# Run Length Encoding Implement run-length encoding and decoding. Run-length encoding (RLE) is a simple form of data compression, where runs (consecutive data elements) are replaced by just one data value and count. For example we can represent the original 53 characters with only 13. ``` "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWB" -> "12WB12W3B24WB" ``` RLE allows the original data to be perfectly reconstructed from the compressed data, which makes it a lossless data compression. ``` "AABCCCDEEEE" -> "2AB3CD4E" -> "AABCCCDEEEE" ``` For simplicity, you can assume that the unencoded string will only contain the letters A through Z (either lower or upper case) and whitespace. This way data to be encoded will never contain any numbers and numbers inside data to be decoded always represent the count for the following character. ## Setup There are two different methods of getting set up to run the tests with Objective-C: - Create an Xcode project with a test target which will run the tests. - Use the ruby gem `objc` as a test runner utility. Both are described in more detail here: http://exercism.io/languages/objective-c ### Submitting Exercises When submitting an exercise, make sure your solution file is in the same directory as the test code. For example, if you're submitting `Bob.m` for the Bob exercise, the submit command would be something like `exercism submit /objective-c/bob/Bob.m`. ## Source Wikipedia [https://en.wikipedia.org/wiki/Run-length_encoding](https://en.wikipedia.org/wiki/Run-length_encoding) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.