The Dance Partners

Dance pairs work best when heights are close. The teacher counts the workable pairs. 💃🕺

You get the heights and the max difference d. Print how many pairs of dancers differ by at most d.

Example:

Input: heights = [120, 125, 140, 122], d = 5 Output: 3

Checking every pair, the differences are 5, 20, 2, 15, 3, 18 — three of them (5, 2, 3) are at most 5.