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

<p>The board is a <code>3 x 3</code> array that consists of characters <code>&#39; &#39;</code>, <code>&#39;X&#39;</code>, and <code>&#39;O&#39;</code>. The <code>&#39; &#39;</code> character represents an empty square.</p>

<p>Here are the rules of Tic-Tac-Toe:</p>

<ul>
	<li>Players take turns placing characters into empty squares <code>&#39; &#39;</code>.</li>
	<li>The first player always places <code>&#39;X&#39;</code> characters, while the second player always places <code>&#39;O&#39;</code> characters.</li>
	<li><code>&#39;X&#39;</code> and <code>&#39;O&#39;</code> characters are always placed into empty squares, never filled ones.</li>
	<li>The game ends when there are three of the same (non-empty) character filling any row, column, or diagonal.</li>
	<li>The game also ends if all squares are non-empty.</li>
	<li>No more moves can be played if the game is over.</li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/05/15/tictactoe1-grid.jpg" style="width: 253px; height: 253px;" />
<pre>
<strong>Input:</strong> board = [&quot;O  &quot;,&quot;   &quot;,&quot;   &quot;]
<strong>Output:</strong> false
<strong>Explanation:</strong> The first player always plays &quot;X&quot;.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/05/15/tictactoe2-grid.jpg" style="width: 253px; height: 253px;" />
<pre>
<strong>Input:</strong> board = [&quot;XOX&quot;,&quot; X &quot;,&quot;   &quot;]
<strong>Output:</strong> false
<strong>Explanation:</strong> Players take turns making moves.
</pre>

<p><strong class="example">Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/05/15/tictactoe4-grid.jpg" style="width: 253px; height: 253px;" />
<pre>
<strong>Input:</strong> board = [&quot;XOX&quot;,&quot;O O&quot;,&quot;XOX&quot;]
<strong>Output:</strong> true
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>board.length == 3</code></li>
	<li><code>board[i].length == 3</code></li>
	<li><code>board[i][j]</code> is either <code>&#39;X&#39;</code>, <code>&#39;O&#39;</code>, or <code>&#39; &#39;</code>.</li>
</ul>

class Solution:
    def validTicTacToe(self, board: List[str]) -> bool:
        for i in board:
            print(i)
        n=3
        row0,row1 = defaultdict(int),defaultdict(int)
        col0,col1 = defaultdict(int),defaultdict(int)
        dia0,dia1 = 0,0
        antidia0,antidia1 = 0,0
        flag0,flag1=False,False
        for i in range(n):
            for j in range(n):
                if board[i][j]=='X':
                    row0[i]+=1
                    col0[j]+=1
                    if i==j:dia0+=1
                    if i+j==n-1:antidia0+=1
                    if (row0[i]==n or col0[j]==n or dia0==n or antidia0==n):flag0=True
                elif board[i][j]=='O':
                    row1[i]+=1
                    col1[j]+=1
                    if i==j:dia1+=1
                    if i+j==n-1:antidia1+=1
                    if row1[i]==n or col1[j]==n or dia1==n or antidia1==n:flag1=True
        # X win, O count<X count
        # O win, X count=O count
        # X count=O count or O count+1
        if not (sum(row0.values())==sum(row1.values()) or sum(row0.values())==sum(row1.values())+1) or (flag0 and sum(row0.values())<=sum(row1.values())) or (flag1 and sum(row0.values())>sum(row1.values())): return False
        return True

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