What game are you talking about? Is this a question about Nullpomino? If so, I don't believe Nullpomino currently has AI suitable for Puyo Puyo.
nmn had written a pretty decent AI for the Puyo modes in NM, but the problem was that it took an extremely long time to think. I suppose the only way to make it good was to introduce large game trees, which leads to combinatorial explosion
Has someone disassembled Kirby's Avalanche for Super NES yet to see how it thinks with a 3.6 MHz 65C816 microprocessor?
I do know off the top of my head that Puyo Puyo has multiple AIs, and which one it uses depends on the character the AI is playing as. One of them builds from the sides towards the middle, and another one (specific to Nohoho) builds from right to left. [Edit: Oh yeah, there's another one specific to Skeleton-T, which never rotates, thus it only has to consider 6 possible placements.] They also seem to have aggressive and defensive modes (some with more than one degree of defensiveness) based on the height of the stack. I'm not completely sure what the trigger(s) are, but Nohoho seems to get much more defensive suddenly when column 3 is at least half-full and column 4 is completely filled. In aggressive mode, most AIs only seem to consider a limited number of possible placements (the side-builder seems to only consider placements with at least one of the two Puyo in column 1 or 6, and Nohoho will only consider placements with at least one Puyo in the column immediately to the left of the leftmost completely filled column out of 3 through 6, or with at least one Puyo in column 6 if no column is completely filled). I've actually got a pretty good idea as to how Nohoho's AI works (though I'm a little fuzzier on its defensive mode); I oughta try to implement it in NullpoMino sometime. [Edit: I just spent about two hours to whip up a basic AI that's vaguely Nohoho-like, and it's committed into the NullpoMino repository now. It's still pretty buggy, but it at least works.]
