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;

}

};