Rotate Image

难度：1

需注意n为奇数时中间一列做特殊处理

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/2-1;i++)
		{
			for(int j=0;j<=n/2-1;j++)
			{
				int x=i,y=j;
				int tmp=matrix[x][y];
				matrix[x][y]=matrix[n-1-y][x];
				matrix[n-1-y][x]=matrix[n-1-x][n-1-y];
				matrix[n-1-x][n-1-y]=matrix[y][n-1-x];
				matrix[y][n-1-x]=tmp;
			}
		}
		if(n&1)
		{
			for(int i=0;i<n/2;i++)
			{
				int tmp=matrix[i][n/2];
				matrix[i][n/2]=matrix[n/2][i];
				matrix[n/2][i]=matrix[n-1-i][n/2];
				matrix[n-1-i][n/2]=matrix[n/2][n-1-i];
				matrix[n/2][n-1-i]=tmp;
			}
		}
    }
};