rotate image

code

class Solution {
public:
    void rotate(vector<vector<int>>& matrix) {
        vector<vector<int>> ret;
        int m = matrix.size();
        int n = matrix[0].size();

        for(int i = 0; i<n; i++)
        {
            vector<int> tmp(m, 0);
            ret.push_back(tmp);
        }

        for(int i = 0; i<m; i++)
        {
            for(int j = 0; j<n; j++)
            {
                ret[j][m-1-i] = matrix[i][j];
            }
        }

        matrix = ret;
    }
};