Solution: Rotate an Image

Problem Statement

Rotate an n x n matrix by 90 degrees clockwise, in place, and return it.

Examples

Example 1

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

Example 2

• Input: matrix = [[1, 2], [3, 4]]
• Expected Output: [[3, 1], [4, 2]]

Example 3

• Input: matrix = [[5]]
• Expected Output: [[5]]

Where the answer comes from

Write down where one value has to end up. The value at row r, column c moves to row c, column n - 1 - r