566. 重塑矩阵

class Solution {
public:
    vector<vector<int>> matrixReshape(vector<vector<int>>& mat, int r, int c) {
    int hang = mat.size();
    int lie  = mat[0].size();
    if(hang * lie != r * c) return mat;
    else{
            vector<vector<int>> ans(r,vector<int>(c));
            for(int i=0;i<hang*lie;i++){
                ans[i/c][i%c] = mat[i/lie][i%lie];
            }
            return ans;
    }
    }
};