<p>An <code>n x n</code> grid is composed of <code>1 x 1</code> squares where each <code>1 x 1</code> square consists of a <code>&#39;/&#39;</code>, <code>&#39;\&#39;</code>, or blank space <code>&#39; &#39;</code>. These characters divide the square into contiguous regions.</p>

<p>Given the grid <code>grid</code> represented as a string array, return <em>the number of regions</em>.</p>

<p>Note that backslash characters are escaped, so a <code>&#39;\&#39;</code> is represented as <code>&#39;\\&#39;</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2018/12/15/1.png" style="width: 200px; height: 200px;" />
<pre>
<strong>Input:</strong> grid = [&quot; /&quot;,&quot;/ &quot;]
<strong>Output:</strong> 2
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2018/12/15/2.png" style="width: 200px; height: 198px;" />
<pre>
<strong>Input:</strong> grid = [&quot; /&quot;,&quot;  &quot;]
<strong>Output:</strong> 1
</pre>

<p><strong class="example">Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2018/12/15/4.png" style="width: 200px; height: 200px;" />
<pre>
<strong>Input:</strong> grid = [&quot;/\\&quot;,&quot;\\/&quot;]
<strong>Output:</strong> 5
<strong>Explanation: </strong>Recall that because \ characters are escaped, &quot;\\/&quot; refers to \/, and &quot;/\\&quot; refers to /\.
</pre>

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

<ul>
	<li><code>n == grid.length == grid[i].length</code></li>
	<li><code>1 &lt;= n &lt;= 30</code></li>
	<li><code>grid[i][j]</code> is either <code>&#39;/&#39;</code>, <code>&#39;\&#39;</code>, or <code>&#39; &#39;</code>.</li>
</ul>

class Solution:
    def regionsBySlashes(self, grid: List[str]) -> int:
        upscale = [[0 for _ in range(len(grid[0] * 3))] for _ in range(len(grid) * 3)]
        regions = 0
        for i, row in enumerate(grid):
            for j, c in enumerate(row):
                if c == "/":
                    upscale[i * 3][j * 3 + 2] = 1
                    upscale[i * 3 + 1][j * 3 + 1] = 1
                    upscale[i * 3 + 2][j * 3] = 1
                elif c == "\\":
                    upscale[i * 3][j * 3] = 1
                    upscale[i * 3 + 1][j * 3 + 1] = 1
                    upscale[i * 3 + 2][j * 3 + 2] = 1
        
        def isValid(row, col):
            return row >= 0 and row < len(upscale) and col >= 0 and col < len(upscale[0])
        
        def dfs(row, col):
            if not isValid(row,col):
                return
            elif upscale[row][col] == 1 or upscale[row][col] == -1:
                return
            
            upscale[row][col] = -1

            dfs(row + 1, col)
            dfs(row - 1, col)
            dfs(row, col + 1)
            dfs(row, col - 1)


        for row, arr in enumerate(upscale):
            for col, num in enumerate(arr):
                if num == 0:
                    regions += 1
                    dfs(row, col)
        
        return regions
        
17559