【每日一题】48. Rotate Image

Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [[7,4,1],[8,5,2],[9,6,3]]

Input: matrix = [[5,1,9,11],[2,4,8,10],[13,3,6,7],[15,14,12,16]]
Output: [[15,13,2,5],[14,3,4,1],[12,6,8,9],[16,7,10,11]]

Input: matrix = [[1]]
Output: [[1]]

Input: matrix = [[1,2],[3,4]]
Output: [[3,1],[4,2]]

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