# Problem #2

This is problem 2 from project Euler. The task is to find the sum of all the even numbers which make up the Fibonacci sequence that starts with 1 and is less than 4 million.

/* * challenge2.cpp * * This is challenge 2 of project Euler. The objective is to find the sum of the even numbers that lie within * the fibonacci sequence calculated up to 4,000,000. * * Copyright 2012 Bill Heaster <TheCreator@ApexLogic.net> * * 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 argc, char **argv) { //make array, fill with fibonici sequence int myArray [4000]; int a =1; int b = 2; int c = 0; int cnt = 2; int temp, res; //add the beginning to the array myArray[0] = a; myArray[1] = b; while(c < 4000000) { c = a + b; temp = c; if(temp % 2 == 0) //if it is even { myArray[cnt++] = c; } a = b; b = c; } int i; res = 0; for(i = 0; i<cnt; i++) { res+=myArray[i]; } cout<<"the sum of the even numbers within the fibonacci sequence, up to 4 million is: "<<res<<endl; return 0; }