Databases
StackOverflow2013
Postsdbo
POCheck that list members are in groups of 4, in a row
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POCheck that list members are in groups of 4, in a row
    primarykey
    data
    text
    <p>I have a list of objects that have coordinates. The object is something like this:</p> <pre><code>private class Seats { public string Code { get; set; } public long PosX { get; set; } public long PosY { get; set; } } </code></pre> <p>For all Seats inside the list, I need to know that they are in group of 4, in a horizontal row. For example, the list below is fine:</p> <pre><code>List&lt;Seats&gt; good = new List&lt;Seats&gt; { new Seats {Code = "A1", PosX = 0, PosY = 0}, new Seats {Code = "A2", PosX = 1, PosY = 0}, new Seats {Code = "A3", PosX = 2, PosY = 0}, new Seats {Code = "A4", PosX = 3, PosY = 0} }; </code></pre> <p>The list below is also OK (two rows):</p> <pre><code>List&lt;Seats&gt; good = new List&lt;Seats&gt; { new Seats {Code = "A1", PosX = 0, PosY = 0}, new Seats {Code = "A2", PosX = 1, PosY = 0}, new Seats {Code = "A3", PosX = 2, PosY = 0}, new Seats {Code = "A4", PosX = 3, PosY = 0}, new Seats {Code = "B1", PosX = 0, PosY = 1}, new Seats {Code = "B2", PosX = 1, PosY = 1}, new Seats {Code = "B3", PosX = 2, PosY = 1}, new Seats {Code = "B4", PosX = 3, PosY = 1} }; </code></pre> <p>The list below is also OK (same row, two groups, gap at (4,0)):</p> <pre><code>List&lt;Seats&gt; good = new List&lt;Seats&gt; { new Seats {Code = "A1", PosX = 0, PosY = 0}, new Seats {Code = "A2", PosX = 1, PosY = 0}, new Seats {Code = "A3", PosX = 2, PosY = 0}, new Seats {Code = "A4", PosX = 3, PosY = 0}, new Seats {Code = "A6", PosX = 5, PosY = 0}, new Seats {Code = "A7", PosX = 6, PosY = 0}, new Seats {Code = "A8", PosX = 7, PosY = 0}, new Seats {Code = "A9", PosX = 8, PosY = 0} }; </code></pre> <p>But the list below is not OK because there is a gap at (3,0):</p> <pre><code>List&lt;Seats&gt; bad1 = new List&lt;Seats&gt; { new Seats {Code = "A1", PosX = 0, PosY = 0}, new Seats {Code = "A2", PosX = 1, PosY = 0}, new Seats {Code = "A3", PosX = 2, PosY = 0}, new Seats {Code = "A5", PosX = 4, PosY = 0} }; </code></pre> <p>The list below is also not OK because there are five of them:</p> <pre><code>List&lt;Seats&gt; bad2 = new List&lt;Seats&gt; { new Seats {Code = "A1", PosX = 0, PosY = 0}, new Seats {Code = "A2", PosX = 1, PosY = 0}, new Seats {Code = "A3", PosX = 2, PosY = 0}, new Seats {Code = "A4", PosX = 3, PosY = 0}, new Seats {Code = "A5", PosX = 4, PosY = 0} }; </code></pre> <p>The list below is also not OK because the four Seats need to be in a horizontal row:</p> <pre><code>List&lt;Seats&gt; bad3 = new List&lt;Seats&gt; { new Seats {Code = "A1", PosX = 0, PosY = 0}, new Seats {Code = "A2", PosX = 1, PosY = 0}, new Seats {Code = "B1", PosX = 0, PosY = 1}, new Seats {Code = "B2", PosX = 1, PosY = 1} }; </code></pre> <p>For checking multiplication of 4 (it can be 8, 12, ...) I can just do:</p> <pre><code>list.Count % 4 == 0 </code></pre> <p>But I need help in how to check 'in a row'.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USEndy Tjahjono
    1. USEndy Tjahjono
    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
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POCheck that list members are in groups of 4, in a row
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POCheck that list members are in groups of 4, in a row
      1. This table or related slice is empty.
      1. VTUpMod
    1. COFor records to be "in one row" they should have the same PosY value.
      singulars
      1. POCheck that list members are in groups of 4, in a row
      1. USCandide
    2. CO@Ingenu I added another good sample with 2 rows.
      singulars
      1. POCheck that list members are in groups of 4, in a row
      1. USEndy Tjahjono
    3. COThis seems to me like a good place for someone to suggest a LINQ to objects solution; "if there is more than one member where there isn't another member with an X coordinate one lower" would be a way to express it. Also if you know the value of hte lowest X the sum of all X coords should be 4x+(1+2+3), if there are 4 and they are different and total 4x+6... I'm curious tho if lots of people would approach this as a set-based, LINQ-is-appropriate problem.
      singulars
      1. POCheck that list members are in groups of 4, in a row
      1. USLevin Magruder
 

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