- Rotate Image Medium
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Share You are given an n x n 2D matrix representing an image.
Rotate the image by 90 degrees (clockwise).
Note:
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.
Example 1:
Given input matrix = [ [1,2,3], [4,5,6], [7,8,9] ],
rotate the input matrix in-place such that it becomes: [ [7,4,1], [8,5,2], [9,6,3] ] Example 2:
Given input matrix = [ [ 5, 1, 9,11], [ 2, 4, 8,10], [13, 3, 6, 7], [15,14,12,16] ],
rotate the input matrix in-place such that it becomes: [ [15,13, 2, 5], [14, 3, 4, 1], [12, 6, 8, 9], [16, 7,10,11] ]
思路：上下反转，然后沿\对角线反转
代码：python3
class Solution:
def rotate(self, matrix: List[List[int]]) -> None:
"""
Do not return anything, modify matrix in-place instead.
"""
length = len(matrix)
for i in range(length//2):
for j in range(length):
print(str(matrix[i][j])+"sdadsa"+str(matrix[length-i-1][j]))
matrix[i][j],matrix[length-i-1][j]=matrix[length-i-1][j],matrix[i][j]
for i in range(length):
for j in range(i+1,length):
matrix[i][j],matrix[j][i]=matrix[j][i],matrix[i][j]
