Description

Submission

class Solution {
public:
    int islandPerimeter(vector<vector<int>>& grid) {
        res = 0;
        height = grid.size();
        width = grid[0].size();
        for(int i = 0; i < height; ++i) {
            for(int j = 0; j < width; ++j) {
                if(grid[i][j] == 1)
                    res += boxPerimeter(i, j, grid);
            }
        }
        return res;
    }
private:
    int res;
    int width;
    int height;
    
    int boxPerimeter(int i, int j, vector<vector<int>>& grid)
    {
        return getBoxAttr(i - 1, j, grid) + getBoxAttr(i + 1, j, grid) + 
            getBoxAttr(i, j - 1, grid) + getBoxAttr(i, j + 1, grid);
    }
    
    int getBoxAttr(int i, int j, vector<vector<int>>& grid)
    {
        if(i < 0 || i == height || j < 0 || j == width) return 1;
        if(grid[i][j] == 1) return 0;
        return 1;
    }
};