In this practice challenge, you will get an opportunity to use the Data Structures and Algorithms skills you have built over the course of the program. It will also help you prepare for the types of challenges you can expect to see in job interviews.

Create a method #fix_the_string that takes a string value as input and returns a "fixed" version of the string.

The input string will consist of uppercase and lowercase letters. To "fix" the string, your algorithm will need to identify and remove any adjacent pairs of characters in which:

• the characters are the same letter, and
• one is uppercase and the other is lowercase

This process should be repeated until there are no adjacent pairs of the same uppercase and lowercase characters. Once all the "bad" pairs of characters have been removed, your method should return the fixed string.

Examples:

fix_the_string('AaalgoOorithmsS')
# => "algorithm"

fix_the_string('abBAC')
# => "C"

fix_the_string('')
# => ""

Remember the process:

1. Rewrite the problem in your own words
2. Write your own test cases
3. Pseudocode
4. Code
5. Refactor to make it clean and readable
6. Refactor to optimize

Once you have a complete solution, run the test suite using learn test as a final check.

Several possible approaches for completing this challenge are provided in a separate lesson. Once your code is working and you have all the tests passing, be sure to take a look at the example solutions provided. This will give you exposure to different approaches for solving this challenge, and may also give you ideas for how you might want to refactor your code to make it better.