Challenge: Find Symmetric Pairs in a List

Statement

Given a list of pairs, nums, find all the symmetric pairsBy definition, (a, b) and (c, d) are symmetric pairs iff, a = d and b = c. from it. If no symmetric pair is found, return an empty list. The first element of each pair is guaranteed to be distinct.

The output can be in any order, and returning any one symmetric pair is acceptable.

Constraints:

• $2 \leq$ nums.length $\le 10^3$ ...