C# Implementation of Problem 2
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1/*
2Project Euler Problem 2
3
4This is a port of the optimized version found in python. For a proof of why this
5works, see that implementation
6
7Problem:
8
9Each new term in the Fibonacci sequence is generated by adding the previous two
10terms. By starting with 1 and 2, the first 10 terms will be:
11
121, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
13
14By considering the terms in the Fibonacci sequence whose values do not exceed
15four million, find the sum of the even-valued terms.
16*/
17using System;
18
19namespace Euler
20{
21 public class p0002 : IEuler
22 {
23 public object Answer()
24 {
25 int answer = 0,
26 i = 2,
27 j = 8,
28 tmp = 0;
29
30 while (i < 4000000)
31 {
32 answer += i;
33 tmp = 4 * j + i;
34 i = j;
35 j = tmp;
36 }
37
38 return answer;
39 }
40 }
41}