<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:
        pixels = []
        for line in grid:
            row1 = []
            row2 = []
            row3 = []
            for char in line:
                if char == " ":
                    row1.extend([0,0,0])
                    row2.extend([0,0,0])
                    row3.extend([0,0,0])
                elif char == "/":
                    row1.extend([0,0,1])
                    row2.extend([0,1,0])
                    row3.extend([1,0,0])
                elif char == "\\":
                    row1.extend([1,0,0])
                    row2.extend([0,1,0])
                    row3.extend([0,0,1])
            pixels.append(row1)
            pixels.append(row2)
            pixels.append(row3)
        
        regions = 0
        visited = set()
        for r in range(len(pixels)):
            for c in range(len(pixels[0])):
                if (r,c) not in visited and pixels[r][c] == 0:
                    dfs(r, c, pixels, visited)
                    regions += 1
        return regions

def dfs(r, c, grid, visited):
    for x, y in [(r+1,c),(r-1,c),(r,c+1),(r,c-1)]:
        if 0 <= x < len(grid) and 0 <= y < len(grid[0]) and (x, y) not in visited and grid[r][c] != 1:
            visited.add((x,y))
            dfs(x, y, grid, visited)




""" 
["//","/ "]
0 1 0 1
1 0 1 0
0 1 0 0 
1 0 0 0 


time: O(n*m) n number of lines, m is len(line)
space: O(n*m)


each space / or \ is a 
00 01 10
00 10 01

grid = [" /","/ "]
0001
0010
0100
1000

grid = [" /","  "]
01
00

grid = ["/\\","\\/"]
0110
1001
1001
0110

convert this grid into pixels
then dfs on the new pixels grid finding how many islands
"""
18320