leetcode[48]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(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 temp=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]=temp;
        }
    }
    return;
}
};