顺时针打印矩阵

class Solution {
    void ccwVector(vector<vector<int> >&a){

        vector<vector<int>>b = a;
        if (a.size() <= 0)
            return;

        //初始化矩阵的空间
        a.clear();

        a.resize(b[0].size());

        for (int i = 0; i < a.size(); i++){
            a[i].resize(b.size());
        }
        //制作逆时针转向的新矩阵
        for (int i = 0; i < b[0].size(); i++){
            for (int j = 0; j < b.size(); j++){
                a[b[0].size() - i - 1][j] = b[j][i];
            }

        }
    }


public:
    vector<int> printMatrix(vector<vector<int> > matrix) {

        vector<int>result;
        vector<vector<int>>::iterator i;
        while (matrix.size()>0){
            i = matrix.begin();
            for (auto j = (*i).begin(); j!=(*i).end(); j++){
                result.push_back(*j);
            }
            matrix.erase(matrix.begin());
            ccwVector(matrix);
        }
        return result;
    }
};

int main(){

    Solution s;
    vector<vector<int>>a(4, vector < int>(4));
        int v = 1;
        //初始化一个矩阵。
        for (int i = 0; i < a.size(); i++){
            for (int j = 0; j < a[0].size(); j++){
                a[i][j] = v++;
                cout << a[i][j] <<"  ";
            }
            cout << endl;
        }
        cout << "-----------" << endl;
        vector<int>b = s.printMatrix(a);
        for (int i = 0; i < b.size(); i++){
                cout<<b[i]<<"   " ;
        }
        cout << endl;
}