aloalgoRotate Matrix
Medium
You are given an n x n 2D matrix, which represents an image.
Your task is to rotate this image by 90 degrees clockwise.
Note that:
- The rotation must be performed in-place, meaning you must modify the input 2D
matrixdirectly without allocating another 2Dmatrix.
Do not return anything, instead modify the input matrix
Example 1
Input
[ [1] ]
Output
[ [1] ]
Explanation:
- The original matrix is:
1
- After rotating 90 degrees clockwise, it remains the same:
1
Example 2
Input
[ [1, 2], [3, 4] ]
Output
[ [3, 1], [4, 2] ]
Explanation:
- The original matrix is:
1 2
3 4
- After rotating 90 degrees clockwise, it becomes:
3 1
4 2
Example 3
Input
[ [1, 2, 3], [4, 5, 6], [7, 8, 9] ]
Output
[ [7, 4, 1], [8, 5, 2], [9, 6, 3] ]
Explanation:
- The original matrix is:
1 2 3
4 5 6
7 8 9
- After rotating 90 degrees clockwise, it becomes:
7 4 1
8 5 2
9 6 3
Input
[ [1] ]
Output
[ [1] ]