Rotate Image

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 imagein-place, which means you have to modify the input 2D matrix directly.DO NOTallocate 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]
]

Solution1:

方法一

• 将原始矩阵中的元素复制到新矩阵中

• 矩阵中元素位置计算：横纵坐标分别计算

  • 原始矩阵中横坐标为新矩阵中纵坐标

  • 原始矩阵中纵坐标j为新矩阵中height-j-1坐标

方法二

原地坐标转换。如图所示：