Timeline for Optimal covering of 2D matrix elements given spatial constraints
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 29, 2017 at 20:40 | vote | accept | tomocafe | ||
| Jul 29, 2017 at 20:40 | comment | added | tomocafe | Ah, I understand now. Thank you for the clarification! | |
| Jul 29, 2017 at 18:18 | comment | added | D.W.♦ | @EvanW, I don't think it contradicts the first three inequalities (you can try it!). It ensures that a cell is only covered if it is marked, or the cell above/below it is marked. | |
| Jul 29, 2017 at 16:48 | comment | added | tomocafe | Thanks -- the part I was stuck on was how to set up those inequalities for relating $x_{i,j}$ and $y_{i,j}$. The first three make sense to me since they imply an element is covered if either itself, or one of its two vertical neighbors is marked. But I'm not sure what that last inequality is doing: $y_{i,j} \le x_{i-1,j} + x_{i,j} + x_{i+1,j}$. Doesn't that contradict the first three inequalities? | |
| Jul 29, 2017 at 11:27 | history | answered | D.W.♦ | CC BY-SA 3.0 |