#include <iostream>
#include <iomanip>
#include <string>

#define NUMTESTS 3

using namespace std;

/**************************/
/*  Function Prototypes   */
/**************************/
// Get the student's SSN
string getSSN();
// Get each test score --> call 3 different times
float getTestScore(string testNum);
// Calculate the average of the three test scores
float calcAvg(float score1, float score2, float score3);
// Print student's SSN and test average
void printStuInfo(string ssn, float testAvg);

int main()
{
  float test1, test2, test3;
  float avg;
  string ssn;

  ssn = getSSN();
  test1 = getTestScore("one");
  test2 = getTestScore("two");
  test3 = getTestScore("three");

  avg = calcAvg(test1, test2, test3);
  
  printStuInfo(ssn, avg);

  return 0;
}  // end main


// Function name: getSSN
// Description: get student's SSN
// Parameters: none
// Return value: the student's SSN
string getSSN()  
{
  string socialNum;

  cout << "Enter student's SSN: ";
  cin >> socialNum;

  return socialNum;
}  // end function getSSN



float getTestScore(string testNum)
{
  float score;

  cout << "Enter test score number " << testNum << " for a student: ";
  cin >> score;
  if (score < 0)
    {
      cout << "Test score must be >= 0!" << endl << endl;
      exit (0);
    }  // end if score < 0

  return score;
}  // end function getTestScore


float calcAvg(float score1, float score2, float score3)
{
  float sum;
  float ave;

  sum = score1 + score2 + score3;
  ave = sum / NUMTESTS;

  return ave;
}  // end function calcAvg


void printStuInfo(string ssn, float testAvg)
{
  cout << fixed << showpoint << setprecision(2);
  cout << endl << endl;
  cout << "Test average for " << ssn << " is " << testAvg << endl << endl;

  return;
}  // end function printStuInfo