Cant make the programm exit after -999 input with summary information-CodePudding

Task: Write a program that would (theoretically) remain open, and allow users to enter numbers throughout the day. Users can enter numbers between 0 and 50. Numbers outside of that range, except -999, are invalid and the user must re-enter a valid number. When a user enters the number, it is added to the sum, and the number of users using the program is incremented. When the value -999. When -999 is entered, the total number of students, total textbooks, and the average number of textbooks are printed.

    #include <iostream>
    using namespace std;

int main () {

    const int minBooks = 0, maxBooks = 50;
    int books;
    int sum=0;
    int student = 1;

do {
    cout << "Books: " << endl;
    cin >> books;
    
    student  ;
    sum  = books;
   
   if (books == -999) {
    cout << "Books: " << sum << "\n" << "Students: " << student << "\n" << "Average" << sum/student<< endl;
    break;
    } 
    
    while (books < minBooks || books > maxBooks)
    {
        cout << "You should at least have " << minBooks << " but no more than " << maxBooks << endl;
        cout << "How many books did you purchased?"<< endl;
        cin >> books;
    } 

} while (books!= -999);

}

My problem is that I cant make a program exit after user input is -999. I tried to change place, use in the loop, out of the loop If -999 works, then it doesn't validate the input

changed while for "if" and now it works however, it doesn't sum up books and takes only last input which is -999

after changing books for sum in two place, now my average is not correct due wrong amount of student; I tried to do decremation but then my average becomes negative

CodePudding user response：

FIGURED IT OUT, THANKS EVERYONE FOR HELP! Here are some changes that helped:

#include <iostream>
using namespace std;

int main () {

const int minBooks = 0, maxBooks = 50;
int books;
int sum=0;
int student = 0;

do {
cout << "Books: " << endl;
cin >> books;
student  ;
sum  = books;

if (books == -999) {
student = student - 1;
sum  = 999;
cout << "Here is your summary: " << endl;
cout << "Books: " << sum << "\n" << "Students: " << student << "\n" << 
"Average: " << sum/student<< endl;
break;
} 

while (books < minBooks || books > maxBooks)
{
    cout << "You should at least have " << minBooks << " but no more than " << maxBooks << endl;
    cout << "How many books did you purchased?"<< endl;
    cin >> books; 
} 

} while (books!= -999);

}