So if a user only wanted to put in an initial 3 numbers and because a mistake was made needed to leave the add_values to edit but then subsequently wanted to return to finish putting in 7 more numbers
well im not really sure what your asking but u could create a a counter variable and have the user say how many values he wants to enter then use ur counter in the for loop
int counter;
cin >> counter;
for(int i = 0; i < counter; i++)
{}
or... you could have it where if the user inputs a somthing like "leave" then it will break the loop