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.
def rotate(self, matrix: List[List[int]]) -> None:
"""
Do not return anything, modify matrix in-place instead.
"""
n = len(matrix)
# iterate through matrix
for i in range(n):
for j in range(i,n):
# transpose the matrix, turning rows into columns and vice versa
matrix[i][j],matrix[j][i] = matrix[j][i],matrix[i][j]
# reverse the resulting rows
matrix[i].reverse()
Posted by Jamie Meyer 19 days ago