GetChildren takes too much time + outputs too many children

[YoshuaNava]

I modified the GetChildren method of GameNode, so that the GameNodes are self-contained, and we don't need to go back and forth between state and nodes. Hence, our successor function is part of the GameNode definition. The new method is:

    def getChildren(self):
        children = []
        # Translations relative to the middle of the board
        for translation in range(-5, 6, 1):
            for rotation in range(0, 4, 1):  # Number of rotations
                # Simulate the game by dong a few rotations and translations: get the new state (for each performed move)
                new_state = GameState.TetrisGame(self.state.grid, self.state.curr_piece, self.state.next_piece, rotation, translation)
                action = (rotation, translation)
                child = GameNode(new_state, self, action)
                children.append(child)
                # Calculate the hash value
                # hash_val = abs(hash(new_state_string))
                # Check for hash collision
                # if (self.hashtable[hash_val % 1000000] == 0):
                #     self.hashtable[hash_val % 1000000] = 1
                #     child = GameNode(new_state.getGrid(), piece, next_piece, new_state.getActions())
                #     self.children.append(child)
        return children

However, I'm getting about 44 children out of each state. I think we should only take into account some of them. But which ones?

Furthermore, this function takes quite some CPU time. I think it could be because we run deepcopy while creating new GameState objects. Could this be the case?

[viktortuul]

Hashing now works properly, no more duplicate nodes.

Considering the CPU time, we could start with managing the ranges in;

for translation in range(-5, 6, 1):
for rotation in range(0, 4, 1):

such that not unnecessary game simulations are done. For example, if a square block is falling there is no point in rotating it. If this does not make it, we should indeed look into how we manage the GameState objects.