<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 {
private:
    void bfs(int i,int j,vector<vector<int>>&newGrid,vector<vector<int>>&vis)
    {
        queue<pair<int,int>>q;
        q.push({i,j});
        vis[i][j]=1;
        while(!q.empty())
        {
            int row=q.front().first;
            int col=q.front().second;
            q.pop();
            if(row>0 && newGrid[row-1][col]==0 && vis[row-1][col]==0)
            {
                vis[row-1][col]=1;
                q.push({row-1,col});
            }
            if(row<newGrid.size()-1 && newGrid[row+1][col]==0 && vis[row+1][col]==0)
            {
                vis[row+1][col]=1;
                q.push({row+1,col});
            }
            if(col>0 && newGrid[row][col-1]==0 && vis[row][col-1]==0)
            {
                vis[row][col-1]=1;
                q.push({row,col-1});
            }
             if(col<newGrid[0].size()-1 && newGrid[row][col+1]==0 && vis[row][col+1]==0)
            {
                vis[row][col+1]=1;
                q.push({row,col+1});
            }
        }
    }
public:
    int regionsBySlashes(vector<string>& grid) {
        int res=0;
        int n=grid.size();
        int m=grid[0].size();
        vector<vector<int>>newGrid(3*n,vector<int>(3*m,0));  
        for(int i=0;i<n;i++)
        {
            for(int j=0;j<m;j++)
            {
                if(grid[i][j]=='/')
                {
                    newGrid[3*i][3*j+2]=1;
                    newGrid[3*i+1][3*j+1]=1;
                    newGrid[3*i+2][3*j]=1;
                }
                else if(grid[i][j]=='\\')
                {
                    newGrid[3*i][3*j]=1;
                    newGrid[3*i+1][3*j+1]=1;
                    newGrid[3*i+2][3*j+2]=1;
                }
            }
        } 
        vector<vector<int>>vis(3*n,vector<int>(3*m,0));  
        for(int i=0;i<newGrid.size();i++)
        {
            for(int j=0;j<newGrid[0].size();j++)
            {
                if(newGrid[i][j]==0 && vis[i][j]==0)
                {
                    res++;
                    bfs(i,j,newGrid,vis);
                }
            }
        }

        return res;
    }
};
21241