Rotate a Matrix In Place
Company: Apple
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Technical Screen
Given an `n x n` integer matrix, rotate it **in place** by 90 degrees clockwise.
As follow-ups, explain how to modify the approach to rotate the same matrix:
- 90 degrees counterclockwise
- 180 degrees
You should use `O(1)` extra space other than a few temporary variables.
Example:
Input:
`[[1,2,3],[4,5,6],[7,8,9]]`
After 90 degrees clockwise:
`[[7,4,1],[8,5,2],[9,6,3]]`
After 90 degrees counterclockwise:
`[[3,6,9],[2,5,8],[1,4,7]]`
After 180 degrees:
`[[9,8,7],[6,5,4],[3,2,1]]`
Quick Answer: This question evaluates proficiency in in-place matrix and array manipulation, understanding of spatial transformations, and consideration of space and time complexity constraints.