832. Flipping an Image

1. Description

Given a binary matrix A, we want to flip the image horizontally, then invert it, and return the resulting image.
To flip an image horizontally means that each row of the image is reversed. For example, flipping [1, 1, 0] horizontally results in [0, 1, 1].
To invert an image means that each 0 is replaced by 1, and each 1 is replaced by 0. For example, inverting [0, 1, 1] results in [1, 0, 0].

2. Example

Example 1:
Input: [[1,1,0],[1,0,1],[0,0,0]]
Output: [[1,0,0],[0,1,0],[1,1,1]]
Explanation: First reverse each row: [[0,1,1],[1,0,1],[0,0,0]].
Then, invert the image: [[1,0,0],[0,1,0],[1,1,1]]

Example 2:
Input: [[1,1,0,0],[1,0,0,1],[0,1,1,1],[1,0,1,0]]
Output: [[1,1,0,0],[0,1,1,0],[0,0,0,1],[1,0,1,0]]
Explanation: First reverse each row: [[0,0,1,1],[1,0,0,1],[1,1,1,0],[0,1,0,1]].
Then invert the image: [[1,1,0,0],[0,1,1,0],[0,0,0,1],[1,0,1,0]]

3. Constraints

• 1 <= A.length = A[0].length <= 20
• 0 <= A[i][j] <= 1

4. Solutions

My Accepted Solution

n is the number of pixels in m_matrix
Time complexity: O(n)
Space complexity: O(1)

class Solution 
{
public:
    // vector<vector<int>> flipAndInvertImage(vector<vector<int>>& A) 
    vector<vector<int>> flipAndInvertImage(vector<vector<int>> &m_matrix) 
    {
        for(int i = 0; i < m_matrix.size(); i++)
        {
            reverse(m_matrix[i].begin(), m_matrix[i].end());
            
            for(int j = 0; j < m_matrix[i].size(); j++)
                m_matrix[i][j] ^= 1;
        }
        
        return m_matrix;
    }
};