<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:               
        m = len(grid)
        n = len(grid[0])
        mapped_grid = [[0] * 3 * n for _ in range(3*m)]
        
        for i in range(m):
            for j in range(n):
                if grid[i][j] == "/":
                    mapped_grid[i * 3][j * 3 + 2] = 1
                    mapped_grid[i * 3 + 1][j * 3 + 1] = 1
                    mapped_grid[i * 3 + 2][j * 3] = 1
                elif grid[i][j] == "\\":
                    mapped_grid[i * 3][j * 3] = 1
                    mapped_grid[i * 3 + 1][j * 3 + 1] = 1
                    mapped_grid[i * 3 + 2][j * 3 + 2] = 1
        
        visited = set()
        regions = 0
        
        m = len(mapped_grid)
        n = len(mapped_grid[0])
        
        def dfs(mapped_grid, i, j):
            if i not in range(m) or j not in range(n) or mapped_grid[i][j] == 1 or (i, j) in visited:
                return
            
            visited.add((i, j))
            dirs = [[0, 1], [1, 0], [0, -1], [-1, 0]]
            
            for dr, dc in dirs:
                dfs(mapped_grid, i + dr, j + dc)
        
        for i in range(m):
            for j in range(n):
                if mapped_grid[i][j] == 0 and (i, j) not in visited:
                    dfs(mapped_grid, i, j)
                    regions += 1
        
        return regions
        
        
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