Solution
def rotate(self, matrix):
"""
:type matrix: List[List[int]]
:rtype: None Do not return anything, modify matrix in-place instead.
"""
n = len(matrix)
for i in range(n/2):
for j in range(n-n/2):
matrix[i][j], matrix[~j][i], matrix[~i][~j], matrix[j][~i] = \
matrix[~j][i], matrix[~i][~j], matrix[j][~i], matrix[i][j]
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