Challenge: Find Symmetric Pairs in an Array

Problem Statement #

By definition, (a, b) and (c, d) are symmetric pairs iff, a = d and b = c. In this problem, you have to implement the findSymmetric(list) function which will find all the symmetric pairs in the ​given array.

Input #

An array of pairs. The first element of each pair would be unique.

Output #

An array containing all the symmetric pairs of integers in the input array.

Sample Input #

var list = [[1, 2], [3, 4], [5, 9], [4, 3], [9, 5]]

Sample Output #

[[3, 4], [4, 3], [5, 9], [9, 5]]