Question

class Program
{

    static void Main(string[] args)
    {
        Console.WriteLine("Fib 1: ");

        Console.ReadLine();
    }
    long fibonacci1()
    {
        long a = 1, b = 2, c, answer = 0;
        for (int i = 0; answer < 4000000; i++)
        {
            c = a + b;
            if (c % 2 == 0)
            {
                answer += c;
            }
            a = b + c;
            if (a % 2 == 0)
            {
                answer += a;
            }
            b = a + c;
            if (b % 2 == 0)
            {
                answer += b;
            }
        }
        return answer;
    }

    void fibonacci2()
    {
        long[] y = new long [1000000];
        long x = 2;
        long a = y[x - 2] = 1;
        long b = y[x - 1] = 2;
        long n = y[x];
        long answer = 0;

        for (x=2; answer < 4000000; x++)
        {
            n = a + b;
            if(n % 2 == 0)
            {
                answer += n;
            }
        }
        Console.WriteLine("Fib 2: " + answer);
    }
}

This is what I came up with so far. I am trying to come up with 2 ways to come up with the answer.

1) How do you call the two methods?

2) What you guys think about the two ways? I couldn’t test it, but any advice or hints(if I am wrong) Don’t give me the answer:)

---

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.

Answer 1

Make them both static functions like this:

static long fibonacci1()
{
  ...
  return answer;
}

static long fibonacci2()
{
  ...
  return answer;
}

and call them from Main() like this:

{
    long a1 = fibonacci1();
    long a2 = fibonacci2();
    Console.Writeline(...);
}