Xs and Os Referee
Tic-Tac-Toe, sometimes also known as Xs and Os, is a game for two players (X and O) who take turns marking the spaces in a 3×3 grid. The player who succeeds in placing three respective marks in a horizontal, vertical, or diagonal rows (NW-SE and NE-SW) wins the game.
But we will not be playing this game. You will be the referee for this games results. You are given a result of a game and you must determine if the game ends in a win or a draw as well as who will be the winner. Make sure to return "X" if the X-player wins and "O" if the O-player wins. If the game is a draw, return "D".
A game's result is presented as a list of strings, where "X" and "O" are players' marks and "." is the empty cell.
Input: A game result as a list of strings (unicode).
Output: "X", "O" or "D" as a string.
Example:
checkio([
"X.O",
"XX.",
"XOO"]) == "X"
checkio([
"OO.",
"XOX",
"XOX"]) == "O"
checkio([
"OOX",
"XXO",
"OXX"]) == "D"
How it is used: The concepts in this task will help you when iterating data types. They can also be used in game algorithms, allowing you to know how to check results.
Precondition:
There is either one winner or a draw.
len(game_result) == 3
all(len(row) == 3 for row in game_result)
