cppArr2DForwardBackwardOutput

#include <iostream>

int main()
{

    const int arrSizeY{ 4 };
    const int arrSizeX{ 4 };

    const int arrSize{ arrSizeY * arrSizeX };

    int arrFlat[arrSize]{ 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 };

    int arr[arrSizeY][arrSizeX]{ {1,2,3,4},{5,6,7,8},{9,10,11,12},{13,14,15,16} };

    int direction{ 1 };
    for (int y{ 0 }, begin{}, end{}; y < arrSizeY; ++y, direction *= -1)
    {
        if (direction > 0)
        {
            begin = 0; end = arrSizeX;
        }
        else
        {
            begin = arrSizeX - 1; end = -1;
        }

        for (; begin != end ; begin += direction)
        {
            std::cout << arr[y][begin] << '\t';
            //std::cout << arrFlat[y * arrSizeX + x] << '\t';
        }
        std::cout << '\n';
    }

    return 0;
}