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Rotate Image

Detailed guide and Python implementation for the 'Rotate Image' problem.

Problem Statement

Easy

You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).

You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.

Implement a function rotate(matrix: list) -> list that rotates the matrix in-place and returns it.

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

Examples

Example 1
Input
[[1,2,3],[4,5,6],[7,8,9]]
Output
[[7,4,1],[8,5,2],[9,6,3]]
Explanation

The matrix is rotated 90 degrees clockwise. The first column [1,4,7] becomes the first row [7,4,1] reversed.

Example 2
Input
[[5,1,9,11],[2,4,8,10],[13,3,6,7],[15,14,12,16]]
Output
[[15,13,2,5],[14,3,4,1],[12,6,8,9],[16,7,10,11]]
Explanation

Each layer of the 4x4 matrix is rotated 90 degrees clockwise.

Need a Hint?
Consider using Math & Geometry-specific data structures like sets or heaps.
Edge Cases to Watch
  • Empty input structures
  • Single element inputs
  • Large numerical bounds

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