# 旋转图像

from typing import List

class Solution:

# 借助一个额外的数组来处理

def rotate_1(self, matrix: List[List[int]]) -> None:

res = []

for i in range(len(matrix[0])):

temp = []

for j in range(len(matrix) - 1, -1, -1):

temp.append(matrix[j][i])

res.append(temp)

matrix[:] = res[:]

# 先整体翻转数组，然后再对称交换

# first reverse up to down, then swap the symmetry

# 1 2 3 7 8 9 7 4 1

# 4 5 6 => 4 5 6 => 8 5 2

# 7 8 9 1 2 3 9 6 3

def rotate_2(self, matrix: List[List[int]]) -> None:

matrix.reverse()

for i in range(len(matrix)):

for j in range(i + 1, len(matrix[i])):

matrix[i][j], matrix[j][i] = matrix[j][i], matrix[i][j]