/*
   testrep9.cpp
   CIS 150
   6/10/2008
   David Klick
  
   Demonstration of priming read. This program adds
   up the numbers a user enters. One problem is that
   the sentinel value used eliminates one possible
   integer (-999) that the user may want to enter.
*/

#include <iostream>
using std::cout;
using std::cin;

void cont();

int main() {
   int num;   // variable for user input
   int sum;   // accumulator
   
   // display informational message and reset sum
   cout << "Adding machine program\n";
   sum = 0;
   
   // get first input from user (priming read)
   cout << "Enter an integer (-999 to exit): ";
   cin >> num;
   
   // keep going through loop until user enters -999
   while (num != -999) {
      // add user entry to accumulator
      sum += num;
      
      // get next user entry
      cout << "Enter an integer (-999 to exit): ";
      cin >> num;
   }
   
   // display result
   cout << "The sum is " << sum << '\n';

   cont();
   return 0;
}

void cont() {
   if (cin.rdbuf()->sungetc() != -1 && cin.get() != '\n') cin.ignore(80,'\n');
   cout << "Press enter to continue...";
   cin.get();
}

/*
   Sample output:

   Adding machine program
   Enter an integer (-999 to exit): 25
   Enter an integer (-999 to exit): 15
   Enter an integer (-999 to exit): -10
   Enter an integer (-999 to exit): -999
   The sum is 30
*/