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. |

The problem here is twofold, namely:

- To find all the terms in the Fibonacci sequence that are even
**AND** less than four million, and,
- Find the sum of all those terms.

Figuring out the Fibonacci sequence is relatively easy for a computer (as it’s just an iterated sum, and sums are P problems). However, you don’t want to just generate a zillion numbers and sum them blindly. Heed these words, even more if you’re just learning code: stating the problem correctly is half the battle. In this particular case, once you know what you should do *in theory*, your code should follow it. Namely, you should:

- Figure out the terms of the Fibonacci sequence,
- Take those that are even
**AND** less than four million; and
- Add these together, print the result.

An elegant algorithm doesn’t come out of nowhere, it’s the result of an elegant problem/solution statement. The lesson? Learn to state the problem and its solution in the simplest terms you can.

← Project Euler Guide: Problem 1 | **Project Euler Guide: Problem 2** | Project Euler Guide: Problem 3 →