[leetcode]48. Rotate Image

Posted 2020-10-10 wilderness

顺时针旋转图片(矩阵)90度

思路：

转置矩阵+水平旋转180度

java代码：

 1 class Solution {
 2     public void rotate(int[][] matrix) {
 3         int tmp = 0;
 4         for(int i=0;i<matrix.length;i++)
 5             for(int j=i;j<matrix[i].length;j++){
 6                 tmp = matrix[i][j];
 7                 matrix[i][j] = matrix[j][i];
 8                 matrix[j][i] = tmp;
 9             }
10         for(int i=0;i<matrix.length;i++)
11             for(int j=0;j<matrix[i].length/2;j++){
12                 if(j!=matrix[i].length-j){
13                     tmp = matrix[i][j];
14                     matrix[i][j] = matrix[i][matrix.length-j-1];
15                     matrix[i][matrix.length-j-1] = tmp;
16                 }
17             }
18     }
19 }

Python代码：

1 class Solution(object):
2     def rotate(self, matrix):
3         matrix[:] = zip(*matrix[::-1])