65 lines
2.7 KiB
Markdown
65 lines
2.7 KiB
Markdown
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# Problem Statement
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You are a member of the flight software team at Umbra and are responsible
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for writing code that manages the satellite’s propulsion system.
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Firing the propulsion system involves waiting for a certain period of time before ignition.
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The following is an example usage of this system:
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* At absolute time t = 0, send a command to the computer to fire the propulsion in 15 seconds
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* At absolute time t = 2, send a command to the computer to fire the propulsion in 30 seconds
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* At absolute time t = 32, the computer begins firing the propulsion
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The flight computer should accept a command with a relative time of when to fire
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the propulsion - once that time has elapsed, the program should print out “firing now!”.
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If another command is received before the propulsion is fired then the most recently
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received relative time should overwrite any existing commands.
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More formally, if a command _A_ is waiting to fire and another command _B_ is received
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before A has fired, then B should replace _A_ as the pending command and _A_ should never fire.
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If a time of -1 is given, any outstanding commands to fire the propulsion are cancelled.
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Note that the flight computer should be able to fire the thruster multiple times in a
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single execution of the program.
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You may use exactly one of the following interfaces for getting data into and out of your program:
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* Standard input/standard output
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* TCP
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You can use whichever is more convenient - we note that some languages make asynchronous
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IO with standard input/standard output cumbersome and have thus included TCP.
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If you do choose to use TCP, please have your server listen on port `8124`.
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A sample TCP client, `propulsion_tcp_client.py`, is provided that plumbs standard input
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to TCP writes and likewise plumbs TCP reads to standard output.
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Commands should be delineated by newlines.
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A sample _complete_ execution of your program using standard input and output is shown below
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```
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./your_program
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15
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30
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firing now!
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```
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# Submitting your code
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You may complete this assignment in any programming language that you wish.
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We're most familiar with Rust and Python at Umbra, but we always enjoy learning
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new languages and seeing solutions with different tools!
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Your final submission for this exercise should be a zip file including:
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* The source code of your program.
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* A brief README with a description of your approach and instructions on how to
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build and run the program.
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* Any libraries or frameworks needed to run your program, or instructions for installing them.
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Please ensure that your code is clear and legible before submitting.
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While we don't expect you to write production-quality code for this exercise,
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readability goes a long way in helping us review your submission.
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