of pairs of array elements that have a difference equal to the target value.

Example

There are three values that differ by : , , and . Return .

Function Description

Complete the pairs function below.

pairs has the following parameter(s):

  • int k: an integer, the target difference
  • int arr[n]: an array of integers

Returns

  • int: the number of pairs that satisfy the criterion

Input Format

The first line contains two space-separated integers and , the size of and the target value.
The second line contains space-separated integers of the array .

Constraints

  • each integer will be unique

Sample Input

STDIN       Function
-----       --------
5 2         arr[] size n = 5, k =2
1 5 3 4 2   arr = [1, 5, 3, 4, 2]

Sample Output

3

Explanation

There are 3 pairs of integers in the set with a difference of 2: [5,3], [4,2] and [3,1]. .

Line: 1 Col: 1
  1. Challenge Walkthrough
    Let's walk through this sample challenge and explore the features of the code editor.1 of 6
  2. Review the problem statement
    Each challenge has a problem statement that includes sample inputs and outputs. Some challenges include additional information to help you out.2 of 6
  3. Choose a language
    Select the language you wish to use to solve this challenge.3 of 6
  4. Enter your code
    Code your solution in our custom editor or code in your own environment and upload your solution as a file.4 of 6
  5. Test your code
    You can compile your code and test it for errors and accuracy before submitting.5 of 6
  6. Submit to see results
    When you're ready, submit your solution! Remember, you can go back and refine your code anytime.6 of 6
  1. Check your score