Python Example

def rotateImage(image):
    """ Rotates an NxN matrix, or image, by 90 degrees 
    (clockwise) in place.

    Args:
        image (list of lists of obj): An NxN matrix of any object.

    Returns:>
        (list of lists of obj): The given image rotated by 90 degrees 
            clockwise.
    """
    number_of_layers = (len(image) + 1) // 2
    
    for layer in range(number_of_layers):
        rotate_image_layer(image, layer)
        
    return image


def rotate_image_layer(image, layer):
    """ Rotates a single layer of an NxN matrix, or image,
    by 90 degrees clockwise.

    Note:
        The outer most layer is 0, and the inner most layer
    is `len(image) + 1 // 2`.

    Args:
        image (list of lists of obj): An NxN matrix of any object.
        layer (int): The layer number of the given image.

    """
    start = layer
    end = len(image) - layer - 1
    
    for col in range(start, end):
        row = end - col + start
        
        temp = image[row][start]
        
        image[row][start] = image[end][row]
        image[end][row] = image[col][end] 
        image[col][end] = image[start][col]
        image[start][col] = temp