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