cppRotateArrEffective

#include <iostream>

int main()
{
    const int arrSize{ 10 };
    int arr[arrSize]{ 1,2,3,4,5,6,7,8,9,10 };
    const int arrBegin{ 0 };
    const int arrEnd{ arrBegin + arrSize };
    const int rotatePos{ arrSize - 4 };

    for (int arrIdx{ arrBegin }; arrIdx != arrEnd; ++arrIdx) { std::cout << arr[arrIdx] << ' '; }std::cout << '\n';

    int first{arrBegin};
    int firstNew{ rotatePos };
    int last{arrEnd};

    int read{ firstNew };
    int write{ first };
    int readNext{ first }; // read position for when "read" hits "last"
    int copyElement;

    while (write != read and read != last)
    {
        while (read != last)
        {
            if (write == readNext)
            {
                readNext = read; // track where "first" went
            }

            copyElement = arr[read];
            arr[read] = arr[write];
            arr[write] = copyElement;
            ++read;
            ++write;
        }
        for (int arrIdx{ arrBegin }; arrIdx != arrEnd; ++arrIdx) { std::cout << arr[arrIdx] << ' '; }std::cout << '\n';
        read = readNext;
    }

    //for (int arrIdx{ arrBegin }; arrIdx != arrEnd; ++arrIdx) { std::cout << arr[arrIdx] << ' '; }std::cout << '\n';

    return 0;
}