Leetcode-rotate-image

题目描述

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?

还是老问题，这种题目本身不难，但是加了限制条件就变难了，只能在当前空间内做旋转，这个就比较难了。

public class Solution {
public void rotate(int[][] matrix) {
int n = matrix.length;
for(int i=0; i< n/2; i++){
for(int j=0; j<Math.ceil(((double) n) / 2); j++){
int temp = matrix[i][j];
matrix[i][j] = matrix[n-1-j][i];
matrix[n-1-j][i] = matrix[n-1-i][n-1-j];
matrix[n-1-i][n-1-j] = matrix[j][n-1-i];
matrix[j][n-1-i] = temp;
}
}
}
}

需要仔细品味，找出其中门道！