TODO

= minei todo list

(O) 0. filter out impossible tiles
       (tkcn) (not only for reducing computing, if we don't filter it,
               it's very hard to calculate the real combos)

(X) 1. short-circuit when best match (100%) found. (reduce computing)

(O) 2. use better algorithm to split ClueSet instead of nearby
       (stimim) (more accurate comparing to calculate nearby 2)

(O) 3. use combinations of overlapped clues to calculate combos
       (real probability)

(X) 4. do we consider the remaining mines? (tkcn) (more real probability)

(X) 5. pick the worst when there's no target > 50% (defense)

(X) 6. do we consider the probability for opponent if minei failed to hit
       the mine? thus, we'll need to calculate the score for the input,
       so it will truly be a minimax algorithm. (stimim) (scoring)