7. Battleship is back! Given a 2D board, what is the optimal algorithmic efficiency of a function that checks whether or not the game is over (all boats sunk) under the following conditions? Assume no other knowledge about the game state. Justify your answer.

a. When the board is always the standard battleship board size (10x10):

b. When the board can be of any square shape (e.g. 5x5, 10x10, 100x100):

c. When the board can be any rectangular shape (e.g. 5x5, 5x10, 10x100):