<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>

class Solution:
    def minimumMoves(self, grid: List[List[int]]) -> int:
        n = len(grid)
        h = []
        for i in grid[0][1:]:
            if i == 0:
                h.append(0)
            else:
                h += [float('INF')] * (n - 1 - len(h))
                break

        v = [float('INF')]
        for i in range(n-1):
            if grid[1][i] == 0:
                v.append(v[-1])
                if grid[0][i+1] == 0 and grid[1][i+1] == 0:
                    v[-1] = min(v[-1], h[i] + 1)
            else:
                v.append(float('INF'))
        v.pop(0)

        grid.append([1] * n)

        for i in range(1,n):
            j = 0
            if grid[i][0] == 1:
                h[0],v[0] = float('INF'), float('INF')
            else:
                if grid[i][1] == 0 and grid[i+1][0] == 0:
                    if grid[i+1][1] == 0:
                        if h[j] < v[j]:
                            v[j] = h[j] + 1
                        elif v[j] < h[j]:
                            h[j] = v[j] + 1
                elif grid[i][1] == 0:
                    v[j] = float('INF')
                elif grid[i+1][j] == 0:
                    h[j] = float('INF')
                else:
                    h[j],v[j] = float('INF'),float('INF')
            
            for j in range(1,n - 1):
                if grid[i][j] == 1:
                    h[j],v[j] = float('INF'), float('INF')
                    continue
                if grid[i][j + 1] == 0 and grid[i+1][j] == 0:
                    h[j] = min(h[j],h[j-1])
                    v[j] = min(v[j],v[j-1])
                    if grid[i+1][j+1] == 0:
                        if h[j] < v[j]:
                            v[j] = h[j] + 1
                        elif v[j] < h[j]:
                            h[j] = v[j] + 1
                elif grid[i][j + 1] == 0:
                    h[j] = min(h[j],h[j-1])
                    v[j] = float('INF')
                elif grid[i+1][j] == 0:
                    v[j] = min(v[j],v[j-1])
                    h[j] = float('INF')
                else:
                    h[j],v[j] = float('INF'),float('INF')
                
        res = h[-1] + n * 2 - 3
        return res if res < float('INF') else -1
17100