Rotate Image

You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees clockwise in-place, meaning you have to modify the input 2D matrix directly without allocating another 2D matrix for the rotation.

Constraints

• n == matrix.length == matrix[i].length
• 1 <= n <= 20
• -1000 <= matrix[i][j] <= 1000