Introduction

Welcome to our focused exploration of Ruby's Set and its remarkable applications in solving algorithmic challenges. In this lesson, "Mastering Unique Elements and Anagram Detection with Ruby Set", we'll delve into how this efficient data structure can be leveraged to address and solve various problems commonly encountered in technical interviews.

Problem 1: Unique Echo

Picture this: you're given a vast list of words, and you must identify the final word that stands proudly solitary — the last word that is not repeated. Imagine sorting through a database of unique identifiers and finding one identifier towards the end of the list that is unlike any other.

Naive Approach

The straightforward approach would be to examine each word in reverse, comparing it to every other word for uniqueness. This brute-force method would result in poor time complexity, O(n^2), which is less than ideal for large datasets.

Here is the naive approach in Ruby:

Efficient Approach

We can utilize two Set instances: words_set to maintain unique words and duplicates_set to keep track of duplicate words. By the end, we can remove all duplicated words from to achieve our goal.

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