public class Solution
extends Object
2006 - Count Number of Pairs With Absolute Difference K\.
Easy
Given an integer array `nums` and an integer `k`, return _the number of pairs_ `(i, j)` _where_ `i < j` _such that_ `|nums[i] - nums[j]| == k`.
The value of `|x|` is defined as:
* `x` if `x >= 0`.
* `-x` if `x < 0`.
**Example 1:**
**Input:** nums = [1,2,2,1], k = 1
**Output:** 4
**Explanation:** The pairs with an absolute difference of 1 are:
- [**1** , **2** ,2,1]
- [**1** ,2, **2** ,1]
- [1, **2** ,2, **1** ]
- [1,2, **2** , **1** ]
**Example 2:**
**Input:** nums = [1,3], k = 3
**Output:** 0
**Explanation:** There are no pairs with an absolute difference of 3.
**Example 3:**
**Input:** nums = [3,2,1,5,4], k = 2
**Output:** 3
**Explanation:** The pairs with an absolute difference of 2 are:
- [**3** ,2, **1** ,5,4]
- [**3** ,2,1, **5** ,4]
- [3, **2** ,1,5, **4** ]
**Constraints:**
* `1 <= nums.length <= 200`
* `1 <= nums[i] <= 100`
* `1 <= k <= 99`