Problem 907. Now! (Anticheating version 1)

Created by Óscar

Solve Later

By now, Problem 901. Now! has not been solved without the use of cheats or hacks.

http://www.mathworks.com/matlabcentral/cody/problems/901-now

The goal of this Problem is to progressively design an anticheating test suite by learning from the solutions proposed by solvers of previous problems in the Now! series.

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Solution Stats

123 Solutions
14 Solvers

Last Solution submitted on Jan 02, 2020

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8 Comments

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Jean-Marie Sainthillier on 20 Aug 2012

Difficult without a clue

Óscar on 23 Aug 2012

Everything is in memory

Óscar on 6 Sep 2012

Everything is IN MEMory

J.R.! Menzinger on 22 Nov 2012

So I found a way... and I think it was tricky, bun funny! ;-)

Jean-Marie Sainthillier on 30 Nov 2012

I don't know how to use your CLUE in practice.

Jean-Marie Sainthillier on 2 Dec 2012

Is it possible to modify the code link directly in memory ?
The test code is impressive.

Óscar on 2 Dec 2012

Congrats, you found a way... but not the one I was expecting. Someone called "game" is preventing you from passing the test suite. "game" is somehow stored in memory (see "inmem"). Try unloading it. Hope this helps

Frequency Domain on 23 Jul 2013

Try this one:
"Problem 1745 Get me!"

Solution Comments

Solution 184561

2 Comments

2 Comments

Tom Holz on 2 Jan 2013

This is Solution 184498 rewritten for size.

Frequency Domain on 23 Jul 2013

I liked the idea of deleting game.p :)

Solution 184498

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4 Comments

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Tom Holz on 2 Jan 2013

Solution 184561 is a "smaller" implementation of this approach.

Óscar on 3 Jan 2013

Very well done! That was the solution I was expecting.

Tom Holz on 3 Jan 2013

Can you examine the test function's mtree to check for dangerous functions, or save function handles to builtins used by the test suite before calling the user code? Aside from making file i/o impossible (e.g. by fixing the sandbox filesystem permissions before calling user code), I don't see how to prevent these kinds of cheats.

Óscar on 3 Jan 2013

Thank you for your hints! I'll see what to add to "Now! (Anticheating version 2)", I would not like to block file i/o.

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Problem 907. Now! (Anticheating version 1)

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Problem 907. Now! (Anticheating version 1)

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Last 200 Solutions

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