题解 | #顺时针旋转矩阵#

先转置，再水平翻转即可

class Solution {
  public:
    vector<vector<int> > rotateMatrix(vector<vector<int> >& mat, int n) {
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {
                swap(mat[i][j], mat[j][i]);
            }
            reverse(mat[i].begin(), mat[i].end());
        }
        return mat;
    }
};