Databases
StackOverflow2013
Postsdbo
POSort a vector of structs
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POSort a vector of structs
    primarykey
    data
    text
    <p>I have a vector of structs and I need help with how to sort them according to one of the values, and if those 2 values are the same, then sort it according to another parameter.</p> <p>This is similar to other questions, but it has more to it.</p> <p>What I am trying to implement is the scan line based polygon fill algorithm.</p> <p>I build the active edge list, but then I need to sort it based on the x value in each struct object. If the x values are the same, then they need to be sorted based on the inverse of the slopes for each struct object.</p> <p>Here is the definition of the struct with the override operator &lt; for normal sorting:</p> <pre><code>struct Bucket { // Fields of a bucket list int ymax, x, dx, dy, sum; // Override the &lt; operator, used for sorting based on the x value bool operator &lt; (const Bucket&amp; var) const { // Check if the x values are the same, if so // sort based on the ivnerse of the slope (dx/dy) /*if(x == var.x) return (dx/dy) &lt; (var.dx/var.dy); else*/ return (x &lt; var.x); } }; </code></pre> <p>I commented out the if then else statement because it does compile, but causes a floating point error and the program crashes. The exact error is: "Floating point exception (core dumped)"</p> <p>I also tried casting each division to (int) but that did not work either.</p> <p>My question: Is there a way to do the sort similar to the way I have it, or should I write my own sort method.</p> <p>If I should make my own sort method, please provide a link or something to a simple method which can help.</p> <p>Thanks</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USRXC
    1. USRXC
    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. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COThese are int values, and as such will perform integer division. Thus casting to ints will not do much good (or anything for that matter). was the original code all floats/doubles? (and if so, can you throw that in the question instead?)
      singulars
      1. POSort a vector of structs
      1. USWhozCraig
    2. COSTL sort + functor!!!
      singulars
      1. POSort a vector of structs
      1. USim so confused
    3. CO@WhozCraig - No, all the values are ints from the struct. This is all code I am writing.
      singulars
      1. POSort a vector of structs
      1. USRXC
 

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