Rotate Image
Updated Jan 31, 2026
Problem
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.
Constraints
n == matrix.length == matrix[i].length
1 <= n <= 20
-1000 <= matrix[i][j] <= 1000
Examples
Example 1
Input:
matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output:
[[7,4,1],[8,5,2],[9,6,3]]
Example 2
Input:
matrix = [[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]]
Function Signature
def rotate(self, matrix: list[list[int]]) -> None
How to Submit
Implement a Solution class with a rotate method.
Your method will be called with the input parameters and should return the answer.