63 lines
2.4 KiB
Markdown
63 lines
2.4 KiB
Markdown
# Run Length Encoding
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Implement run-length encoding and decoding.
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Run-length encoding (RLE) is a simple form of data compression, where runs
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(consecutive data elements) are replaced by just one data value and count.
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For example we can represent the original 53 characters with only 13.
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```
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"WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWB" -> "12WB12W3B24WB"
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```
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RLE allows the original data to be perfectly reconstructed from
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the compressed data, which makes it a lossless data compression.
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```
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"AABCCCDEEEE" -> "2AB3CD4E" -> "AABCCCDEEEE"
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```
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For simplicity, you can assume that the unencoded string will only contain
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the letters A through Z (either lower or upper case) and whitespace. This way
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data to be encoded will never contain any numbers and numbers inside data to
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be decoded always represent the count for the following character.
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## Rust Installation
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Refer to the [exercism help page][help-page] for Rust installation and learning
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resources.
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## Writing the Code
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Execute the tests with:
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```bash
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$ cargo test
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```
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All but the first test have been ignored. After you get the first test to
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pass, remove the ignore flag (`#[ignore]`) from the next test and get the tests
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to pass again. The test file is located in the `tests` directory. You can
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also remove the ignore flag from all the tests to get them to run all at once
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if you wish.
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Make sure to read the [Crates and Modules](https://doc.rust-lang.org/stable/book/crates-and-modules.html) chapter if you
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haven't already, it will help you with organizing your files.
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## Feedback, Issues, Pull Requests
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The [exercism/xrust](https://github.com/exercism/xrust) repository on GitHub is the home for all of the Rust exercises. If you have feedback about an exercise, or want to help implement new exercises, head over there and create an issue. Members of the [rust track team](https://github.com/orgs/exercism/teams/rust) are happy to help!
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If you want to know more about Exercism, take a look at the [contribution guide](https://github.com/exercism/x-common/blob/master/CONTRIBUTING.md).
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[help-page]: http://exercism.io/languages/rust
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[crates-and-modules]: http://doc.rust-lang.org/stable/book/crates-and-modules.html
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## Source
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Wikipedia [https://en.wikipedia.org/wiki/Run-length_encoding](https://en.wikipedia.org/wiki/Run-length_encoding)
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## Submitting Incomplete Problems
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It's possible to submit an incomplete solution so you can see how others have completed the exercise.
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