Max Area of Island LeetCode solution in C++

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class Solution {
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 public:
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  int cal(vector<vector<int>> &grid, int i, int j, int &m, int &n) {
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    if (i == m || j == n || i < 0 || j < 0 || grid[i][j] == 0) return 0;
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    grid[i][j] = 0;
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    return 1 + cal(grid, i, j + 1, m, n) + cal(grid, i + 1, j, m, n) + cal(grid, i, j - 1, m, n) +
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           cal(grid, i - 1, j, m, n);
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  }
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  int maxAreaOfIsland(vector<vector<int>> &grid) {
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    int m = grid.size(), n = grid[0].size(), maxArea = 0;
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    for (int i = 0; i < m; i++) {
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      for (int j = 0; j < n; j++) {
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        if (grid[i][j] == 1) {
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          int area = 0;
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          area = cal(grid, i, j, m, n);
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          maxArea = max(maxArea, area);
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        }
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      }
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    }
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    return maxArea;
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  }
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};