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?

 

public class Solution {
    public void rotate(int[][] matrix) {
        int tR = 0;
        int tC = 0;
        int dR = matrix.length-1;
        int dC = matrix[0].length-1;
        while (tR < dR) {
        	rotateEdge(matrix, tR++, tC++, dR--, dC--);
        }
    }

	private void rotateEdge(int[][] matrix, int tR, int tC, int dR, int dC) {
		// TODO Auto-generated method stub
		int times = dC - tC;
		int tmp = 0;
		for (int i = 0; i != times; i++) {
			tmp = matrix[tR][tC+i];
			matrix[tR][tC+i] = matrix[dR-i][tC];
			matrix[dR-i][tC] = matrix[dR][dC-i];
			matrix[dR][dC-i] = matrix[tR+i][dC];
			matrix[tR+i][dC] = tmp;
		}
	}
}