Help with the program

[Cp9]

Hello everyone. I trying to write a program where the user enters number and counter is moving by that. My problem is how to make a program not start from the very beginning but from next available position. For example, when the user enters 2 , program should go to position 2 and when the user is asked again it should start from position 3. Can someone give me hint how could I get this done? Thanks.

#include <iostream>

using namespace std;

 unsigned short availablePosition = 0;
 
class Counter{
public:
    unsigned short position;
    char row;
public:
    Counter () { row = 'F'; position = 1;};
    void printPosition () {cout << row << position ;};
    void moveCounter ();
};

int main (){

    Counter c;
    c.moveCounter ();
return 0;
}


void Counter::moveCounter(){

    int jumps = 0;
    Counter startPosition, endPosition;

    endPosition.row = startPosition.row;

    endPosition.position = startPosition.position;
do{
    cout << "Enter number of jumps:\t";
    cin  >> jumps;

    endPosition.position = startPosition.position + jumps-1;

   while (endPosition.position > 12)
{
    endPosition.position -= 12;
    startPosition.position = endPosition.position;
    startPosition.row++;

}
    cout << startPosition.row << endPosition.position << "\n";
}while (!(startPosition.row =='K') && (endPosition.position = 12));
}

[JLBorges]

Something along these lines, perhaps:

#include <iostream>

struct counter {

    private:

        static constexpr std::size_t NROWS = 10 ; // "ABCDEFGHIJ"
        static constexpr std::size_t NCOLS = 12 ; // 1 to 12

        // total number of positions
        static constexpr std::size_t NUM_POSITIONS = NROWS * NCOLS ;

        std::size_t curr_pos = 0 ; // note: zero-based

    public:

        // return the current col (1 to 12)
        std::size_t curr_col() const { return curr_pos%NCOLS + 1 ; } // make it one based

        // return the current aow (A to J)
        char curr_row() const {

            static const char rows[] = "ABCDEFGHIJ" ;
            return rows[ curr_pos/NCOLS ] ;
        }

        // jump by n positions
        counter& jump( std::size_t n ) {

            // jump back to beginning if NUM_POSITIONS is exceeded
            curr_pos = ( curr_pos + n ) % NUM_POSITIONS ;
            return *this ;
        }

        friend std::ostream& operator<< ( std::ostream& stm, counter cntr ) {

           return stm << cntr.curr_row() << cntr.curr_col() ;
        }
};

int main()  {

    counter cntr ;
    std::cout << "initially at " << cntr << "\n\n" ;

    std::size_t n ;
    while( std::cout << "#jumps (enter q to quit)? " && std::cin >> n ) {

        // C++17: can combine these two into one statement
        std::cout << '\n' << cntr << " ==> " ;
        std::cout << cntr.jump(n) << "\n\n" ;
    }
}