Solving CryptoQuotes with PVM:

Description of the Algorithm


Return to Contents Return to Project Reports

Strengths

The main strength of this program is its ability to solve most quotes which are of sufficient length and good word usage, given an appropriate dictionary. Also, message passing is reduced with the new version, improving time somewhat.


Weaknessess

A big weakness is the amount of message passing which still remains in the algorithm, slowing down the process to the point where the addition of an additional machine does not speed up computation. Another disadvantage is that the cryptoquote solver is not able to solve all cryptoquotes. Perhaps an update could solve this problem by using grammatical hints. In addition, quotes longer than 150 words tend to allocate too much memory, severely limiting the quote length. Finally, there is no load balancing such as that which might take place given the varying nature of different length words.

A solution exists which would address three of these problems: reduction of message passing load balancing, and memory allocation. If the tasks were combined such that all words of a given length were running on one task, then the message passing would be greatly reduced. Reducing the number of tasks would make decisions about load balancing worthwhile with respect to time. Finally, not having to load a dictionary for each task greatly reduces memory use. This tends to indicate that this problem of solving cryptoquotes is a shared memory problem as opposed to the distributed memory structure of PVM.

  • Go back to Using the Programs
  • Go on to Contents


  • Written by:

    Ko-Ming Chang
    Computer Science 397
    Parallel Computing
    Dr. Thomas Whaley
    Washington and Lee University
    Lexington, VA 24450

    Questions? Mail me at kchang@liberty.uc.wlu.edu