TODO-solver.txt

interference graph
make sure there are no leaves,
starting from winning, make a graph of what interferes with paths
make sure everything is in a loop




using trove for long sets and maps



switch exclusively to packed-car notation




investigate using bitset
bitset probably isn't going to work
can't figure out how to really compress the boards, always taking up about 64 bits for 8 cars






memoize each row!
probably won't work either




need to prune dead ends
look at simply 2 2car 1 3car or something, and see how the easier branches are different than the ultimately hardest branch
visualize



determine 1 move away from clear path?




partition based on invariants







right now, 14 cars seems to suffice to 6x6 board
if ever generalized and need more bits for cars:
only use ABCD in configs to encode cars
rely on 4 color theorem
scan through to find second occurrence of A car, then that is car#5

this gets around the current limitation of only 14 cars

so will never need more than 4 bits for each coor of board, so 4x6x6 = 18 bytes maximum for any number of cars




can use 1 byte per car, so up to 18 cars, use packed-car notation










no garbage collection
audit all for loops





create a level database:
rows by cols, j?, k?, #2cars, #3cars



level generator

rows
cols
exit
# of 2cars
# of 3cars
placement of cars
j joints?
k joints?
joints cannot be next to each other (vertices touch)
matching joints must be on neighbring sides
joints cannot be on side of exit
loops? loops are fine