4 ms·
Try just placing 73 1's. You need to be able to place that many, but I can't get more than 65.
by scythe 17y ago
Try just placing 73 1's. You need to be able to place that many, but I can't get more than 65.
- RiderOfGiraffes 17y agoI've got 67 just using random placements with heuristics, programmed in Python. Apparently they've got 73 (which is 289/4 rounded up), and that's why they think this might be possible.
- abentspoon 17y agoI've placed 74 using an IP solver 1 1 . . . . . 1 1 . . . . . 1 . . . 1 1 1 1 . . . . . . . . . . . . 1 . 1 . . 1 . . . . . 1 . . . . 1 1 . . 1 . . 1 . . . 1 . . . . 1 . 1 . . . 1 . . . . 1 . . . 1 . . . . . . 1 . 1 . 1 . . . . . 1 . . . . 1 . . . 1 1 . . 1 . . . . . . . . . 1 . . . 1 1 . . . . 1 . . . . . . . . 1 1 . . 1 . . . 1 . . 1 . . . 1 . . . . . 1 1 1 . . . . . . . . . . 1 . . 1 . . 1 1 . . . . . . . . . . . 1 . 1 . . 1 . 1 . . . . . . 1 . . . . . 1 . 1 1 . 1 . . . 1 . . . . . . . . 1 . 1 1 . . 1 . . 1 . . . . . . . . . . 1 1 1 . . . . . 1 . 1 . . . . . . . 1 . 1 . . . . . . . 1 . 1 . . . . . 1 1 The solver chokes on anything larger than a 6x6 grid, but I've had good luck adding one row at a time to a smaller solution. http://pastebin.com/m4c4696af http://pastebin.com/m4c4696af edit: He mentions that he already found a size 74 set in one of the linked pdfs. http://www.cs.umd.edu/~gasarch/BLOGPAPERS/17x17.pdf http://www.cs.umd.edu/~gasarch/BLOGPAPERS/17x17.pdf