（Problem 2）Even Fibonacci numbers

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.

 1 #include <stdio.h>

 2 #include <string.h>

 3 #include <ctype.h>

 4 #include <math.h>

 5   

 6 #define N 4000000

 7   

 8 int a[1001];

 9   

10 void solve()

11 {

12    int a,b,c,n,count=2;

13    a=1,c=0,b=2;

14    n=3;

15    while(c<=N)

16    {

17      c=a+b;

18      if(n%2!=0)

19      {

20         a=c;

21      }

22      else

23      {

24         b=c;

25      }

26      n++;

27      if(c%2==0)

28      {

29        count+=c;

30      }

31    }

32    printf("%d",count);

33 }

34   

35 int main()

36 {

37   solve();

38   getchar();

39   getchar();

40   return 0;

41 }

 

Answer:

4613732