LeetCode Rotate Image

题目：

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?

class Solution {public:void rotate(vector<vector<int> > &matrix) {int n = matrix.size();for (int i = 0; i < n / 2; i++) {for (int j = i; j < n - 1 - i; j++) {int tmp = matrix[i][j];matrix[i][j] = matrix[n - 1 - j][i];matrix[n - 1 - j][i] = matrix[n - 1 - i][n - 1 - j];matrix[n - 1 - i][n - 1 - j] = matrix[j][n-1-i];matrix[j][n - 1 - i] = tmp;}}}};