Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>This is easy to solve (a few lines of code) as an integer program. Using a tool like the <a href="http://www.gnu.org/software/glpk/" rel="nofollow noreferrer">GNU Linear Programming Kit</a>, you specify your constraints in a declarative manner and let the solver come up with the best solution. <a href="http://www.ibm.com/developerworks/linux/library/l-glpk1/#N101FE" rel="nofollow noreferrer">Here</a>'s an example of a GLPK program.</p> <p>You could code this using a general-purpose programming language like Python, but this is the type of thing you'll see in the first few chapters of an integer programming textbook. The most efficient algorithms have already been worked out by others.</p> <p>EDIT: to answer Merjit's question:</p> <p>Define:</p> <ol> <li>matrix Y where Y_(ij) = 1 if tape i is played before tape j, and 0 otherwise. </li> <li>vector C, where C_i indicates the time slot when i is played (e.g. 1,2,3,4,5,6,7) </li> <li>Large constant M (look up the term for "big M" in an optimization textbook)</li> </ol> <p>Minimize the sum of the vector C subject to the following constraints:</p> <pre><code>Y_(ij) != Y_(ji) // If i is before j, then j must not be before i C_j &lt; C_k + M*Y_(kj) // the time slot of j is greater than the time slot of k only if Y_(kj) = 1 C_O - C_L = 1 // L must be played immediately before O C_N &gt; C_L // news tape must be played at some time after L |C_G - C_P| = 2 // You will need to manipulate this a bit to make it a linear constraint </code></pre> <p>That should get you most of the way there. You want to write up the above constraints in the MathProg language's syntax (as shown in the links), and make sure I haven't left out any constraints. Then run the GLPK solver on the constraints and see what it comes up with.</p>
    singulars
    1. This table or related slice is empty.
    1. POWhat category of combinatorial problems appear on the logic games section of the LSAT?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USRexE
    1. USRexE
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI think that integer programming is probably the best way to create a set of generalized solutions for this kind of problem, but I'm not sure how to encode a linear sorting game like this as an optimization problem. Where/how would I place the value coefficients?
      singulars
      1. PO
      1. USMerjit
    2. COI edited the answer to get you started.
      singulars
      1. PO
      1. USRexE
    3. COAmazing. I'd vote 2 best answers if I could.
      singulars
      1. PO
      1. USMerjit
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload