<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 {
public:
    int xcord[4] = {-1, 0, 1, 0};
	int ycord[4] = {0, 1, 0, -1};
	void dfs(vector<vector<int>>& grid, vector<vector<int>>& vis, int i, int j) {
		vis[i][j] = 1;
		for(int k=0;k<4;k++) {
			int x = i + xcord[k];
			int y = j + ycord[k];
			if(x>=0 && x<grid.size() && y>=0 && y<grid[0].size() && vis[x][y] == 0 && grid[x][y] == 0) {
				dfs(grid, vis, x, y);
			}
		}
	}

    int regionsBySlashes(vector<string>& grid) {
        int n = grid.size();
        vector<vector<int>> bigGrid(n*3, vector<int>(n*3,0));
        vector<vector<int>> vis(n*3, vector<int>(n*3,0));
        for(int i=0;i<n;i++) {
            for(int j=0;j<n;j++) {
                if(grid[i][j] == '/') {
                    bigGrid[i*3][j*3+2] = 1;
                    bigGrid[i*3+1][j*3+1] = 1;
                    bigGrid[i*3+2][j*3] = 1;
                }
                else if(grid[i][j] == '\\') {
                    bigGrid[i*3][j*3] = 1;
                    bigGrid[i*3+1][j*3+1] = 1;
                    bigGrid[i*3+2][j*3+2] = 1;
                }
            }
        }
        int c = 0;
        for(int i=0;i<n*3;i++) {
            for(int j=0;j<n*3;j++) {
                if(vis[i][j] == 0 && bigGrid[i][j] == 0) {
                    dfs(bigGrid, vis, i, j);
                    c++;
                }
            }
        }
        return c;
    }
};
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