Project Euler Problem #2 - Even Fibonacci Numbers (in Java)

  1. public class Problem_2_Even_Fibonacci_Numbers {

  3.     /*
  4.         Each new term in the Fibonacci sequence is generated by adding the previous two terms. 
  5.         
  6.         By starting with 1 and 2, the first 10 terms will be:
  7.         1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

  9.         By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.
  10.     */

  12.     public static void main (String[] args) {
  13.         fibonacci(1, 2);
  14.     }

  16.     static int sum = 0, fibonacciSequence = 0;

  18.     public static void fibonacci (int i, int j) {

  20.         fibonacciSequence = j;
  21.         if (fibonacciSequence <= 4000000) { // 4 million
  22.             if (j % 2 == 0) {
  23.                 sum += j;
  24.             }
  25.             fibonacci(j, i + j);
  26.         } else {
  27.             System.out.println(sum);
  28.         }
  29.     }
  30. }
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              Created: February 10, 2014
Completed in full by: Michael Yaworski