Tic-Tac-Toe

Game logic

Game Logic code

def init_game(game_settings):
    state = {
        "player_turn_idx": 0,
        "board": [-1, -1, -1, -1, -1, -1, -1, -1, -1]
        }
    return state

def place_piece(state, index):
    if index < 0 or index > 8:
        raise InvalidActionError("Index out of bound")
    if state["board"][index] != -1:
        raise InvalidActionError("Someone already placed a piece here")
    state["board"][index] = state["player_turn_idx"]
    state["player_turn_idx"] = (state["player_turn_idx"] + 1) % 2

    return state

def get_game_result(state):
    if __has_line(state, 0):
        return {
            "game_result": "Winner",
            "winner_idx": 0
        }
    if __has_line(state, 1):
        return {
            "game_result": "Winner",
            "winner_idx": 1
        }
    for value in state["board"]:
        if value == -1:
            return {
                "game_result": "NoWinnerYet"
            }
    return {
        "game_result": "Draw"
    }

def __has_line(state, value):
    for i in range(0, 3):
        if state["board"][i*3] == value and state["board"][i*3 + 1] == value and state["board"][i*3 + 2] == value:
            return True
        if state["board"][i] == value and state["board"][i + 3] == value and state["board"][i + 6] == value:
            return True
    if state["board"][0] == value and state["board"][4] == value and state["board"][8] == value:
        return True
    if state["board"][2] == value and state["board"][4] == value and state["board"][6] == value:
        return True
    return False

Game state schema

message State {
  // Required field to indicate the player who should be making the next move
  // Values = 0 or 1
  int32 player_turn_idx = 1;

  /*
  Array of size 9 initialized to -1, representing an empty 3 by 3 board.
  The values of board can be -1, 0, or 1. 
  Placing a piece in index x will set the value of board[x] to the player's index.
  Array is row major order: index 0 is top left, index 2 is top right, index 6 is 
  bottom left, and index 8 is bottom right.
  */
  repeated int32 board = 2;
}

Action schema

place_piece(int index)

Start building now