Neetcode: Rotate Image

Instructions

Given a square n x n matrix of integers matrix, rotate it by 90 degrees clockwise.

You must rotate the matrix in-place. Do not allocate another 2D matrix and do the rotation.

Example 1:

Input: matrix = [
  [1,2],
  [3,4]
]

Output: [
  [3,1],
  [4,2]
]

Example 2:

Input: matrix = [
  [1,2,3],
  [4,5,6],
  [7,8,9]
]

Output: [
  [7,4,1],
  [8,5,2],
  [9,6,3]
]

Constraints:

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