48. Rotate Image

Solution

class Solution {
public:
    void rotate(vector<vector<int>>& matrix)
    {
        int n = matrix.size();
        for(int i = 0; i < n; ++i)
        {
            for(int j = i; j < n; ++j)
            {
                swap(matrix[i][j], matrix[j][i]);
            }
        }
        for(int i = 0; i < n; i++)
        {
            reverse(matrix[i].begin(), matrix[i].end());
        }
    }
};

• T:
  $O(M\cdot N)$
• S:
  $O(1)$