48_Rotate_Image.md

48. Rotate Image

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.

Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [[7,4,1],[8,5,2],[9,6,3]]

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]]

Input: matrix = [[1]]
Output: [[1]]

Input: matrix = [[1,2],[3,4]]
Output: [[3,1],[4,2]]

Constraints:

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

for i in range(len(matrix)):
            for j in range(i, len(matrix)):
                matrix[i][j],matrix[j][i] = matrix[j][i],matrix[i][j]
                
                
        for i in range(len(matrix)):
            left=0
            right=len(matrix)-1
            
            while left < right:
                matrix[i][left], matrix[i][right] = matrix[i][right], matrix[i][left]
                left+=1
                right-=1

Runtime: 32 ms, faster than 81.03% of Python3 online submissions for Rotate Image.
Memory Usage: 14.4 MB, less than 9.01% of Python3 online submissions for Rotate Image.