Problem:
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.
This problem was originally featured on Project Euler.
Algorithm:
Here we only need to learn how to compute Fibonacci numbers.
Program in Java:
/*
* Copyright (C) 2015 Pankaj @ http://codeforwin.blogspot.com/
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
/**
*
* @author Pankaj
*/
public class ProjectEuler2 {
public static void main(String args[] ){
long a,b,c, sum = 0L;
a = 0;
b = 0;
c = 1;
while(c<=4000000) {
if(c%2==0)
sum += c;
a = b;
b = c;
c = a+b;
}
System.out.println(sum);
}
}
Happy coding 😉