In-Place Rotate 2D Matrix | Dataford Interview Questions

Rotate an N x N 2D matrix by 90 degrees clockwise in-place.

Implement rotate_matrix(matrix), modifying the input square matrix without allocating another matrix. Return the same matrix after modification so the result can be inspected.

Input: A non-empty N x N matrix of integers.

Output: The rotated matrix, with the original matrix modified in-place.

The rotation must use O(1) additional space.

Constraints

1 <= N <= 1000
matrix has exactly N rows and N columns
-10^9 <= matrix[row][column] <= 10^9
The rotation must be performed in-place
Use O(1) additional space

Function Signature

def rotate_matrix(matrix):

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