Rotate Image
You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees clockwise.
You must rotate the image in-place, which means you must modify the input matrix directly. Do not allocate another 2D matrix to perform the rotation.
Example 1
1 2 3 4 5 6 7 8 9
Input
matrix = [[1,2,3],[4,5,6],[7,8,9]]Output
[[7,4,1],[8,5,2],[9,6,3]]The first row becomes the last column, the second row becomes the middle column, and the third row becomes the first column after a 90-degree clockwise rotation.
Example 2
5 1 9 11 2 4 8 10 13 3 6 7 15 14 12 16
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]]Rotating the 4 x 4 matrix clockwise moves each element to its corresponding rotated position.
Constraints
- n == matrix.length == matrix[i].length
- 1 <= n <= 20
- -1000 <= matrix[i][j] <= 1000