/*
Alexander DeTrano
2/1/2010
Project Euler - Problem 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.
*/

#include <iostream>
#include <vector>

using namespace std;

int fib(int n);

int main() {

vector<int> myArray; //declare vector to store Fibonacci numbers

int s=34;  // Size needed for vector length
int sum=0; //Initialize sum to 0

//Generate Fibonacci numbers and store in array, add every third
for(int i=0; i<s; i++){
        myArray.push_back(i);
        if (i%3 == 0){
        myArray[i]=fib(i);
        cout<< "fib(" << i << ")= " << myArray[i] << " \n";
        sum+=myArray[i];
cout<<"    Sum = "<< sum <<"\n";
        }
    }

cout<<"Total sum = " << sum;
}

// Function to generate Fibonacci numbers
int fib(int n)
{
	if ( n==0 ) return 0;
	if ( n==1 ) return 1;

	/*for(int i=0;i<5;i++){
	z= fib(n-1) + fib(n-2);
	*/
	return fib(n-1) + fib(n-2);
}

Sorted via problem ID.

Project Euler Problem 2

C++