// B2.1.cpp : Defines the entry point for the console application.
//
// Implement a function that accepts an STL container and computes the 
// average of its contents.  Your function must be able to accept more 
// than one type of container, say either a list or a vector, but you 
// are required to show only that it is correct for a vector.

#include "stdafx.h"
#include <vector>
#include <list>
#include <set>
#include <string>
#include <iostream>
using namespace std;

template <class cont> cont::value_type contAvg(const cont &c)
{
  cont::const_iterator it;
  cont::value_type sum = 0;
  if(c.empty())
    return sum;

  for(it=c.begin(); it!=c.end(); ++it)
  {
    sum += *it;
  }
  return (sum/c.size());
}

int _tmain(int argc, _TCHAR* argv[])
{
  std::cout << "\n  Exam B2 - Question #1 "
            << "\n =======================\n";

  set<short int> ss;
  cout << "\n  average of empty set<short int> contents = " << contAvg(ss);
  cout << "\n\n";

  double darray[] = { 1.5, -13.4, 0.58, 53.7, -13 };
  vector<double> vec(&darray[0], &darray[5]);
  cout << "\n  average of vector<double> contents = " << contAvg(vec);
  cout << "\n\n";

  int iarray[] = { 1, 2, 3, 4, 5 };
  list<int> lst(&iarray[0], &iarray[5]);
  cout << "\n  average of list<int> contents = " << contAvg(lst);
  cout << "\n\n";
	return 0;
}