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Rotate a Matrix In Place

AppleMachine Learning Engineer · Technical Screen
MediumMachine Learning EngineerTechnical ScreenCoding & Algorithms

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This question evaluates proficiency in in-place matrix and array manipulation, spatial data transformation, and reasoning about time and space complexity.

Given an n x n matrix of integers, rotate the matrix 90 degrees clockwise.

Implement the function in Python. You may use a straightforward approach with loops, but the preferred solution should rotate the matrix in place without allocating another n x n matrix.

Example:

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

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

Discuss the time and space complexity of your approach.