Package g0701_0800.s0794_valid_tic_tac_toe_state

Class Solution

  • public class Solution
extends Object
    794 - Valid Tic-Tac-Toe State.

    Medium

    Given a Tic-Tac-Toe board as a string array board, return true if and only if it is possible to reach this board position during the course of a valid tic-tac-toe game.

    The board is a 3 x 3 array that consists of characters ' ', 'X', and 'O'. The ' ' character represents an empty square.

    Here are the rules of Tic-Tac-Toe:

    • Players take turns placing characters into empty squares ' '.
    • The first player always places 'X' characters, while the second player always places 'O' characters.
    • 'X' and 'O' characters are always placed into empty squares, never filled ones.
    • The game ends when there are three of the same (non-empty) character filling any row, column, or diagonal.
    • The game also ends if all squares are non-empty.
    • No more moves can be played if the game is over.

    Example 1:

    Input: board = ["O “,” “,” "]

    Output: false

    Explanation: The first player always plays “X”.

    Example 2:

    Input: board = [“XOX”," X “,” "]

    Output: false

    Explanation: Players take turns making moves.

    Example 3:

    Input: board = [“XOX”,“O O”,“XOX”]

    Output: true

    Constraints:

    • board.length == 3
    • board[i].length == 3
    • board[i][j] is either 'X', 'O', or ' '.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • validTicTacToe

        public boolean validTicTacToe​(String[] board)