LeetCode 48. Rotate Image

n x n

Rotate the image by 90 degrees (clockwise).

Follow up:
Could you do this in-place?

class Solution {
public:
    void rotate(vector<vector<int>>& matrix) {
        int length = matrix[0].size();
        for(int i = 0; i < length / 2; i ++){
            swap(matrix[i],matrix[length - 1 - i]);
        }
        
        for(int i = 0; i < length; i ++){
            for(int j = i + 1; j < length; j ++){
                swap(matrix[i][j],matrix[j][i]);
            }
        }
    }
    
   
};