74th LeetCode Weekly Contest Valid Tic-Tac-Toe State

A Tic-Tac-Toe board is given 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, and 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 3 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 = ["XXX", "   ", "OOO"]
Output: false

Example 4:
Input: board = ["XOX", "O O", "XOX"]
Output: true

Note:

• board is a length-3 array of strings, where each string board[i] has length 3.
• Each board[i][j] is a character in the set {" ", "X", "O"}.

判断井字棋是不是合法状态，想怎么判断就怎么判断吧

 class Solution {
 public:
     char Board[][];
     bool check(int x,int y,int dx,int dy,char c){
         for(int i=;i<;i++){
             if(Board[x][y]!=c){
                 return ;
             }
             x+=dx;
             y+=dy;
         }
         return ;
     }
     bool win(char a){
         for(int i=;i<;i++){
             if(check(,i,,,a)){
                 return ;
             }
             if(check(i,,,,a)){
                 return ;
             }
         }
         if(check(,,,,a)){
             return ;
         }
         if(check(,,,-,a)){
             return ;
         }
         return ;
     }
     bool validTicTacToe(vector<string>& board) {

         int X=;
         int O=;
         int len=board.size();
         for(int i=;i<len;i++){

             for(int j=;j<;j++){

                     Board[i][j]=board[i][j];

                 if(Board[i][j]=='X'){
                     X++;
                 }
                 if(Board[i][j]=='O'){
                     O++;
                 }
             }
           //  Str="";
         }
         if(X!=O&&O+!=X){
             return false;
         }
         int x=win('X');
         int o=win('O');
         if(o+x>=){
             return false;
         }
         // for(int i=0;i<3;i++){
         //     for(int j=0;j<3;j++){
         //         cout<<Board[i][j];
         //     }
         //     cout<<endl;
         // }
         if(x){
             return X==(O+);
         }
         if(o){
             //cout<<o<<endl;
             return X==O;
         }
         return true;
     }
 };