Re:Donald Knuth's 2024 Christmas Lecture: Strong and Weak Co...
by mafuy on Friday February 07, 2025 @05:24AM
(#42971155)
From a rough estimation, it should not run out of memory with these constraints. The matrix should be about 1m rows * 16 cells/row * (4 pointers/cell + overhead?) * 8 bytes/pointer = approx 1 GB. That's quite little.
The dynamic memory is negligible with 104 cols, avg search depth should only be around 104/16.
I wonder if the updated algorithm is using less memory.
My guess is that this large problem has about a hundred million solutions. So, even if it finds a hundred solutions per second, it still would require about ten days to finish.
The problem, I am working on, is the number of solutions to the 'Fancy Tetris Houten Puzzel' where all pieces of the same color touch are connected by at least one side touching another side of a piece with the same color.
I have been thinking about other algorithms for solving this Exact Cover problem that are less memory sensitive.