Question

I need to figure out how to validate 2 conditions.

1. Check if a previous number has been played.
2. Check if the number is between 1 and 9.

In either case, it should loop back to the beginning. With the first situation, it shouldn’t run till the user enters a number that hasnt been played.

do
{
  cout << "Interesting move, What is your next choice?: ";
  cin >> play;
  Pused[1] = play;

  if(play != Pused[0] && play != cantuse[0] && play != cantuse[1] )
  {
    switch(play)
    {
      default:
        cout << "Your choice is incorrect\n\n";
        break;
    }   
  }
}while(play != 1 && play != 2 && play != 3 && play != 4
    && play != 5 && play != 6 && play != 7 && play != 8 && play != 9);

Dis_board(board);

Answer 1

Instead of do-while loops, i like to use the combination of infinite loops + break statements, like this:

cout << "What is your first choice? ";
while (true)
{
    // Input the choice, including validation

    // Do the move

    if (game_over)
        break;

    cout << "Interesting move; what is your next choice? ";
}

In the code above, the two comments represent code, which may itself contain loops. In order to reduce confusion, you might want to stuff this code into a separate function. For example, to input the choice:

while (true)
{
    cin >> play;
    bool is_illegal =
        play == cantuse[0] ||
        play == cantuse[1] ||
        play < 1 ||
        play > 9;
    if (is_llegal)
        cout << "Your choice is incorrect; please enter again: ";
    else
        break;
}

Note: to implement good handling of user errors, you also have to account for the case when the user enters nonsense instead of a number; look up istream::ignore and ios::clear for that.