https://github.com/nfriedly/stripe-ctf-2014-level0

A simple Big-O reduction
https://github.com/nfriedly/stripe-ctf-2014-level0

Last synced: 17 days ago
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A simple Big-O reduction

• Host: GitHub
• URL: https://github.com/nfriedly/stripe-ctf-2014-level0
• Owner: nfriedly
• Created: 2014-02-03T15:21:32.000Z (almost 11 years ago)
• Default Branch: master
• Last Pushed: 2014-02-03T15:22:22.000Z (almost 11 years ago)
• Last Synced: 2024-10-12T16:22:45.030Z (about 1 month ago)
• Language: Python
• Homepage: https://stripe-ctf.com/
• Size: 234 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Level 0

## Usage

To submit your code, first commit, and then run `git push`.

Only the program input will vary; we'll always run against the same

dictionary (`test/harness` will download that dictionary for you if

you don't have it).

See https://stripe-ctf.com for context on this level.

## Observations

It's hard to know what this script does, but it seems to take time

depending on the size of the input:

    $ time ./level0 < short.txt >/dev/null

    real  0m1.231s

    user  0m1.132s

    sys   0m0.096s

Compare to:

    $ time ./level0 < long.txt >/dev/null

    real  0m14.060s

    user  0m12.952s

    sys   0m1.104s

`wc -c` shows that long.txt is about 10 times larger than short.txt,

so it seems like the runtime grows linearly with input size. Since it

also has to read the entire input, there's not going to be a way to do

better than a linear-time solution.

## Catalog

- `build.sh`: We'll run this file before trying to run your code. This

  is likely only relevant if you rewrite in another language, but it

  also could be useful for something like fetching dependencies via

  Bundler. Feel free to modify it arbitarily; we'll run the modified

  version on our build servers. (https://stripe-ctf.com/about#build

  has more information on the build process.)

- `level0`: The mysterious program. Why so slow?

- `long.txt`: An example long input file.

- `short.txt`: An example short input file.

- `README.md`: This file :).

- `test/*`: A framework to make it easy for you to run test cases

  locally. You should only ever have to run `test/harness`.