LeetCode：Rotate Image

You are given an n x n 2D matrix representing an image.

Rotate the image by 90 degrees (clockwise).

Follow up:

Could you do this in-place?

// Source : https://oj.leetcode.com/problems/rotate-image/
// Author : Chao Zeng
// Date   : 2014-12-25

class Solution {
public:
    void rotate(vector<vector<int> > &matrix) {
        int n = matrix.size();
        vector<vector<int>>tmp(n,vector<int>(n));
        for (int i = 0; i < n; i++){
            for (int j = 0; j < n; j++){
                tmp[i][j] = matrix[i][j];
            }
        }
        for (int i = 0; i < n; i++){
            for (int j = 0; j < n; j++){
                matrix[j][n-1-i] = tmp[i][j];
            }
        }
    }
};