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] ]
My code:
class Solution:
def rotate(self, matrix):
"""
:type matrix: List[List[int]]
:rtype: void Do not return anything, modify matrix in-place instead.
"""
length=len(matrix)
self.call_rotate(matrix,0,len(matrix)-1)
def call_rotate(self,matrix,i,j):
if j-i<=0:
return
for k in range(i,j):
tmp_result1=matrix[i][k]
tmp_result2=matrix[k][j]
tmp_result3=matrix[j][j+i-k]
#print(tmp_result3)
tmp_result4=matrix[j+i-k][i]
#Doing transfer
matrix[i][k]=tmp_result4
matrix[k][j]=tmp_result1
matrix[j][j+i-k]=tmp_result2
matrix[j+i-k][i]=tmp_result3
self.call_rotate(matrix,i+1,j-1)