One possible solution for problem 2 on the Project Euler website

ProblemTwo.cpp

/*
 * Project Name:            Problem Two
 * Solution Name:           Problem Two
 * Original creation date:  03/07/2011
 * Edit date:               18/01/2013
 * Programmer name:         Jamie Taylor (aka "GaProgMan")
 * File name:               ProblemTwo.cpp
 *
 * Purpose of the project:
 * This code is my solution for "Problem Two" listed
 * on Project Euler. The original problem is listed
 * in the comment block below
 * 
 * Problem Two, from Project Euler.
 *   URL: http://projecteuler.net/index.php?section=problems&id=2
 *   Each new term in the Fibonacci sequence is generated
 * by adding the previous two terms. By starting with 1
 * and 2, the first 10 terms will be:
 *   1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
 *   By considering the terms in the Fibonacci sequence
 * whose values do not exceed four million, find the sum
 * of the even-valued terms.
 *
 * Chosen Algorithm:
 *    Step 1) add up the Fibonacci sequence, until we
 *            reach 4 million (4000000) and make a note
 *            of the final number
 *    Step 2) sum all of the even numbers between 0 and
 *            the final number in step 1
 *
 * Algorithm discussion:
 *   Running through my fibonacci calculation method
 * (CalculateFibonacci() ) tells me something quite
 * useful.
 *   33 steps through the fibonacci sequence give
 * the answer 3,524,578 34 steps through the fibonacci
 * sequence give the answer 5,702,887
 *   Since the Fibonacci sequence is a sequence of whole
 * numbers (1,2,3... etc), then step 33 is where I shall
 * stop. This means that I need to sum the even valued
 * terms between 1 and 33
 *
 *    GNU Copyright information
 *    Copyright 2011 Jamie Taylor <jamie@taylorj.org.uk>
 *
 *    This program is free software; you can redistribute
 *        it and/or modify it under the terms of the GNU General
 *        Public License as published by the Free Software
 *        Foundation; either version 2 of the License, or (at
 *	your option) any later version.
 *
 *	This program is distributed in the hope that it will
 *	be useful, but WITHOUT ANY WARRANTY; without even the
 *	implied warranty of MERCHANTABILITY or FITNESS FOR A
 *	PARTICULAR PURPOSE.  See the GNU General Public
 *	License for more details.
 *
 *	You should have received a copy of the GNU General
 *	Public License along with this program; if not, write
 *	to the Free Software Foundation, Inc., 51 Franklin
 *	Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

#include <iostream>

using namespace std;

int main () {
  int initial = 1;
  int previous = 1;
  int total = 0;
  int sum = 0;
  
  do {
    total = initial + previous;
    if ( total % 2 == 0 )
      sum += total;
    initial = previous;
    previous = total;
  }  while ( total < 4000000 );
  cout << "The sum of all even terms (up to 4 mil): " << sum << endl;
  char ch;
  cin >> ch;
  return 0;
}