count-number-of-pairs-with-absolute-difference-k

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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)wherei < jsuch 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

Related Topics

[Array] [Hash Table] [Counting]

Hints

Hint 1

Can we check every possible pair?

Hint 2

Can we use a nested for loop to solve this problem?