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?

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