leetcode661

vector<vector<int>> imageSmoother(vector<vector<int>>& M) {    
    const int N = 151;
    vector<vector<int>> V;    
    for (int i = 0; i < M.size(); i++)//x范围M.size()=3
    {
        vector<int> m1 = M[i];
        vector<int> m2;
        for (int j = 0; j < m1.size(); j++)//y范围m1.size()=3
        {
            int m0 = m1[j];
            //根据i和j找到周边8个节点
            int sum = 0;
            int count = 0;
            for (int x = i - 1; x <= i + 1; x++)
            {
                for (int y = j - 1; y <= j + 1; y++)
                {
                    if (x >= 0 && x <= M.size() - 1 && y >= 0 && y <= m1.size() - 1)
                    {
                        sum += M[x][y];
                        count++;
                    }
                }
            }
            int m = sum / count;
            m2.push_back(m);            
        }
        V.push_back(m2);
    }
    return V;
}