<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>

#include <vector>
#include <queue>
#include <string>
#include <iostream> // For cout
using namespace std;

class Solution {
public:
    void setMatrixForward(int i, int j, vector<vector<int>>& matrix) {
        matrix[3*i][3*j + 2] = 1;
        matrix[3*i + 1][3*j + 1] = 1;
        matrix[3*i + 2][3*j] = 1;
    }

    void setMatrixBackward(int i, int j, vector<vector<int>>& matrix) {
        matrix[3*i][3*j] = 1;
        matrix[3*i + 1][3*j + 1] = 1;
        matrix[3*i + 2][3*j + 2] = 1;
    }

    void dfs(vector<vector<int>>& grid, int row, int col, vector<vector<int>>& visited) {
        visited[row][col] = 1;
        queue<pair<int, int>> q;
        q.push({row, col});
        int n = grid.size();
        int m = grid[0].size();

        // Directions array for moving up, down, left, and right
        int deltas[4][2] = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};

        while(!q.empty()) {
            int curRow = q.front().first;
            int curCol = q.front().second;
            q.pop();

            for (int i = 0; i < 4; i++) {
                int nrow = curRow + deltas[i][0];
                int ncol = curCol + deltas[i][1];

                if (nrow >= 0 && nrow < n && ncol >= 0 && ncol < m && 
                    grid[nrow][ncol] == 0 && !visited[nrow][ncol]) {
                    visited[nrow][ncol] = 1;
                    q.push({nrow, ncol});
                }
            }
        }
    }

    int regionsBySlashes(vector<string>& grid) {
        int n = grid.size();
        vector<vector<int>> matrix(3*n, vector<int>(3*n, 0));
        for (int i=0; i<n; i++) {
            for (int j=0; j<n; j++) {
                if (grid[i][j] == '/') {
                    setMatrixForward(i, j, matrix);
                } else if (grid[i][j] == '\\') {
                    setMatrixBackward(i, j, matrix);
                }
            }
        }

        vector<vector<int>> visited(3*n, vector<int>(3*n, 0));
        int count = 0;
        for (int i=0; i<3*n; i++) {
            for (int j=0; j<3*n; j++) {
                if (matrix[i][j] != 1 && visited[i][j] == 0) {  // Corrected `and` to `&&`
                    dfs(matrix, i, j, visited);
                    count++;
                    // Comment this out if you don't need debug info
                    // cout << "for (" << i << ", " << j << ") count = " << count << endl;
                }
            }
        }
        return count;
    }
};

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