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 m = matrix.size();
for (int i=0; i<m/2; i++)
{
for (int j=i; j<m-1-i; j++)
{
int tmp = matrix[i][j];
matrix[i][j] = matrix[m-1-j][i];
matrix[m-1-j][i] = matrix[m-1-i][m-1-j];
matrix[m-1-i][m-1-j] = matrix[j][m-1-i];
matrix[j][m-1-i] = tmp;
}
}
}
};