[数据结构与算法]力扣-面试题 16.04题 井字游戏（C++）- 纯思路

题目链接：https://leetcode-cn.com/problems/tic-tac-toe-lcci/
题目如下：

class Solution {
public:
    string tictactoe(vector<string>& board) {
        const int n=board.size();

        int ax=0,ao=0;//左斜
        int bx=0,bo=0;//右斜
        bool isempty=true;
        for(int i=0;i<n;i++){
            if(board[i][i]=='X') ax++;
            else if(board[i][i]=='O') ao++;
            else isempty=false;

            if(board[i][n-i-1]=='X') bx++;
            else if(board[i][n-i-1]=='O') bo++;
            else isempty=false;
        }
        if(ax==n||bx==n) return "X";
        else if(ao==n||bo==n) return "O";

        ax=0,ao=0;//横
        bx=0,bo=0;//竖
        for(int i=0;i<n;i++){
            for(int j=0;j<n;j++){
                if(board[i][j]=='X') ax++;
                else if(board[i][j]=='O') ao++;

                if(board[j][i]=='X') bx++;
                else if(board[j][i]=='O') bo++;

                if(board[i][j]==' ') isempty=false;
            }
            if(ax==n||bx==n) return "X";
            else if(ao==n||bo==n) return "O";
            ax=0,ao=0;//横
            bx=0,bo=0;//竖
        }

        if(isempty==false) return "Pending";
        else return "Draw"; 

    }
};