Harmless Rooks puzzle of the week



I was trying to solve “Harmless Rooks”:

I was wondering if someone is getting better scores than required?
Size 5 -> ok
Size 8 -> ok
Size 16 -> ok
Size 30 -> I got 176 on 165
Size 50 -> 504/484
Size 99 -> 2000/1911
Size99 -> 2109/2018
Size99 -> 2166/2076
Size1 -> ok

I`ve triple checked my logic and it looks ok.


Hi, completely independently of your logic, have you triple checked your results (it’s easier to check a solution than to solve a case and should reveal the problem)? For instance, can you post here, or by PM to me if you prefer, your actual solution (rooks positions) for the Size 30 testcase?


damn, your fast :wink:
I have just printed out my result to look for errors and I have found some…
fate of a rookie :stuck_out_tongue:
I was my mistake, which i am hoping to repair :wink: thank you for quick reply anyway :wink:


I can not solve this puzzle
The algorithm I implemented does not fully work.
2 tests with the size of 99 cells failed, the remaining tests pass successfully
Somewhere my logic is broken :confused:


Maybe I can help if you explain your current logic in PM (to avoid spoil).


Same here, I keep missing the result from a few rooks with the 99 tests… Arf


hello all,
My solution works but it is too sloooow. I do not see how to optimize this problem.
I do not want the solution but can you send me some wikipedia links about this type of optimization.