<p>In an&nbsp;<code>n*n</code>&nbsp;grid, there is a snake that spans 2 cells and starts moving from the top left corner at <code>(0, 0)</code> and <code>(0, 1)</code>. The grid has empty cells represented by zeros and blocked cells represented by ones. The snake wants to reach the lower right corner at&nbsp;<code>(n-1, n-2)</code>&nbsp;and&nbsp;<code>(n-1, n-1)</code>.</p>

<p>In one move the snake can:</p>

<ul>
	<li>Move one cell to the right&nbsp;if there are no blocked cells there. This move keeps the horizontal/vertical position of the snake as it is.</li>
	<li>Move down one cell&nbsp;if there are no blocked cells there. This move keeps the horizontal/vertical position of the snake as it is.</li>
	<li>Rotate clockwise if it&#39;s in a horizontal position and the two cells under it are both empty. In that case the snake moves from&nbsp;<code>(r, c)</code>&nbsp;and&nbsp;<code>(r, c+1)</code>&nbsp;to&nbsp;<code>(r, c)</code>&nbsp;and&nbsp;<code>(r+1, c)</code>.<br />
	<img alt="" src="https://assets.leetcode.com/uploads/2019/09/24/image-2.png" style="width: 300px; height: 134px;" /></li>
	<li>Rotate counterclockwise&nbsp;if it&#39;s in a vertical position and the two cells to its right are both empty. In that case the snake moves from&nbsp;<code>(r, c)</code>&nbsp;and&nbsp;<code>(r+1, c)</code>&nbsp;to&nbsp;<code>(r, c)</code>&nbsp;and&nbsp;<code>(r, c+1)</code>.<br />
	<img alt="" src="https://assets.leetcode.com/uploads/2019/09/24/image-1.png" style="width: 300px; height: 121px;" /></li>
</ul>

<p>Return the minimum number of moves to reach the target.</p>

<p>If there is no way to reach the target, return&nbsp;<code>-1</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<p><strong><img alt="" src="https://assets.leetcode.com/uploads/2019/09/24/image.png" style="width: 400px; height: 439px;" /></strong></p>

<pre>
<strong>Input:</strong> grid = [[0,0,0,0,0,1],
               [1,1,0,0,1,0],
&nbsp;              [0,0,0,0,1,1],
&nbsp;              [0,0,1,0,1,0],
&nbsp;              [0,1,1,0,0,0],
&nbsp;              [0,1,1,0,0,0]]
<strong>Output:</strong> 11
<strong>Explanation:
</strong>One possible solution is [right, right, rotate clockwise, right, down, down, down, down, rotate counterclockwise, right, down].
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> grid = [[0,0,1,1,1,1],
&nbsp;              [0,0,0,0,1,1],
&nbsp;              [1,1,0,0,0,1],
&nbsp;              [1,1,1,0,0,1],
&nbsp;              [1,1,1,0,0,1],
&nbsp;              [1,1,1,0,0,0]]
<strong>Output:</strong> 9
</pre>

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

<ul>
	<li><code>2 &lt;= n &lt;= 100</code></li>
	<li><code>0 &lt;= grid[i][j] &lt;= 1</code></li>
	<li>It is guaranteed that the snake starts at empty cells.</li>
</ul>

from collections import deque

class Solution:
    def minimumMoves(self, grid):
        n = len(grid)
        # Use deque for BFS
        queue = deque([((0, 0, 0, 1, 0), 0)])  # ((r1, c1, r2, c2, orientation), moves)
        visited = set([(0, 0, 0, 1, 0)])

        while queue:
            (r1, c1, r2, c2, orientation), moves = queue.popleft()

            if (r1, c1, r2, c2) == (n-1, n-2, n-1, n-1) and orientation == 0:
                return moves

            # Move right
            if orientation == 0 and c2 + 1 < n and grid[r1][c2+1] == 0:
                if (r1, c1+1, r2, c2+1, 0) not in visited:
                    visited.add((r1, c1+1, r2, c2+1, 0))
                    queue.append(((r1, c1+1, r2, c2+1, 0), moves + 1))
            
            # Move down
            if orientation == 1 and r2 + 1 < n and grid[r2+1][c1] == 0:
                if (r1+1, c1, r2+1, c2, 1) not in visited:
                    visited.add((r1+1, c1, r2+1, c2, 1))
                    queue.append(((r1+1, c1, r2+1, c2, 1), moves + 1))
            
            # Right move if vertical or horizontal (both tails have legal cells)
            if orientation == 1:
                if c2 + 1 < n and grid[r1][c2+1] == 0 and grid[r2][c2+1] == 0:
                    if (r1, c1+1, r2, c2+1, 1) not in visited:
                        visited.add((r1, c1+1, r2, c2+1, 1))
                        queue.append(((r1, c1+1, r2, c2+1, 1), moves + 1))

            if orientation == 0:
                if r2 + 1 < n and grid[r2+1][c1] == 0 and grid[r2+1][c2] == 0:
                    if (r1+1, c1, r2+1, c2, 0) not in visited:
                        visited.add((r1+1, c1, r2+1, c2, 0))
                        queue.append(((r1+1, c1, r2+1, c2, 0), moves + 1))
            
            # Clockwise rotation
            if orientation == 0 and r1+1 < n and grid[r1+1][c1] == 0 and grid[r2+1][c2] == 0:
                if (r1, c1, r1+1, c1, 1) not in visited:
                    visited.add((r1, c1, r1+1, c1, 1))
                    queue.append(((r1, c1, r1+1, c1, 1), moves + 1))

            # Counterclockwise rotation
            if orientation == 1 and c1+1 < n and grid[r1][c1+1] == 0 and grid[r2][c2+1] == 0:
                if (r1, c1, r1, c1+1, 0) not in visited:
                    visited.add((r1, c1, r1, c1+1, 0))
                    queue.append(((r1, c1, r1, c1+1, 0), moves + 1))

        return -1
18700