lab_tic_tac_toe/assessment.md

Tic Tac Toe Lab Assessment

Checkpoint 1

Looks good.

Checkpoint 2

What I do not understand is what state is and why we need to use state["board"][index] to access something on the board

I think you asked a similar question in Discord, so maybe you already have an understanding, but state is just a dict storing what's on the board and whose turn it is. State isn't related to syntax--python doesn't care about state at all. Instead, state is a design feature of this program. We intentionally design the TTTGame so that it encodes the rules of the game, but doesn't know anything about the particular game(s) which are actually being played. That's stored within state.

The benefit of organizing a program this way is that we can then reason about multiple future states of the game, for example in the lookahead strategy introduced later in the lab. We can draw an expanding chain of states out into the future, and think about which futures are best. To see t

Checkpoint 3

Actually, the current and future reward (they're added together) is 0. This means that if both players play perfectly, the game will end in a draw every time. You could see this using:

>>> from ttt.game import TTTGame
>>> from strategy.lookahead_strategy import LookaheadStrategy
>>> g = TTTGame()
>>> s = LookaheadStrategy(g)
>>> s.get_current_and_future_reward(g.get_initial_state())