76 lines
2.4 KiB
Markdown
76 lines
2.4 KiB
Markdown
# Secret Handshake
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> There are 10 types of people in the world: Those who understand
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> binary, and those who don't.
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You and your fellow cohort of those in the "know" when it comes to
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binary decide to come up with a secret "handshake".
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```text
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1 = wink
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10 = double blink
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100 = close your eyes
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1000 = jump
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10000 = Reverse the order of the operations in the secret handshake.
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```
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Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.
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Here's a couple of examples:
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Given the input 3, the function would return the array
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["wink", "double blink"] because 3 is 11 in binary.
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Given the input 19, the function would return the array
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["double blink", "wink"] because 19 is 10011 in binary.
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Notice that the addition of 16 (10000 in binary)
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has caused the array to be reversed.
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Run the tests with:
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```bash
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bats secret_handshake_test.sh
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```
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After the first test(s) pass, continue by commenting out or removing the
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`[[ $BATS_RUN_SKIPPED == true ]] || skip`
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annotations prepending other tests.
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To run all tests, including the ones with `skip` annotations, run:
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```bash
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BATS_RUN_SKIPPED=true bats secret_handshake_test.sh
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```
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## Source
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Bert, in Mary Poppins [http://www.imdb.com/title/tt0058331/quotes/qt0437047](http://www.imdb.com/title/tt0058331/quotes/qt0437047)
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## External utilities
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`Bash` is a language to write "scripts" -- programs that can call
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external tools, such as
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[`sed`](https://www.gnu.org/software/sed/),
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[`awk`](https://www.gnu.org/software/gawk/),
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[`date`](https://www.gnu.org/software/coreutils/manual/html_node/date-invocation.html)
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and even programs written in other programming languages,
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like [`Python`](https://www.python.org/).
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This track does not restrict the usage of these utilities, and as long
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as your solution is portable between systems and does not require
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installation of third party applications, feel free to use them to solve
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the exercise.
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For an extra challenge, if you would like to have a better understanding
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of the language, try to re-implement the solution in pure `Bash`,
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without using any external tools. Note that there are some types of
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problems that bash cannot solve, such as performing floating point
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arithmetic and manipulating dates: for those, you must call out to an
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external tool.
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## Submitting Incomplete Solutions
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It's possible to submit an incomplete solution so you can see how others
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have completed the exercise.
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