48.py

'''
 You are given an n x n 2D matrix representing an image.

 Rotate the image by 90 degrees (clockwise).
'''
classSolution(object):
defrotate(self, matrix):
"""
 :type matrix: List[List[int]]
 :rtype: void Do not return anything, modify matrix in-place instead.
 """
n=len(matrix)
ifn%2==0:
m=n/2
else:
m=n/2+1

foriinrange(n/2):
forjinrange(m):
temp=matrix[i][j]
matrix[i][j] =matrix[n-j-1][i]
matrix[n-j-1][i] =matrix[n-i-1][n-j-1]
matrix[n-i-1][n-j-1] =matrix[j][n-i-1]
matrix[j][n-i-1] =temp