Question

1. Please provide a C++ program which faithfully reads a list of non-negative integer scores, ultimately terminating the list reading when the sentinel value (lets use -9999) is entered. The program should then correctly report the number of non-negative scores entered and the arithmetic mean (average) of those scores

2. Demonstrate your programs behavior in response to errors on input (that is, show that it faithfully rejects improper input such as alphabetic characters, decimal points, and commas). Here are some specific examples demonstrating the requirements of your program.

3. Pseudo-code:

Initialize a Sum and Counter to zero

Initialize a loop Done variable to ‘false’, or zero

Provide a brief console output to describe what the program will do

While not Done

Attempt to read the next Input, checking for an integer read failure

If this attempt to read an integer failed then

Clear the input stream status, then ignore the current character on the stream

Repeat the attempt to read an integer until successful

If the Input integer is the sentinel value

Set the loop Done variable to ‘true’, or nonzero

Else if the Input integer is non-negative then

Add one to the Counter

Add the Input to the Sum

Repeat until Done

Compute and display the number of inputs and the average (report 0 average for 0 inputs)

Example Output:

I’ll compute the average of your inputs:

30 45 -9 one junk 100.0 more -1000.8 -9999

Results: 5 non-negative integers entered, average 36.6

// Comment: the non-negative integers read were (30, 45, 100, 0, 8)

Please work off of the code I have provided below.

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

int main()
{
   int a(123456789);
   const int NUM(4);

   cout << "\n Test the stream, the clear() and ignore()\n";
   cout << "Enter " << NUM << " integers: ";
   for (int i = 1; i <= NUM; i++)
   {
       while (!(cin >> a)) // While we have an error reading...
       {
           cin.clear(); // Remove the error state in stream
           cin.ignore(); // Read but ignore the next character
       }
       cout << "\t integer(" << i << ") was: " << a << endl;
   }
   system("pause");
   return 0;
}

Answer 1

#include <iostream>
#include<list>
#include<string>
using namespace std;

int main() {
   //initialize sum and counter to zero
   int sum(0), count(0);
   string number;
   bool done = false;
   list<int> scores;
  
   while(done!=true)
   {
       cin >> number;
       if (stoi(number) >= 0)
       {
           scores.push_back(stoi(number));
           sum += stoi(number);

       }
       else if (stoi(number) < 0 && stoi(number) != -9999)
       {
           //cin.ignore();
           cin.clear();
           continue;
       }
       else
       {
           done = true;
           continue;
       }
       //cin.ignore();
       cin.clear();
       ++count;

   }
   cout << "Non negetive integers read were {";
   list<int>::iterator it = scores.begin();
   while (it != scores.end())
   {
       cout << (*it) << " ";
       it++;
   }
   cout << "}\n";
   cout << "Results: "<<count<<" non-negative integers entered, average " << (float)sum / count << endl;
}

/*Output
30 45 -9 100.0 0 8 -1000.8 -9999
Non negetive integers read were {30 45 100 0 8 }
Results: 5 non-negative integers entered, average 36.6
*/