CC1-5 Knapsack




To pack a knapsack of a fixed size using given objects (of fixed sizes) in the most efficient way is the aim of all knapsack problems. Multiple variations of this problem are known but we are using only objects that can be completely characterized by their size.

We present further information in this [PDF]. But there's one hint (it's also in the PDF) for the curious among you: The game uses pointers and arcs to visualize the Modulo-Arithmetic. Usually, one starts counting at 0 after a pointer has completed a 360° rotation (e.g. on clocks). A full rotation is the equivalent of surpassing the modulus M. By resetting the count to 0 one obtaines the integer remainder mod M.




How-To
  • The CC can be started here. Its aim is, to en- and decrypt a PIN successfully. In the third step, you'll have to break the crypto system.
     
  • Non-registered users get a new challenge each time they start the challenge, while registered get the same challenge until it is solved or deleted (see the menu on top of the game).
     
  • Registered users can use the save- button in the challenge to save the current state and continue playing later.
     
  • The programmers interface returns on http://www.mystery-twister.com/cc1-5/interface.php the game data in a parser friendly format. Using the call http://www.mystery-twister.com/cc1-5/interface.php?check=0000 one can check his results. (The zeros have to be replaced by the result.) The values (knapsack and PIN) are a little bit bigger than those used for the Flash game. Else, Brute Force attacks would be too easy.




FAQ for this CC

Q:  Are more precise instructions available?
A: There is a "More Info..." button in the game. If you click on it, you'll get instructions on the usage of the device. The cryptographic system is described in the PDF above. If you have further questions, you can post them to the forum.

Q:  I can't solve the game, can I try another key-PIN-combination?
A: As a registered user, you can delete your current challenge in the menu of the game. Non-registered users get new challenges whenever they start the game.

Q:  How can I save my results using the programmers interface?
A: The results will be saved automatically on each interface call.

Q:  How is the ranking score determined?
A: The failcounter rates the results of programmers. A clever cryptanalytic attack, always producing the correct results, will be preferred over more or less qualified guessing (brute force) that way.




CC1-5: Links & Tools
» Start the game
» Programmers interface
» Forum
» Ranking



CC1-5: Stats
Currently 127 players are in this CC. 24 already have solved it.




Top of page Last change 2006.11.10 10:40
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