首页 > 代码库 > 48. Rotate Image
48. Rotate Image
You are given an n x n 2D matrix representing an image.
Rotate the image by 90 degrees (clockwise).
Follow up:
Could you do this in-place?
The idea was firstly transpose the matrix and then flip it symmetrically. For instance,
1 2 3
4 5 6
7 8 9
after transpose, it will be swap(matrix[i][j], matrix[j][i])
1 4 7
2 5 8
3 6 9
Then flip the matrix horizontally. (swap(matrix[i][j], matrix[i][matrix.length-1-j])
7 4 1
8 5 2
9 6 3
/** No extra space 2 steps*/ public void rotate(int[][] matrix) { int row = matrix.length; int col = matrix[0].length; for(int i = 0 ; i < row; i++){ for(int j = i; j < col ; j++){ //对角线 int temp = matrix[i][j]; matrix[i][j] = matrix[j][i]; matrix[j][i] = temp; } } // step 1 for(int i = 0 ; i < row; i++){ for(int j = 0; j < row/2 ; j++){ //col -> row int temp = matrix[i][j]; matrix[i][j] = matrix[i][row-1-j]; matrix[i][row-1-j] = temp; } } // step 2 }
48. Rotate Image
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。