Easy C++ explanation || 0 and 1 representation || DFS
Intuition\nEach cell in the input grid can contain a slash / or a backslash \\, which divides the cell into different regions. To identify these regions, we can
# Intuition\nEach cell in the input grid can contain a slash `/` or a backslash `\\`, which divides the cell into different regions. To identify these regions, we can break each cell into a `3x3` grid and mark the cells that contain parts of the slashes. Then, the problem of finding regions becomes one of finding connected components in a graph.\n\n\n# Approach\n1. **Transform the Grid**:\n   - Convert each character in the grid into a 3x3 subgrid.\n   - Use 1s to mark the presence of slashes `/` or backslashes `\\` in the subgrid.\n\n2. **Use DFS for Region Counting**:\n   - Implement a `DFS` function to explore and mark connected regions.\n   - Traverse each cell in the transformed grid and perform DFS whenever a new unvisited cell `(marked with 0)` is encountered.\n\n3. **Count Regions**:\n   - Increment the count of regions for every new DFS call initiated from an unvisited cell.\n\n# Complexity\n- Time complexity:\n$$O((3M) \\times (3N))$$, where $$M$$ is the number of rows and $$N$$ is the number of columns in the input grid. This is because we perform a DFS for each cell in the expanded `3x3` grid.\n- Space complexity:\n$$O((3M) \\times (3N))$$, due to the space needed for the 3x3 expanded grid and the recursive stack space for DFS.\n\n```\nExample - \n\'/\' this can be represented as\n0 0 1\n0 1 0\n1 0 0\n\nex.1 [" /","/ "]\n\n0 0 0 0 0 1\n0 0 0 0 1 0\n0 0 0 1 0 0\n0 0 1 0 0 0\n0 1 0 0 0 0\n1 0 0 0 0 0\n\n```\n# Code\n```\nclass Solution {\npublic:\n    void exploreRegions(vector<vector<int>>&matrix,int i,int j)\n    {\n        if(i < 0 || i >= matrix.size() || j < 0 || j >= matrix[0].size() || matrix[i][j] == 1)\n        {\n            return;\n        }\n        // Mark the cell as visited\n        matrix[i][j] = 1;\n\n        // Explore all four directions\n        exploreRegions(matrix,i+1,j);\n        exploreRegions(matrix,i,j+1);\n        exploreRegions(matrix,i-1,j);\n        exploreRegions(matrix,i,j-1);\n    }\n    int regionsBySlashes(vector<string>& grid) {\n        \n        int rows=grid.size();\n        int cols=grid[0].size();\n\n        vector<vector<int>>matrix(rows*3,vector<int>(cols*3,0));\n        for(int i=0;i<rows;i++)\n        {\n            for(int j=0;j<cols;j++)\n            {\n                if(grid[i][j] == \'/\')\n                {\n                    matrix[i*3][j*3+2]=1;\n                    matrix[i*3+1][j*3+1]=1;\n                    matrix[i*3+2][j*3]=1;\n                }\n                else if(grid[i][j] == \'\\\\\')\n                {\n                    matrix[i*3][j*3]=1;\n                    matrix[i*3+1][j*3+1]=1;\n                    matrix[i*3+2][j*3+2]=1;\n                }\n            }\n        }\n        \n        // Count the number of connected regions\n        int regions=0;\n        for(int i=0;i<rows*3;i++)\n        {\n            for(int j=0;j<cols*3;j++)\n            {\n                if(matrix[i][j] == 0)\n                {\n                    exploreRegions(matrix,i,j);\n                    regions++;\n                }\n            }\n        }\n        return regions;\n    }\n};\n```
['Array', 'Hash Table', 'Depth-First Search', 'Matrix', 'C++']