Semordnilap

Category: Strings

Difficulty: Easy

Description

Write a function that takes in a list of unique strings and returns a list of semordnilap pairs.

A semordnilap pair is defined as a set of different strings where the reverse of one word is the same as the forward version of the other. For example the words "diaper" and "repaid" are a semordnilap pair, as are the words "palindromes" and "semordnilap".

The order of the returned pairs and the order of the strings within each pair does not matter.

Sample Input

words = ["diaper", "abc", "test", "cba", "repaid"]

Sample Output

[["diaper", "repaid"], ["abc", "cba"]]

Optimal Space & Time Complexity

O(n * m) time | O(n * m) space - where n is the number of words and m is the length of the longest word