#         Choose the level of you game.
#         Enter:
#          1 - Easy
#          2 - Normal
#          3 - Hard
#         3
#          0 | 1 | 2 |
#         ===+===+===
#          3 | 4 | 5 |
#         ===+===+===
#          6 | 7 | 8 |
#         Enter [0-8]:
#         0
#          O | 1 | 2 |
#         ===+===+===
#          3 | 4 | X |
#         ===+===+===
#          6 | 7 | 8 |
#         1
#          O | O | X |
#         ===+===+===
#          3 | 4 | X |
#         ===+===+===
#          6 | 7 | 8 |
#         8
#          O | O | X |
#         ===+===+===
#          3 | X | X |
#         ===+===+===
#          6 | 7 | O |
#         3
#          O | O | X |
#         ===+===+===
#          O | X | X |
#         ===+===+===
#          X | 7 | O |
#
#    next_player será o player da vez. Cpu ou Cpuplayer1 ou Cpuplayer2

board = (0..8).to_a

oponent = "X"
oponent = "O" if next_player == "X"

return 0 if board[0] == 0 && board[1] == next_player && board[2] == next_player
return 0 if board[0] == 0 && board[4] == next_player && board[8] == next_player
return 0 if board[0] == 0 && board[3] == next_player && board[6] == next_player

return 1 if board[1] == 1 && board[0] == next_player && board[2] == next_player
return 1 if board[1] == 1 && board[4] == next_player && board[7] == next_player

return 2 if board[2] == 2 && board[0] == next_player && board[1] == next_player
return 2 if board[2] == 2 && board[4] == next_player && board[6] == next_player
return 2 if board[2] == 2 && board[5] == next_player && board[8] == next_player

return 3 if board[3] == 3 && board[0] == next_player && board[6] == next_player
return 3 if board[3] == 3 && board[4] == next_player && board[5] == next_player

return 4 if board[4] == 4 && board[0] == next_player && board[8] == next_player
return 4 if board[4] == 4 && board[1] == next_player && board[7] == next_player
return 4 if board[4] == 4 && board[2] == next_player && board[6] == next_player
return 4 if board[4] == 4 && board[3] == next_player && board[5] == next_player

return 5 if board[5] == 5 && board[2] == next_player && board[8] == next_player
return 5 if board[5] == 5 && board[3] == next_player && board[4] == next_player

return 6 if board[6] == 6 && board[0] == next_player && board[3] == next_player
return 6 if board[6] == 6 && board[2] == next_player && board[4] == next_player
return 6 if board[6] == 6 && board[7] == next_player && board[8] == next_player

return 7 if board[7] == 7 && board[1] == next_player && board[4] == next_player
return 7 if board[7] == 7 && board[6] == next_player && board[8] == next_player

return 8 if board[8] == 8 && board[0] == next_player && board[4] == next_player
return 8 if board[8] == 8 && board[2] == next_player && board[5] == next_player
return 8 if board[8] == 8 && board[6] == next_player && board[7] == next_player

return 0 if board[0] == 0 && board[1] == oponent && board[2] == oponent
return 0 if board[0] == 0 && board[4] == oponent && board[8] == oponent
return 0 if board[0] == 0 && board[3] == oponent && board[6] == oponent

return 1 if board[1] == 1 && board[0] == oponent && board[2] == oponent
return 1 if board[1] == 1 && board[4] == oponent && board[7] == oponent

return 2 if board[2] == 2 && board[0] == oponent && board[1] == oponent
return 2 if board[2] == 2 && board[4] == oponent && board[6] == oponent
return 2 if board[2] == 2 && board[5] == oponent && board[8] == oponent

return 3 if board[3] == 3 && board[0] == oponent && board[6] == oponent
return 3 if board[3] == 3 && board[4] == oponent && board[5] == oponent

return 4 if board[4] == 4 && board[0] == oponent && board[8] == oponent
return 4 if board[4] == 4 && board[1] == oponent && board[7] == oponent
return 4 if board[4] == 4 && board[2] == oponent && board[6] == oponent
return 4 if board[4] == 4 && board[3] == oponent && board[5] == oponent

return 5 if board[5] == 5 && board[2] == oponent && board[8] == oponent
return 5 if board[5] == 5 && board[3] == oponent && board[4] == oponent

return 6 if board[6] == 6 && board[0] == oponent && board[3] == oponent
return 6 if board[6] == 6 && board[2] == oponent && board[4] == oponent
return 6 if board[6] == 6 && board[7] == oponent && board[8] == oponent

return 7 if board[7] == 7 && board[1] == oponent && board[4] == oponent
return 7 if board[7] == 7 && board[6] == oponent && board[8] == oponent

return 8 if board[8] == 8 && board[0] == oponent && board[4] == oponent
return 8 if board[8] == 8 && board[2] == oponent && board[5] == oponent
return 8 if board[8] == 8 && board[6] == oponent && board[7] == oponent